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Swedish National Defense Research Institute FOA Report
Department of Planning and Operations Research C10045-M3(E5)
S-10450 Stockholm July 1978
DECsystem-10 SIMULA Language Handbook Part III
==============================================
(The DECsystem-10 SIMULA Utility Program Library)
BY Stefan Arnborg, Lars Enderin, Mats Ohlin, Stephan Oldgren and
Jacob Palme.
ABSTRACT
The DECsystem-10 SIMULA Language Handbook contains the
information necessary for an applications programmer who
intends to use SIMULA on a DECsystem-10 computer.
Part I describes the SIMULA programming language.
Part II contains special information for DECsystem-10.
Part III describes the utility program library, which
includes:
> The SAFEIO package for safe conversational terminal interface.
> Utility routines for inserting a help facility into the
conversational terminal communication, where the appropriate
help message at each point in the program can be selected from
a file containing several messages.
> Routines for accessing date, time etc.
> Routines to allow writing real-time programs in SIMULA (e.g.
programs which can communicate simultaneously with more than
one user terminal.) These routines do not work with
DECsystem-20.
> Routines for binary (un-formatted) I/O.
> Routines for record-oriented I/O.
> Routines for file handling.
> A utility package of routines for character string (TEXT)
handling, with routines for searching, splitting,
concatenating, hashing etc.
> Routines for in-core sorting and summation.
This document reflects the software as of version 4 of the
DECsystem-10 SIMULA system.
Last update 1978-05-23.
DECsystem-10 SIMULA Language Handbook, part III Page 2
SEARCH KEY
Computer, Programming, Programming Language, SIMULA,
DECsystem-10, Digital Equipment, Algol 60, Fortran, Program
library, file handling, input/output, conversational
programming, real time, error handling, string handling,
character handling, text handling, sorting.
CONDITIONS OF RELEASE
The information in this document is subject to change
without notice. The Swedish National Defence Research
Institute assumes no responsibility for any errors that may
appear in this document, in the programs described therein
or in the SIMULA system itself. No promise is made to
implement any of these programs, especially not those marked
"NOT READY".
This document and the software described in it is furnished
to the user for use on a DECsystem-10 computer system and
may be copied only for use on such systems, except as may
otherwise be provided in writing by the Swedish National
Defence Research Institute.
ACKNOWLEDGEMENT
Part of section 4.1 has been adapted from the similar text
for the IBM 360/370 SIMULA System, written by Karel Babcicky
at the Norwegian Computing Center.
Copyright 1976, 1977 by The Swedish National Defense
Research Institute and (partly) The Norwegian Computing
Center.
SOME OF THE PROCEDURES ARE NOT YET WRITTEN
This preliminary version of part III of the handbook
includes some procedures which have not yet been
implemented. Their descriptions are only proposals. Some
of these procedures may eventually be implemented in a
different fashion, if at all.
These procedures are marked [NOT READY] in section 0.2 but
they are not always marked [NOT READY] in the following
chapters. Always refer to section 0.2 to check if a
procedure is available.
DECsystem-10 SIMULA Language Handbook, part III Page 3
TABLE OF CONTENTS
0. INTRODUCTION
0.1 HOW TO GET ACCESS TO THE LIBRARY
0.2 SUMMARY LIST OF ROUTINES
1. UTILITY PACKAGES
1.1 APPLICATION PACKAGES
1.2 DEMONSTRATION PROGRAMS
2. SIMULA SOURCE PROGRAM CONVERSION PROGRAMS
3. DIRECTFILE HANDLING PROGRAMS
4. PROCEDURES NOT WRITEABLE IN SIMULA
4.1 TIME AND DATE
4.2 BASIC ASSEMBLY PROCEDURES FOR REAL TIME
4.3 INPUT/OUTPUT
4.3.1 ASCII-FORMATTED I/O
4.3.2 UNFORMATTED (BINARY) I/O
4.3.3 FILE HANDLING
4.4 CONTROLLED ERROR HANDLING
4.5 SCHEDULING AND JOB CONTROL
4.6 MEMORY HANDLING
[These facilities are not yet ready.]
4.6.1 PRIMARY MEMORY HANDLING
4.6.2 VIRTUAL MEMORY HANDLING (OR OVERLAY
FACILITY)
4.7 ENVIRONMENT ENQUIRY
4.8 PACKING INTO PARTS OF WORDS
DECsystem-10 SIMULA Language Handbook, part III Page 4
4.8.1 PACK AND UNPACK, PARAMETERS
4.8.2 PACK AND UNPACK, ERROR HANDLING
4.8.3 PACK AND UNPACK, METHODS OF PACKING
4.8.4 PACK AND UNPACK, METHODS OF UNPACKING
4.8.5 PACK AND UNPACK, EXAMPLES
4.9 MIN AND MAX
5. ROUTINES WRITEABLE IN SIMULA.
5.1 PARTITIONING OF TEXTS
5.2 SEARCHING AND TESTING OF TEXTS
5.3 OPERATIONS ON TEXTS
5.4 INPUT/OUTPUT
5.5 SORTING AND SUMMATION ETC.
5.6 RANDOM NUMBER GENERATION ETC.
5.7 SIMULA VERSIONS OF SYSTEM CLASSES
6. SWEDISH LANGUAGE TEXT HANDLING AND INPUT/OUTPUT
7. UTILITIES SPECIFIC TO DECSYSTEM-10
APPENDIX A - REALTIME - A SCHEDULER FOR TERMINAL PROCESSES
APPENDIX B - CONTROLLED ERROR HANDLING
APPENDIX C - INDEX
DECsystem-10 SIMULA Language Handbook, part III Page 5
0. INTRODUCTION
------------
The intention is to include in this document descriptions of
utility programs, classes and procedures of general interest
to users of SIMULA on the DECsystem-10.
Examples:
> Programs for editing and generating SIMULA source programs.
> Useful program packages written in SIMULA such as data base
packages, graphic packages, conversational I/O packages.
> Useful MACRO 10 programs to be called from SIMULA, e.g. for
object and binary I/O, access to monitor facilities like the
clock.
The programs described here will be distributed to
DECsystem-10 users through the DECUS library, either as
separate programs or on the SIMULA distribution tape.
Anyone who has submitted a program to the DECUS library,
such that the program is also suitable for inclusion in the
SIMULA program library, is invited to send us a copy of the
program and its documentation. If we accept the program, we
will include its description in future editions of this
handbook. Contributions in the form of procedures and
classes of general interest are also welcome, preferably in
machine-readable form with full documentation. We may
modify the code to better fit the rest of the system, if you
allow us to do so. We cannot promise to include your
contributions, however.
0.1 HOW TO GET ACCESS TO THE LIBRARY
Most of the procedures and classes described in this
document are available in the library files LIBSIM.ATR and
LIBSIM.REL. These files should normally be available on the
SYS: area on your computer, but you can also keep them on
your own disk area. Main programs to be executed directly
are available as separate .SAV (.EXE) files, not in the
LIBSIM files.
Library procedures will be available to your program if you
declare them as external at the beginning of your program,
e.g:
EXTERNAL CLASS safeio;
EXTERNAL INTEGER PROCEDURE hash;
You need not mention any explicit filename if you are using
LIBSIM on the SYS area or on your own area. An external
declaration in a separately compiled segment (module) must
DECsystem-10 SIMULA Language Handbook, part III Page 6
be repeated in all dependent modules including the main
program. Please note that when you use modules in LIBSIM
that are coded in SIMULA you will sometimes have to
explicitly declare other LIBSIM routines. The compiler will
duly tell the user which declarations are missing.
If you want to use other libraries, see the DECsystem-10
SIMULA Language Handbook part II chapter 7.1.1.
Normally, when you load your programs with the LOAD, EXECUTE
or DEBUG commands of DECsystem-10, you need not mention the
names of any separately compiled classes or procedures.
Just write:
.EXECUTE myprog
if your program has the name myprog. Any external classes
or procedures declared as such inside myprog will
automatically be loaded.
If you cannot find the necessary .SIM, .REL, .ATR, .HLP,
.MAN or .DOC files on the SYS:, HLP: or DOC: areas on your
computer, they may still be found on the SIMULA distribution
tape. REL and ATR files for separately compiled procedures
or classes can be found in the library LIBSIM (.ATR and
.REL) on the SYS: area.
For procedures written in MACRO-10, there is usually no
separate .SIM specification file. Instead, the .MAC file is
written such that when you compile it with the SIMULA
compiler, the necessary .ATR file is produced.
In addition to the utilities listed below, a SIMULA
programmer has access to a number of built-in standard
procedures. These are described in appendix B to the
DECsystem-10 SIMULA Language Handbook part I.
The procedures, classes and main programs listed below are
described in this document.
DECsystem-10 SIMULA Language Handbook, part III Page 7
0.2 SUMMARY LIST OF ROUTINES
0.2 SUMMARY LIST OF ROUTINES
The first column for each program indicates type of result for
function procedures, K for separately compiled classes, M for
main programs (not in LIBSIM). The following letters indicate
parameter types.
Letter codes in this list:
..=repetition of parameter, R=REAL, L=LONG REAL, I=INTEGER,
C=CHARACTER, T=TEXT, X=REF, B=BOOLEAN, G=LABEL, a=ARRAY,
P=PROCEDURE, K=CLASS, M=MAIN PROGRAM.
An asterisk (*) indicates efficient, MACRO-10 coded procedure.
1. UTILITY PACKAGES
1.1 APPLICATION PACKAGES
K T,T SAFEIO Safe conversational terminal I/O.
See SAFEIO.HLP and SAFEIO.MAN
K T SAFEI SAFEIO without file handling
facilities
K SAFMIN Small, simplified version of SAFEI
K T,T SIMEIO Same as SAFEIO but prefixed with
SIMULATION
K T SIMEI Same as SAFEI but prefixed with
SIMULATION
K SIMMIN Same as SAFMIN but prefixed with
SIMULATION
K SIMDBM CODASYL DBTG type DBMS system.
Consists of the external classes
SIMDBM (DBMMIN), DBMSET and the main
programs DBDUMP, DBLOAD, DBSORT,
FETCH, HMAKE, TRANSF, LOAD, DIRED,
SPEC, PREP and PREP2
K I,I STORE Simple text-oriented DBMS
K SELECT Boolean condition searching TEXT or
FILE
K I,I,I GPSSS GPSS-like queue simulation package
K I,I,I,C,I GPSSST GPSSS with more automatic trace
facilities
K FIGURE Plot package for Tektronix plotter.
GRAPHI, COSYS, COSYSF and RUBOUT are
also part of this package. See
FIGURE.HLP
K I,I,X,B,I VISTA Full control of alphanumeric display
screen, e.g. to produce moving
pictures
K I,I,X,B,I FORM Form fill in data entry, subclass of
VISTA
DECsystem-10 SIMULA Language Handbook, part III Page 8
0.2 SUMMARY LIST OF ROUTINES
P I,I,I,T GETVIS Terminal type input for VISTA
K T DAHELP Gives user help message when running
SIMULA program. Uses direct-access
file to store help messages. See
DAHELP.HLP
B T,T,I,I SQHELP Gives user help message when running
SIMULA program. Uses sequential file
to store help messages
1.2 DEMONSTRATION PROGRAMS
M (Not listed here)
2. SIMULA SOURCE CODE CONVERSION PROGRAMS
[These are main programs, and thus
not placed in LIBSIM]
M SIMED Prettyprinting, cleaner layout,
indentation of BEGIN-END, no semantic
change of program
M SIMSTR [NOT READY] Automatic structure
abstract of source program
M SIMEXP Combines separately compiled modules
into one module
M SIMIBM Conversion to IBM Simula
M IBMSIM Conversion from IBM Simula
M CDCSIM Conversion from CDC Simula
M FQCRED Adds frequency count statements to a
SIMULA program
M FQCLST Edits SIMULA source program with
frequency measurements
3. DIRECTFILE HANDLING PROGRAMS
M DIRED Edits a directfile
M MAKEDF Converts sequential files to
directfiles and vice versa
M FETCH General-purpose SIMDBM Data Base
Manipulator
M MAKHLP Creates help file for use with DAHELP
4. PROCEDURES NOT WRITEABLE IN SIMULA
DECsystem-10 SIMULA Language Handbook, part III Page 9
0.2 SUMMARY LIST OF ROUTINES
4.1 TIME AND DATE
T TODAY(*) Gives TEXT with date: yyyy-mm-dd
I DAYNO Number of this day in current year
T DAYTIME(*) Gives TEXT with hh:mm:ss
R CLOCKTIME(*) Gives REAL with time of day in
seconds
R CPTIME(*) Gives LONG REAL with CPU time in
seconds
? ? TIMELIMIT [NOT READY] Sets time limit for
current execution
4.2 REAL TIME
B X INPUTCHECK(*) Anything to read on file X?
P R SLEEP(*) Delays execution for R real seconds
I Xa,R INPUTWAIT(*) Sleeps until anything to read
K REALTIME Scheduler for terminal processes
4.3 INPUT/OUTPUT
I X LINECOUNT(*) Returns LINESPERPAGE setting
I X FILENAME(*) Gives TEXT with FILE object
generation parameter
C GETCH(*) Inputs character, will not wait for
carriage return (input from
controlling terminal only)
B R TTYCHECK(*) Checks if a character has been typed
in at the controlling terminal
P X,C,I OUTCHR(*) Outputs character bypassing image
P X FORCEOUT(*) Terminal output buffer to terminal
C X INSINGLECHAR(*) Inputs character, does not wait for
carriage return (Input from disk or
controlling TTY)
C X INSNGL(*) As INSINGLECHAR, but line mode (waits
for break character)
P ILRCPa.. READ(*) Reads many values in standard format
P ILRCTPa.. WRITE(*) Writes many values in standard format
I X,RLICBTXa.. OUTPUT(*) Binary output
I X,RLICBTXa.. INPUT(*) Binary input
I RLICBTXa.. PUTSIZE(*) How much will OUTPUT write?
B X,I BYPASS(*) [NOT READY] Bypass I characters in a
file
B X,LRIC LOOK(*) [NOT READY] Binary one-word lookahead
in input
B T SCRATCHFILE(*) Deletes file on secondary storage
X T FINDINFILE(*) NEW INFILE, but no error if file is
not available
X T,B FINDDIRECTFILE(*) NEW DIRECTFILE, NONE if not available
for requested access
X T FINDOUTFILE(*) NEW OUTFILE, NONE if write protected
DECsystem-10 SIMULA Language Handbook, part III Page 10
0.2 SUMMARY LIST OF ROUTINES
X T FINDPRINTFILE(*) NEW PRINTFILE, NONE if write
protected
I X LASTLOC(*) Highest written line in a DIRECTFILE
I X MAXLOC(*) [NOT READY] Highest writeable line in
a DIRECTFILE
P X CLOSEOPEN(*) [NOT READY] Close and immediately
open a file
B X DOTYPEOUT(*) Resets CTRL-O bit to resume terminal
output. TRUE if file is a terminal
and the operation was successful.
4.4 CONTROLLED ERROR HANDLING
P B ENTERDEBUG(*) Transfers to SIMULA debugging system
P T ABORT(*) User program generated error
interrupt
P I FORSIM(*) Traps I/O calls from FORTRAN external
procedures
4.5 SCHEDULING AND JOB CONTROL
P B SUBMIT(*) [NOT READY] Enter file into input
batch stream
P T,I RUN(*) Runs a new program under current job
I T,B SAVE(*) Saves current main memory on a file
P T RESTORE(*) Resumes execution from save file
P I FREEZE(*) Exits to monitor, ready for SAVE
P I EXIT(*) Exits directly to monitor (I=0),
after closing files (I=1), to SIMDDT
(I=2).
4.6.1 PRIMARY MEMORY HANDLING
I I FREEBITS(*) [NOT READY] Forces garbage
collection, return maximal free area
size
4.6.2 VIRTUAL MEMORY CONTROL
B I COREGUIDE(*) [NOT READY] Sets physical guideline
B I CORELIMIT(*) [NOT READY] Sets physical limit
P XP.. SWAP(*) [NOT READY] Swaps out given module
from main store
DECsystem-10 SIMULA Language Handbook, part III Page 11
0.2 SUMMARY LIST OF ROUTINES
4.7 ENVIRONMENT ENQUIRY
I MAXINT(*) Returns largest positive INTEGER
R MAXREAL(*) Returns largest positive REAL
R MINREAL(*) [NOT READY] Returns smallest positive
REAL
L LR,LR APPROX(*) [NOT READY] Returns integer value
corresponding to numbers of bits
differing in two arguments
T IMPLEMENTATION(*) [NOT READY] CPU manufacturer and
model
T LOGINFO(*) [NOT READY] User and job id
I a DIMENSIONS(*) [NOT READY] Number of dimensions
(subscripts) of ARRAYs
4.8 PACKING INTO PARTS OF WORDS(*)
B IRLa,I,IRLCBTa,I,.. PACK Packs many variables of varying type
B IRLa,I,IRLCBTa,I,.. UNPACK Reverse of pack
4.9 MIN AND MAX
I I1,I2 IMAX(*) Max(I1,I2)
I I1,I2 IMIN(*) Min(I1,I2)
R R1,R2 RMAX(*) Max(R1,R2)
R R1,R2 RMIN(*) Min(R1,R2)
L L1,L2 LMAX(*) Max(L1,L2)
L L1,L2 LMIN(*) Min(L1,L2)
5. PROCEDURES WRITEABLE IN SIMULA
5.1 PARTITIONING OF TEXTS
T T REST(*) Subtext after POS
T T FRONT(*) Subtext before POS
T T,I FROM(*) Subtext after pos=I in T
T T,I UPTO(*) Subtext before pos=I in T
T T FRONTSTRIP(*) Subtext without leading blanks
T T GETITEM(*) Subtext = next identifier, number or
delimiter after POS
T X INITEM(*) GETITEM on INFILE [NOT READY FOR
DIRECTFILES] or DIRECTFILE
C T,I FETCHAR(*) Returns T.Sub(I,1).Getchar, null if I
out of range
P T,I,C DEPCHAR(*) T.Sub(I,1).Putchar(C), no action if
out of range.
T T,I1,I2 TSUB(*) T.Sub(I1,I2), NOTEXT where Sub gives
error
DECsystem-10 SIMULA Language Handbook, part III Page 12
0.2 SUMMARY LIST OF ROUTINES
5.2 SEARCHING AND TESTING OF TEXTS
T T,C SCANTO(*) Next occurrence of C in T
T C SKIP(*) Skips string of characters = C from
T.Pos
B T1,T2 FRONTCOMPARE(*) Does rest of T1 begin with subtext =
T2?
B T1,T2 UPCOMPARE(*) Same as FRONTCOMPARE, but upper and
lower case letters are regarded as
equal
I T1,T2 SEARCH(*) Finds first subtext = T2 from T1.Pos
I T GETTYPE [NOT READY] Does a TEXT contain REAL,
INTEGER, IDENTIFIER or what ITEM?
I T CHECKREAL(*) Checks if GETREAL can be performed
I T CHECKINT(*) Checks if GETINT can be performed
I T CHECKFRAC(*) Checks if GETFRAC can be performed
I T,I HASH Computes hash value from text in
interval [0:I-1]
C T1,T2 FINDTRIGGER(*) Next occurrence of any character of
T2 in T1
B T,I,Ta,I MENU Searches for unambiguous text in a
text array
B T,Ta,I,I,I LOOKUP Performs binary search in sorted text
array
5.3 OPERATIONS ON TEXTS
T T,T CONC2(*) Concatenation of TEXTs, two parms
T T.. CONC(*) Concatenation of variable no. of
TEXTs
B T1,T2 PUTTEXT(*) Copies value of T2 starting at T1.Pos
T T UPCASE(*) Converts to upper case
T T LOWCASE(*) Converts to lower case
T C,I MAKETEXT(*) NEW text, all I characters equal to C
T T,C COMPRESS(*) Removes given character from text
I T STARTPOS(*) Returns starting position for a
(sub)text
B T1,T2,T3 CHANGE Replaces first substring of T1 = T2,
if any, with T3. Search starts at
T1.Pos
L T SCANREAL(*) GETREAL, safe from bad data, starts
at T.Pos
I T SCANINT(*) GETINT, safe from bad data, starts at
T.Pos
I T SCANFRAC(*) GETFRAC, safe from bad data, starts
at T.Pos
I T,Ra,I GETARRAY [NOT READY] Reads from a text real
values into a REAL ARRAY
I T,Ia,I GETINTARRAY [NOT READY] Ditto INTEGER ARRAY
I T,Ra,I GETLONGARRAY [NOT READY] Ditto LONG REAL ARRAY
T T,R,C,I PUTTIME Edits a number in TIME format
DECsystem-10 SIMULA Language Handbook, part III Page 13
0.2 SUMMARY LIST OF ROUTINES
T T,R PUTFLOAT Edits a number using minimum no. of
characters
T I,I RADIX Edits 2nd parm to an item in 1st parm
base.
I I,T GETRADIX Deedits an item(T) in base I to an
integer value.
P T,T,T,T SPLIT Splits a text at given delimiter
string
I T,T,Ta,I SPLITA Splits a text and stores the parts in
a text array
I T,C,Ta,I SPLITC Same as SPLITA but with character
delimiter
I T,I,Ta,Ta SCAN Identifies keywords in a command
string.
I T,I,Ta,Ta SSCAN Version of SCAN used by GETVIS.
K I DECOM (Subclass to SAFMIN) Interprets input
command of the format
outfil.ext/switch1/switch2...
=infil.ext/switch3/switch4...
I Ta ARRLGD(*) Total length of texts in Ta + number of
elements. Used in SIMDBM.
P Ta,T,C ARRTXT(*) Put all texts of Ta in T, with delimiter = C.
Used in SIMDBM.
5.4 INPUT/OUTPUT
C X LOOKAHEAD(*) Next non-blank character readable by
INCHAR
P T,X OUTLINE(*) [NOT READY] Output TEXT on new
line(s), TEXT may be longer than
image
P T,X BREAKOUTLINE(*) [NOT READY] Output TEXT on same line,
TEXT may be longer than image
T T,X INLINE Types out a prompting question and
copies an infile image (stripped)
T T,T,T,B,T,T REQUEST Sophisticated INLINE with input
check, help etc.
P X,R,C,I OUTTIME Prints simulated time in hh:mm:ss.cc
format
P .. HISTP Prints histogram of Ia on file X
5.5 SORTING AND SUMMATION ETC.
I R ILOG Returns integer part of
10LOG(Abs(R))+1; if R = 0 return 0.
I.e. Number of integer digits if
Abs(R) >= 1 else number of leading
zeros after decimal point
I Ia,I ISUM Returns sum of an integer array
L La,I LSUM Returns sum of long real array
(almost) preserving precision
DECsystem-10 SIMULA Language Handbook, part III Page 14
0.2 SUMMARY LIST OF ROUTINES
R Ra,I RSUM Returns sum of real array
R R,R,Ra,I SIGMA2 Returns variance, mean value of a
real array
P R,R,I,R SIGMEAN Returns current variance and mean
value including new observation
P "x"a,I SORTxy Sorts a given array in ascending or
descending order.
x = T(ext), R(eal), I(nteger) or
L(ong real)
y = A(scending), D(escending) order
P Ia,I1,I2,I3 SORTDN Sorts slice Ia[1:2,I1:I1-1+N] with
respect to either or both integers in
each row.
R R,R,I SCALESTEP Adjusts approx. max and min for
diagram design
B Ia,I,I,I,B IASHIFT(*) Moves part of an integer array
leftward.
5.6 RANDOM NUMBER GENERATION ETC.
P Ia,I,I,I SCRAMBLE Random permutation of array
C Ia,N PERGEN Systematic generation of permutations
R R,R RANDOM(*) Random generator of random number
series start numbers
I UNIQUE Unique number to be used e.g. as
start random number (seed)
I I1,I2 NEXTRANDOM(*) Returns the I1:th successor to random
seed I2
5.7 SIMULA VERSIONS OF SYSTEM CLASSES
K ZIMSET SIMULA tracing version of SIMSET
K ZIMULATION SIMULA tracing version of SIMULATION
6. SWEDISH LANGUAGE TEXT PROCESSING AND INPUT/OUTPUT
B C BOKSTAV(*) Swedish version of Letter
T X INORD(*) Swedish version of INITEM
T T LITENBOKSTAV(*) Swedish version of LOWCASE
B T,I,Ta,I MENY Swedish version of MENU
T T STORBOKSTAV(*) Swedish version of UPCASE
T T TAGORD(*) Swedish version of GETITEM
I T TAGTYP [NOT READY] Swedish version of
GETTYPE
DECsystem-10 SIMULA Language Handbook, part III Page 15
0.2 SUMMARY LIST OF ROUTINES
7. UTILITIES SPECIFIC TO DECSYSTEM-10
I I1,I2 ADJPTR(*) Byte pointer I1 adjusted by I2 bytes
I I1,I2 ANDINT(*) Bitwise AND function
K ATRSTR ATR file structure
I I1,I2,I3 BITFIELD(*) Returns a bit field within I1
starting at bit I2 (0-35) with length
Abs(I3) (1-36) (I3 negative gives
sign extension)
B I1,I2 BITGET(*) BITGET:=I1.bit(36-I2)=1
P I1,I2,B BITPUT(*) I1.bit(36-I2):=IF B THEN 1 ELSE 0
I I1,I2,I3 BOOLFUNC(*) One (0<=I1<=15) of 16 Boolean
functions of I2,I3 (bitwise, like
ANDINT). For any valid I1,
BOOLFUNC(I1,5,3)=I1.
B T,T CALLMIC Uses MIC to perform other tasks and
optionally return
T T,T CHECKEXTENSION Adds default extension if file spec
contains no dot and is not just of
the form DEV:
I I1,I2,I3,I4 DEPBYTE(*) I=I2 with byte at bit I3 of length I4
replaced by I1.
P X,I ECHO(*) Suppresses monitor echoing of
terminal input
I X,T FILCOP(*) Efficient copying of disk files.
Also copies creation date and
version.
K FILED Reads and writes DEC 10 line numbered
files
T X,I FILSPC Returns file specification string for
file X in format controlled by value
of I.
I I FLOKUP(*) Look up file specified by FILOP. and
LOOKUP blocks.
I I1,I2 GETTAB(*) Returns item I1 in monitor table I2
T I IDRX50(*) Interprets a 36-bit word as a
"RADIX50" symbol (code bits and
6-character identifier)
T I1,I2 IDSIXBIT(*) ASCII representation of up to 12
character identifier given in I1 and
I2 in SIXBIT (DEC 64-character code)
I R INTREA(*) "Retype" R as integer (same 36-bit
pattern)
I X JOBSTATUS(*) Get JOBSTS word for PTY or TTY
(subjob control)
I I1,I2 LOADBYTE(*) Get any byte in readable core.
I I LOADWORD(*) Get word at address (I) - any
readable word.
I I1,I2,I3 MATCH6(*) SIXBIT match of I1 to I2 according to
wildcard mask I3.
DECsystem-10 SIMULA Language Handbook, part III Page 16
0.2 SUMMARY LIST OF ROUTINES
B NUMBERED(*) Did last inimage get a line-numbered
line?
T T,I OCTAL(*) Octal representation of I, using T as
work area.
I X,R PTYCHECK(*) Any PTY (Infile X) activity in R
seconds?
X X PTYFIL(*) PTY Outfile companion to PTY Infile
X.
I X PTYINIMAGE(*) Get line of input from PTY Infile X.
Result shows how line ended.
I T,I RDX50 Converts I,T to "RADIX50"
R I REAINT(*) "Retype" I as real (same 36-bit
pattern)
B X/T,T[,B] RENAME(*) Renames or deletes first arg (file
ref/spec) to second arg (file spec).
B RESCAN(*) Makes invoking monitor command
readable by invoked program
M SIMATR Displays the information in an ATR
file
I T SIXBIT(*) First 6 characters in T converted to
sixbit word.
I I1,I2,I3 STOREBYTE(*) Stores the byte I1 using byte pointer
I2, modified (I3) bytes.
I I1,I2 STOREWORD(*) Store I1 at (I2) (abs memory
address).
I I SXRX50 RADIX50 to SIXBIT.
T T,B TMPIN(*) Reads a "TMPCOR" core file into a new
text object, and deletes the file if
B is TRUE.
T T TMPNAM(*) Creates a temporary file name like
"021PIP.TMP"
B T1,T2 TMPOUT(*) Writes a "TMPCOR" core file from T2.
Returns TRUE if successful.
I I,X,I TRMOP(*) Modifies monitor-terminal interface
I I TTYLINE Gives network node and line for tty
number I
T I1,I2 TTYNUMBER TTY number for node I1 line I2 in
network
I I1,I2,B,I3 XCALLI(*) Execute CALLI AC1,(I2). AC1=I1.
Return (I3) if CALLI does not skip
and B is TRUE, otherwise return new
value of AC1.
I T,I1,I2 WILDSIX(*) SIXBIT translation of T, recording
wildcards (? or *) in I1.
DECsystem-10 SIMULA Language Handbook, part III Page 17
1. UTILITY PACKAGES
1. UTILITY PACKAGES
--------------------
1.1 APPLICATION PACKAGES
**** SAFEIO is a package to enable a safe question-and-answer
dialogue with a conversational terminal. The programs in
the package allow you to ask the user for variables of
various SIMULA types. The user answers are checked for
correct type and for acceptance according to criteria
specified by the programmer. Help and error messages are
given. The package protects from error interrupts in
programs which may receive faulty input data from the user.
The user may save his input in a log file. This file can
later be used as input instead of the terminal. Other files
may also be used as input, intermixed with terminal input.
SAFEIO is distributed as the files SAFEIO.SIM, SAFMIN.SIM,
SIMEIO.SIM, SIMMIN.SIM, SAFEIO.RNM, SAFEIO.MAN, SAFEIO.NEW,
SAFMIN.HLP, SAFEIO.ENG, SAFEIO.SWE and SAFEIO.HLP.
Written by Mats Ohlin, Swedish National Defense Research
Institute.
The SAFEIO system offers the following facilities in a
single procedure call :
1. Issue a prompting question to the user.
2. Store the input in a simple variable.
3. Optionally accept default answers (equal to CR).
4. Check the syntax of the input.
5. Issue an appropriate message if the input is
invalid.
6. Issue an explanatory message if the user responds
with anything starting with a question mark '?'.
7. Allow the user to substitute terminal input for disk
file input. This may be done at any time a question
is to be answered.
8. Allow the user to save all accepted program input on
a disk file. This file may be used as an input file
in a subsequent run. Correspondence between saved
and current question will be checked (option by
default).
It is assumed that the user type only one item on each input
DECsystem-10 SIMULA Language Handbook, part III Page 18
1. UTILITY PACKAGES
line.
A question to the user is defined by the call:
REQUEST("prompting question", default,
***input(variable,validity), " error message if not valid",
helpproc_expression);
The parameter default is usually a text (constant)
containing a default answer value. There is a SAFEIO
attribute NODEFAULT which can be used if default answers
should be prohibited.
*** may be replaced by INT,REAL,LONGREAL,BOOL or TEXT. For
the BOOLINPUT procedure there is only one argument though,
the receiving variable.
VALIDITY is usually a Boolean expression involving VARIABLE
but may also be a call of a Boolean procedure if more
complicated validity checking is necessary. If the SAFFEIO
attribute CHECKVALIDITY is set to FALSE, no validity
checking (i.e. no evaluation of the 2nd parameter to the
***input procedure) will occur, thus speeding up SAFEIO
execution. Note, however, that this will endanger the
security of your program.
The error message is printed if VALIDITY becomes FALSE. The
prompting question will then be repeated.
HELPPROC_EXPRESSION will be evaluated each time the user
types in an answer beginning with a question mark '?'.
The SAFEIO Boolean procedure HELP (with one text parameter =
the help text) may be used for displaying a text on the
user's terminal.
If no special information should be issued the SAFEIO
procedure NOHELP may be used. (The message - "There is no
help in this case." will be issued.)
An example:
BEGIN
EXTERNAL REF (Infile) PROCEDURE findinfile;
EXTERNAL REF (Outfile) PROCEDURE findoutfile;
EXTERNAL TEXT PROCEDURE conc,upcase,frontstrip,
rest,checkextension;
EXTERNAL CHARACTER PROCEDURE fetchar,findtrigger;
EXTERNAL LONG REAL PROCEDURE scanreal;
EXTERNAL INTEGER PROCEDURE checkreal,checkint,
DECsystem-10 SIMULA Language Handbook, part III Page 19
1. UTILITY PACKAGES
scanint,ilog;
EXTERNAL BOOLEAN PROCEDURE menu;
EXTERNAL CLASS safeio;
safeio(..<name of log file for input or "">,
<"English" or "Swedish">..)
! Use "English" if you want English texts.
Use "Swedish" if you want Swedish texts. ;
BEGIN
INTEGER i; REAL x; LONG REAL y;
TEXT t; BOOLEAN b;
TEXT ARRAY table[1:4];
request("Enter integer:","14",
intinput(i,irange(i,1,20)),
outofirange(i,1,20),
help("...info issued at '?'.."));
! The default value is 14. Only positive numbers
! are allowed.;
! Note the use of the procedures IRANGE(i,low,high)
! and OUTOFIRANGE(i,low,high).
! See also Summary Chapter 5 in SAFEIO.MAN.;
request("Enter real item:",nodefault,
realinput(x,TRUE),"",nohelp);
! Default answer not allowed. Any legal real item
! is accepted since validity is TRUE.
! No help information available.;
request("Enter long real value:","E1",
longrealinput(y,y NE 0),
"? Must not be zero.",nohelp);
! Default value is 10 = E1;
request("Enter yes or no:",nodefault,
boolinput(b),"",nohelp);
! Note that procedure boolinput has only one
! parameter.;
table[1]:- Copy("START");
table[2]:- Copy("END");
table[3]:- Copy("GO");
table[4]:- Copy("GOTO");
request("Enter command:",nodefault,
textinput(t,menu(t,i,table,4)),
DECsystem-10 SIMULA Language Handbook, part III Page 20
1. UTILITY PACKAGES
commandmessage(index),commandhelp(table,4));
! The user may use an abbreviated form when no
! ambiguity exists.
! (Exact matches are always considered correct.)
! The variable i will return the table index.
! The length of the table (4) must also be supplied.
! Note that the table must contain upper case
! letters only.
! The procedure MENU resides in LIBSIM and checks
! for correspondence between T and TABLE.;
! The text procedure COMMANDMESSAGE will tell the
! user if his (illegal) command was either
! Unknown or Ambiguous.
! A simple text request: ;
request("Enter A or B:","A",
textinput(t,t = "A" OR t = "B" OR
t = "a" OR t = "b"),
"? Answer A or B.",nohelp);
! The user may define his own boolean procedure for
! input validation if more complicated tests are
! necessary.;
GO TO start; ! Will restart from SAFEIO prefix;
! START is a SAFEIO label located
! just in front of INNER.;
! If the label EOF exists,
! End-of-file on SYSIN (=^Z)
! will jump to this label. If EOF does not not exist
! in the user program, the SAFEIO block will
! terminate through an internal SAFEIO jump.
! NOTE! Once Sysin.Endfile is TRUE, there can be no
! more input on Sysin! This mechanism will only
! work for blocks prefixed by SAFEIO
! (i.e. NOT when using NEW SAFEI(O)).;
END of SAFEIO block;
END of program;
On receiving any SAFEIO question on the terminal
the user may input one of the SAFEIO commands:
? to get help information.
DECsystem-10 SIMULA Language Handbook, part III Page 21
1. UTILITY PACKAGES
! FOLLOWED by:
* to change the switch: Display-prompting-question.
/ to change the switch: Display-default-value.
= to change the switch: Display-input (+ the *- and
/-switches).
[ to change the switch: Trace (file messages).
+ to close and reopen current recording file in
append mode.
; to treat the line as a comment.
% to call special procedure.
& followed by input to override validity test.
<FIL.EXT to open new input file in wait mode. Default
extension =.saf
_ to continue input in nowait mode.
< to close current input file.
^ (uparrow) to close all active input files.
_FIL.EXT to open new input file in nowait mode. Default
extension =.saf
>FIL.EXT to open new recording file. Default extension
=.saf
> to close current recording file.
? to print this text.
Anything else following ! will cause current question to be
displayed.
The != command will always change the values of the switches
Display-prompting-question and Display-default-value to the
same value as the switch Display-input.
Note that the !& facility may be switched off by calling the
procedure NOOVERRIDE.
The !% facility gives the programmer the possibility to
declare his own procedure SPECIAL (with exactly that name
and without parameters) which will be called when the user
responds with !%. It is possible to interpret the
information following the !% in the procedure, thereby
expanding the power of the SAFEIO - ! commands. See
SAFEIO.MAN for further information on SAFEIO attributes.
If you are using SAFEIO via INSPECT it is not meaningful to
specify any initial recording file, since it will be closed
immediately. This is because the INNER in SAFEIO will be
passed. In order to close all possible open SAFEIO files,
end the connection block with a call of the SAFEIO procedure
closefiles. I.e. :
BEGIN EXTERNAL declarations.....;
DECsystem-10 SIMULA Language Handbook, part III Page 22
1. UTILITY PACKAGES
....
INSPECT NEW SAFEIO("","") DO ! Default
language is English ;
BEGIN .... using SAFEIO ......
closefiles;
END;
END program
By substituting the class SAFEI for SAFEIO (with the
language parameter only) the facilities numbered 1 to 6 will
still be present while the file handling facilities will
absent. The class SAFEI requires about 2/5 as much core as
SAFEIO.
By substituting SAFMIN still more SAFEIO facilities are
excluded. See SAFMIN.HLP. The size of SAFMIN is about 1/2
that of SAFEI.
The three classes SIMMIN, SIMEI and SIMEIO are identical in
all respects to SAFMIN, SAFEI and SAFEIO respectively except
that they are prefixed with SIMULATION.
**** SIMDBM Data Base Management System.
SIMBDM is a data base handling system based on the ideas in
the CODASYL DBTG proposal, but written entirely in SIMULA
for use by SIMULA programs. Facilities exist for defining
SCHEMAs (Data Base Structure Descriptions) and storing them
in the data base, for accessing the SCHEMA from the SIMULA
program and for accessing data using the SCHEMA. Data base
fields of type TEXT or ARRAY have indefinite length. New
fields can be added to existing records. Memory need not be
reserved for the largest instance of each record type. Data
base records are mapped onto CLASS instances in core. A
SIMULA program can access and use the SCHEMA, which allows
writing "data-independent" programs in SIMULA.
Restrictions: No built-in facilities exist for privacy
constraints or for solving multi-terminal access conflicts.
Written by Kalle Maekilae, Swedish National Defense Research
Institute.
DECsystem-10 SIMULA Language Handbook, part III Page 23
1. UTILITY PACKAGES
FILES ON THE DISTRIBUTION TAPE FOR SIMDBM:
SIMDBM.DOC briefly describes the other files of the system.
External classes for use with SIMULA application programs
using SIMDBM: DBMMIN.SIM, SIMDBM.SIM, DBMSET.SIM. (.ATR
and .REL files for these are part of SYS:LIBSIM).
Documentation: SIMDBM.DOC, SIMDBM.RNO, SIMDBM.HLP,
NEWDBM.RNO.
General purpose program (FETCH) for conversational queries
to data bases: FETCH1.SIM, FETCH2.SIM, FETCH.SIM,
FETCH.RNO, HMESS.DMP, FETCH.EXE, DBLOAD.SIM, DBDUMP.SIM.
Loading of SIMDBM-data bases from a sequential file:
LOAD.SIM, LOAD.HLP, DBLOAD.SIM, DBDUMP.SIM.
Text editing of SIMULA direct access files from a terminal:
DIRED.SIM, DIRED.HLP.
Entering a SCHEMA (Data Base Structure Specification) into a
data base: SPEC.SIM, SPEC.EXE.
Preprocessor, producing SIMULA procedures for loading
records from a SIMDBM data base: PREP2.SIM.
Preprocessor, producing SIMULA class with internal
representation of records from a SIMDBM data base:
PREP1.SIM.
**** STORE is a simple text oriented data base handler providing
two main procedures PUTMESSAGE and GETMESSAGE. PUTMESSAGE
stores a message under a key in a direct access file, and
GETMESSAGE returns the message stored under a given key.
Both key and message can be text strings of arbitrary
length. STORE is distributed as the files STORE.SIM,
STORE.RNO, STORE.HLP and STOREU.SIM. STORE.RNO is STORE.HLP
in RUNOFF format. STOREU.SIM is an application example
which also uses the SAFEIO package.
Written by Jacob Palme, Swedish National Defence Research
Institute.
DECsystem-10 SIMULA Language Handbook, part III Page 24
1. UTILITY PACKAGES
**** SELECT is a SIMULA class to facilitate searching of TEXT
strings or files applying Boolean conditions like
"(SIMULA+ALGOL)&(DEC+DIGITAL)"
The Boolean condition is first translated into a formula
tree. This formula tree can then be applied to any number
of TEXTs, and TRUE will be returned for those TEXTs
containing words satisfying the Boolean condition.
Files: SELECT.SIM, SELECT.RNH and SELECT.HLP. In LIBSIM,
SELECT.REL and SELECT.ATR can be available.
Written by Jacob Palme, Swedish National Defence Research
Institute.
**** GPSSS is a package which converts SIMULA (by additions
within the language) into a programming language very
similar to GPSS.
GPSS is a well-known system for simulating systems of queues
and work stations and objects moving from work station to
work station. GPSSS provides the same facilities in SIMULA,
including the built-in standard statistics, in a way which
is very similar to GPSS. The advantage with using GPSSS may
be that you can easier go outside the GPSS boundaries, since
SIMULA is a much more general-purpose language.
GPSSS may also be useful for introducing SIMULA to people
who know GPSS.
GPSSS was originally written by Professor Jean G. Vaucher
at the Universit'e de Montr'eal, and was converted to
DECsystem-10 by Joakim Bose.
GPSSST is an extended version of GPSSS with much more
tracing facilities.
Further information, see GPSSS.MAN.
GPSSS is distributed on the SIMULA distribution tape in the
following files: GPSSS.SIM, GPSSST.SIM, GPSSS.ATR,
GPSSST.ATR, GPSSS.REL, GPSSST.REL. An english-language
manual is available in the files GPSSS.RNM, GPSSS.MAN. The
tape also includes IBM SIMULA versions as GPSSS.IBM and
GPSSST.IBM. A swedish language version of the manual is
included as the files GPSSWE.RNM and GPSSWE.MAN.
DECsystem-10 SIMULA Language Handbook, part III Page 25
1. UTILITY PACKAGES
**** FIGURE is a basic graphic package for handling TEKTRONIX
graphic terminals in SIMULA. FIGURE is described in the
help file FIGURE.HLP.
Written by Aake Blomberg, Swedish National Defence Research
Institute.
**** VISTA is a package to get full control of an alphanumerical
display terminal. You can move the cursor freely around the
screen, and produce programs for e.g.:
> Moving pictures,
> Continuously changing tables,
> Form-fill-in method of data entry with immediate validity
checking of each field,
> Table-fill-in method of data entry with immediate validity
checking of each field.
VISTA will not work on all kinds of alpahnumeric display
terminals. At the time of this writing, the package works
on the following terminal types:
Infoton VISTA, VISTAR SATTELITE and I 200, DEC VT52, TEC
MINITEC and TELE-TEC, BEEHIVE B100, MINIBEE, TANDBERG TDV
2000, Datamedia ELITE 1520 , 2520, 3025, CDC 713-10, Volker
404.
Work is going on to modify it for other terminals. In many
cases, the user can in a simple way describe a new kind of
terminal by a few keystrokes when running the package.
See the VISTA.MAN handbook for current information on which
terminals can be handled by the package.
VISTA.PAP contains a textual description of what can be done
with the VISTA package, VISTA.MAN(VISTA.RNM) contains a
programmers manual to the package.
Files: VISTA.SIM, FORM.SIM, CAT.SIM, SHIP.SIM, QSIM.SIM,
VIDED.SIM, TERMTY.SIM, GETVIS.SIM, VIDED.MAN, VIDED.HLP,
FORMT.SIM, VISTA.RNM, VISTA.RNH, VISTA.PAP.
Written by Jacob Palme, Swedish National Defence Research
Institute.
DECsystem-10 SIMULA Language Handbook, part III Page 26
1. UTILITY PACKAGES
**** FORM package for formula input using VISTA, see above.
**** GETVIS procedure for finding out what kind of terminal the
user has from SWITCH.INI, TMP:TRM, command line or user
input, before calling VISTA; see above.
**** DAHELP
The DAHELP class may be used in order to save core in
application programs when the HELP text segments are very
long and/or numerous.
If you prepare a number of sequential files with names equal
to the respective keywords, the MAKHLP program may be used
in order to create a DAHELP direct access file. This file
could then be used by the DAHELP class in order to display
any of the included (sub)files on the terminal (i.e.
Sysout). It is also possible to make DAHELP list all
entries (keywords) in the DAHELP file.
Written by Mats Ohlin, Swedish National Defense Research
Institute. Files: DAHELP.SIM, DAHELP.HLP, and in LIBSIM
DAHELP.ATR, DAHELP.REL.
**** SQHELP is a program to simplify the provision of a help
facility in a conversational program, where different parts
of the help file may be printed via different help requests
in the program.
SQHELP makes a sequential search of the help file, and
displays all pages containing a certain word. Compared to
DAHELP, this has the following advantages and disadvantages:
> The help file can be a sequential file, readable also via
the monitor HELP command and requiring less core than direct
access files.
> The user can supply key words to guide the help file search.
> Much slower than DAHELP, not suitable for very large help
files.
> The search is governed by words contained in the help file
text, not by the title of the help file segments.
Files: SQHELP.SIM, SQHELP.RNH and SQHELP.HLP. LIBSIM can
contain SQHELP.ATR and SQHELP.REL.
DECsystem-10 SIMULA Language Handbook, part III Page 27
1. UTILITY PACKAGES
Written by Jacob Palme and Mats Ohlin, Swedish National
Defence Research Institute.
1.2 DEMONSTRATION PROGRAMS
The save set SIMDEM on the SIMULA distribution tape contains
some simple SIMULA programs which can be used to demonstrate
the ideas of the SIMULA programming language. (Written by
Jacob Palme.)
The programs are:
QASETE, which is a very simple question-answering system
accepting statements like "BOOK IS DOCUMENT. DOCUMENT IS
OBJECT." and being able to answer questions like "IS BOOK
OBJECT?".
STAT1E, which is a very simple simulation program of the
transport operation between a harbour, a store and a
factory. The simulation program lacks all tracing and
result output.
STAT2E is the same simulation program as in STAT1E, but with
tracing and result output added without obscuring the logic
of the simulation program. The intention is to illustrate
the power of the SIMULA language for this kind of structured
programming.
DDTDEM which is a simple program to demonstrate SIMDDT.
STAT1E can also be used to demonstrate SIMDDT.
CAT, SHIP and QSIM are simple demonstrations of simulations
using the VISTA package for "moving pictures" on
alphanumeric display terminals. CAT is a cat-and-mouse game
on the screen, SHIP a troup transport simulation, QSIM a
simulation of a doctor's waiting room.
FORMT and TABLE are simple demonstrations of the form
methods for data collection, based on the VISTA package.
DECsystem-10 SIMULA Language Handbook, part III Page 28
2. SIMULA SOURCE PROGRAM CONVERSION PROGRAMS
2. SIMULA SOURCE PROGRAM CONVERSION PROGRAMS
---------------------------------------------
**** SIMED converts SIMULA source programs to a more readable
format. The block structure is indicated by indentation and
reserved words are (optionally) capitalized to distinguish
them from other identifiers. SIMED is described further in
the DECsystem-10 SIMULA Language Handbook Part II Appendix
L. SIMED is distributed as four files, SIMED.SIM, SIMED.HLP
and SIMED.EXE.
Written by Mats Ohlin, Swedish National Defence Research
Institute.
**** SIMSTR [NOT READY]
Documents a SIMULA program by extracting only structural
lines from the program.
**** IBMSIM converts SIMULA source programs from IBM 360/370 to
DECsystem-10. The program is described in Appendix M.1 of
the DECsystem-10 SIMULA Language Handbook Part II. IBMSIM
is distributed as three files, IBMSIM.SIM, IBMSIM.HLP and
IBMSIM.EXE.
Written by Mats Ohlin, Swedish National Defence Research
Institute.
**** SIMIBM converts SIMULA source programs from DECsystem-10 to
IBM 360/370. The program is described in Appendix M.2 of
the DECsystem-10 SIMULA Language Handbook Part II. SIMIBM
is distributed as three files, SIMIBM.SIM, SIMIBM.HLP and
SIMIBM.EXE.
Written by Mats Ohlin, Swedish National Defence Research
Institute.
**** CDCSIM converts SIMULA source programs from CDC to
DECsystem-10. The program is described in Appendix M.3 of
the DECsystem-10 SIMULA Language Handbook Part II. CDCSIM
is distributed as two files, CDCSIM.SIM and CDCSIM.EXE.
Originally produced at the Norwegian Computing Center,
modified by Lars Enderin and Jacob Palme at the Swedish
National Defence Research Institute.
**** SIMEXP merges a SIMULA source program and the external
modules it refers to into a single segment. This is
sometimes necessary when moving SIMULA programs from the
DECsystem-10 to other computers. SIMEXP is described in
SIMEXP.HLP and distributed as SIMEXP.SIM and SIMEXP.EXE .
Written by Sten Perers, Swedish National Defence Research
Institute.
DECsystem-10 SIMULA Language Handbook, part III Page 29
2. SIMULA SOURCE PROGRAM CONVERSION PROGRAMS
**** FQC measures the frequency with which the statements in a
SIMULA program are executed. FQC is described in Appendix J
in the DECsystem-10 SIMULA Language Handbook Part II. FQC
is distributed as FQCRED.SIM, FQCRED.EXE, FQCLST.SIM,
FQCLST.EXE, FQC.HLP.
Written by Stefan Arnborg, modified by Dag Gruneau and Mats
Ohlin, Swedish National Defence Research Institute.
DECsystem-10 SIMULA Language Handbook, part III Page 30
3. DIRECTFILE HANDLING PROGRAMS
3. DIRECTFILE HANDLING PROGRAMS
--------------------------------
**** DIRED program
A general editor for DIRECTFILEs.
Files: DIRED.SIM, DIRED.SAV, DIRED.HLP.
Written by Kalle Maekilae, Swedish National Defense Research
Institute.
**** MAKEDF program
Converts a sequential file into a DIRECTFILE and vice versa.
If the sequential file is line numbered, the line numbers
are used as locations for the DIRECTFILE.
Files on the distribution tape: MAKEDF.SIM, MAKEDF.EXE,
MAKEDF.HLP.
Written by Jacob Palme, Swedish National Defense Research
Institute.
**** FETCH program
FETCH is part of the SIMDBM package. FETCH allows you to
access the data base directly from a terminal, without
running any programs. Changes to the SCHEMA must however be
made with the program SPEC. See further the SIMDBM
documentation.
Written by: Kalle Maekilae, Swedish National Defense
Research Institute.
**** MAKHLP program
The MAKHLP program modifies or creates a DAHELP Direct
Access Help file by appending named sequential file
references.
MAKHLP can not delete any parts of the Direct Access file.
For such purposes - reconstruct the file from scratch or use
the DIRED program to patch up the file according to DAHELP
format (imagesize:73). See DAHELP.HLP for more information.
Files on the distribution tape: MAKHLP.SAV, MAKHLP.SIM,
MAKHLP.HLP.
DECsystem-10 SIMULA Language Handbook, part III Page 31
4. PROCEDURES NOT WRITEABLE IN SIMULA
4. PROCEDURES NOT WRITEABLE IN SIMULA
----------------------------------
NOTE: Some of these routines are not yet written. See the
list in chapter 0.2, which indicates which routines are
ready.
The source code for these routines can usually be found in
the large files LIBSM1.PAC and LIBSM2.PAC. Unpack the
individual files with the program FILPAC.SAV. FILPAC places
the unpacked files on DSKD. If you want the files on
another file structure, say DSKB, do .ASSIGN DSKB DSKD
before running FILPAC.
4.1 TIME AND DATE
**** TEXT PROCEDURE TODAY
Returns a reference to a text object of length 10 with
contents:
"yyyy-mm-nn"
where yyyy is year, mm is month(in digits 01-12), nn is day
(in digits 01-31). This is the internationally standardized
format for dates.
**** INTEGER PROCEDURE dayno
Integer procedure DAYNO returns the ordinal day number in
current year.
EXTERNAL PROCEDURE required: TEXT PROCEDURE today;
BEGIN
INTEGER day,month,year; TEXT t;
t:- today;
month:= t.Sub(6,2).Getint;
day:= 30*(month-1) + (4*month-7)//6;
IF month > 4 THEN day:= day - 1 ELSE
IF month = 2 THEN day:= day + 1;
IF month > 2 THEN
BEGIN year:= t.Getint;
day:= IF Mod(year,400) = 0 THEN day - 1 ELSE
day - Sign(Mod(year,4));
END After February;
dayno:= day + t.Sub(9,2).Getint;
END of dayno;
DECsystem-10 SIMULA Language Handbook, part III Page 32
4.1 TIME AND DATE
**** TEXT PROCEDURE DAYTIME
Returns a reference to a new text object of length 8 with
contents:
"hh:mm:ss"
where hh is hours
mm is minutes
ss is seconds.
at the time of the call.
This is the internationally standardized format for writing
time-of-day.
**** PROCEDURE TIMELIMIT(maxtime); REAL maxtime;
The execution will be interrupted when the allotted time is
up. The parameter is the time limit in seconds. If the
argument is non-positive, the effect will be as if TIMELIMIT
was never called.
**** REAL PROCEDURE CPTIME
Returns total CPU time spent since the beginning of the
SIMULA program execution, expressed in seconds.
**** REAL PROCEDURE CLOCKTIME
Returned value is time of day in seconds, i.e. the absolute
difference between the results of two successive calls is
the time which elapsed between the calls (except when
passing midnight).
DECsystem-10 SIMULA Language Handbook, part III Page 33
4.2 REAL-TIME FOR MULTI-TERMINAL SIMULTANEOUS I/O.
4.2 REAL-TIME FOR MULTI-TERMINAL SIMULTANEOUS I/O.
NOTE
These procedures will usually not work on the
DECsystem-20 under the TOPS-20 monitor.
The goal of this is to allow one program to talk
simultaneously to several conversational terminals and other
on-going processes (jobs) in the computer. A break in one
such dialouge should not inhibit the conversation with the
other terminals and processes.
Chapter 4.2.1 below describes three simple assembly
procedures which you can use if you want to write your own
scheduling of the parallel processes for handling the
external devices.
Chapter 4.2.2 and appendix A describe a simple scheduler for
realtime applications written in SIMULA. The scheduler
allows you to use SIMULA processes, one for each external
device.
4.2.1 BASIC ASSEMBLY PROCEDURES FOR REAL TIME
**** BOOLEAN PROCEDURE INPUTCHECK(inputfile);
REF (infile) inputfile;
The parameter infile is connected to an external device or
another job process. INPUTCHECK will return TRUE if an
INIMAGE can be made on the INFILE without delay, that is if
data for the INIMAGE is already available. If the external
device has no pending input, INPUTCHECK will return FALSE.
INPUTCHECK will also return FALSE if the parameter is NONE,
refers to a closed file or refers to a file where ENDFILE is
TRUE. Supported devices are those which can be used from
SIMULA. DSK is regarded to be ready for input without
delay. (WARNING: INPUTCHECK may not work when heavy
transmission of data is going on to the same terminal. In
that case, use of the TTYCHECK procedure may be a better
alternative.) TTY and PTY are the primary devices
considered. See PTYCHECK etc in section 7 of this handbook.
NOTE: Will not work on DECsystem-20!
DECsystem-10 SIMULA Language Handbook, part III Page 34
4.2 REAL-TIME FOR MULTI-TERMINAL SIMULTANEOUS I/O.
**** PROCEDURE SLEEP(sleepsec); REAL sleepsec;
This procedure takes one parameter of type REAL and will
stop the execution for a real time interval of at least this
duration. Resolution is 0.001 on a DECsystem-10.
A special version is needed on the DECsystem-20 (uses DISMS
JSYS).
**** INTEGER PROCEDURE INPUTWAIT(filearray,maxtime);
REF (infile) ARRAY filearray; REAL maxtime;
NOTE: This procedure will not work on DECsystem-20!
This procedure stops the executing SIMULA program until
INPUTCHECK would be TRUE for at least one of the parameter
files, or until MAXTIME seconds have elapsed. MAXTIME = 0
indicates no time limit on the wait. Some of the array
elements may be NONE. Whenever INPUTCHECK would be TRUE for
one of these files, execution of the SIMULA program
continues. If INPUTCHECK is already TRUE for one of the
files when INPUTWAIT is called, then INPUTWAIT will return
immediately to the calling program. The procedure returns
an integer which is the index of a file in the parameter
array from which input has been received, not necessarily
the first one if input has been received from more than one
of the input files. INPUTWAIT disregards those array
elements which are NONE or which refer to closed files, and
files with ENDFILE = TRUE. If all the array elements are
disregarded in this way, then inputwait does not stop
execution but returns an integer which is 1 less than the
lower bound of the parameter array. If the wait was
interrupted becuse of the time limit maxtime, then an
integer which is 2 less than the lower bound of the
parameter array is returned.
Special feature: If the first file to wake up the program
is a PTY file, and it has no output ready (ready for
Inimage), but it can accept input (i.e. output on the
corresponding Outfile), the returned value is the array
index as above + 2^18.
DECsystem-10 SIMULA Language Handbook, part III Page 35
4.2 REAL-TIME FOR MULTI-TERMINAL SIMULTANEOUS I/O.
4.2.2 REALTIME - A SCHEDULER FOR TERMINAL PROCESSES
REALTIME is a separately compiled CLASS written in SIMULA as
a subclass to SIMULATION. REALTIME is based on the idea
that you have one SIMULA process connected to each
conversational terminal. The processes can then execute in
parallel, and the SIMULATION scheduler is used to distribute
the execution between the terminals. The CLASS REALTIME is
not only useful for simulation programs, it can also be used
for other real time applications.
A full description is included in appendix A.
REALTIME will not work on DECsystem-20.
4.3 INPUT/OUTPUT
4.3.1 ASCII-FORMATTED I/O
**** INTEGER PROCEDURE linecount(pf);
REF (Printfile) pf;
The parameter should be a reference to an open printfile
object. Result: Returns the value of the LINESPERPAGE
attribute of the printfile.
**** TEXT PROCEDURE filename(x);
REF (FILE) x;
The parameter should be a simple valid reference to an
object of an I/O class. Returns a reference to a text
object whose value is equal to the NAME parameter of the
FILE object. The resulting text value may or may not be
stripped of blanks before return.
**** CHARACTER PROCEDURE insinglechar(inf);
REF (Infile) inf;
The parameter should be a reference to an infile object
using a terminal or a disk file. Returns next input
character from the infile (after last INIMAGE) without
waiting for break character. Succeeding INIMAGE will begin
reading after the last character which has been input with
INSINGLECHAR.
Restriction: With the current release of DECsystem-10
DECsystem-10 SIMULA Language Handbook, part III Page 36
4.3.1 ASCII-FORMATTED I/O
SIMULA, INSINGLECHAR only works on the controlling terminal
or a disk file.
**** CHARACTER PROCEDURE insngl(inf);
REF (Infile) inf;
The parameter should be a reference to an infile object
using a terminal or a disk file. Returns next input
character from the infile (after last INIMAGE). Unlike
INSINGLECHAR, it works in line mode (waits for break
character). Succeeding INIMAGE will begin reading after the
last character which has been input with INSNGL.
**** CHARACTER PROCEDURE getch
GETCH is similar to INSINGLECHAR (see above) but has no
parameter and always takes input from the conversational
terminal controlling the current job.
**** BOOLEAN PROCEDURE ttycheck(timelimit); REAL timelimit;
TTYCHECK waits for an input character from the terminal and
returns with the value TRUE if a character is typed in
before TIMELIMIT seconds have elapsed, otherwise false.
TIMELIMIT should not be greater than about 60 seconds. If
TIMELIMIT is exactly zero, TTYCHECK waits indefinitely for
input. TTYCHECK does NOT read the input, only checks for
it. GETCH can be used to read the actual character when
TTYCHECK returns TRUE. Ordinary SIMULA input procedures can
also be used provided a line is typed in.
**** PROCEDURE outchr(ofile,c,n);
REF(Outfile)ofile; CHARACTER c; INTEGER n;
Outputs n identical ASCII characters to the file, which is
normally a terminal. Ofile.Image is not affected.
If n<=0, no character is output, otherwise the character c
is output n times. The buffer is used directly.
Note: Use "forceout" before terminal input after the use of
"outchr". Warning: ofile must be open, otherwise outchr
will loop!
DECsystem-10 SIMULA Language Handbook, part III Page 37
4.3.1 ASCII-FORMATTED I/O
**** PROCEDURE outstring(ofile,t);
REF(Outfile) ofile; TEXT t;
Copies the text T directly to the output buffer bypassing
Image. T is not changed. No output is forced. Output will
appear when (Break)Outimage or FORCEOUT is called. ofile ==
NONE is treated as Sysout.
Note: Use "forceout" before terminal input after the use of
"outstring".
**** PROCEDURE forceout(ofile);
REF(Outfile)ofile;
Ensures that all previous output to the TTY made with OUTCHR
or OUTSTRING reaches the TTY. Use FORCEOUT before inputting
anything from the terminal, to ensure that previous output
reaches the terminal. FORCEOUT checks if there is any
unwritten output in the buffer, so you can call it with
little cost before every input operation.
A procedure similar to FORCEOUT, but much slower, could be
written in SIMULA:
BEGIN TEXT imagecopy;
imagecopy:- ofile.image;
ofile.image:- NOTEXT;
ofile.breakoutimage;
ofile.image:- imagecopy;
END;
**** PROCEDURE read(..)
Any parameters of type integer, (long) real or character. A
reference type parameter, if used, must be a reference to an
object of class infile or directfile. A parameter may be an
array identifier of suitable type.
New values for the actual parameters are obtained one by one
from the current input file (initially SYSIN). If a
parameter is an array identifier, new values are read and
assigned for all elements of the array. A parameter which
is a reference to an open infile or directfile causes all
successive read operations (in the parameter list) to be
applied to this file.
DECsystem-10 SIMULA Language Handbook, part III Page 38
4.3.1 ASCII-FORMATTED I/O
**** PROCEDURE write(..)
Any parameters of type integer, (long) real, character or
text. Constants and arrays are also allowed. A reference
type parameter, if used, must be a simple reference to an
object of class outfile, printfile or directfile.
Values of actual parameters are output one by one on the
current output file (initially SYSOUT). The output formats
for the respective values are
this machine plus 1
INTEGER i outint(i,n) where n is the number of digits
printed for the largest possible integer on
this machine plus 1
REAL x print x in flexible format according to:
if x = 0 then outfix(x,0,w) else
if abs(x) >= 10^d then outreal(x,d,w) else
if abs(x) >= 10^(-e) then
outfix(x,d-ilog(x)+(if abs(x) >= 1 then 0
else -1),w)
else outreal(x,d,w);
where d is number of significant digits, e
is number of positions required for the
exponent part and w := e + d + 2 (sign and
dot positions).
LONG REAL z same as for real but for long real
significance
CHARACTER c outchar(c)
TEXT t outtext(t)
If the actual parameter is an array identifier, the values
of all its elements are output. A parameter which is a
reference to an open printfile, outfile or directfile,
causes all successive output operations to be applied to
this file. Each call on WRITE ends with a call on OUTIMAGE
which also is called implicitly if the image is filled
before all parameters are processed. The final OUTIMAGE
concerns every file mentioned; thus OUTIMAGE (for the
previous file) is called when a new file reference is given
as well as at the end of the parameter list.
DECsystem-10 SIMULA Language Handbook, part III Page 39
4.3.2 UNFORMATTED (BINARY) I/O.
4.3.2 UNFORMATTED (BINARY) I/O.
*********************** WARNING **************************
* Use of the procedures described in this section may make *
* your programs difficult to move to another SIMULA system.*
************************************************************
Unformatted I/O is a tricky problem because we have many
diverse requirements to put together, if possible, in one
construct.
> Very fast and efficient input and output of much data.
> Simple input and output procedures, taking whole texts,
arrays, or objects at a time.
> General purpose input and output procedures, to be able to
read and write easily any kind of file, e.g. a file
containing line numbered lines, an object program file, a
file which was produced by FORTRAN binary output, a disk
directory file etc. etc.
Two procedures INPUT and OUTPUT have been written.
The first parameter to INPUT is a reference to an object of
the CLASS infile or directfile, the first argument to OUTPUT
is a reference to an object of the CLASS outfile or
directfile.
Both these procedures can take any number of additional
parameters of any SIMULA type except label, switch or
procedure. The action of OUTPUT is:
**** INTEGER PROCEDURE OUTPUT
OUTPUT returns the number of characters (over)written in the
file. (Including any output produced which is not directly
related to the parameters, e.g. null characters, null words
etc. IF OUTPUT is made on a DIRECTFILE, it may be important
for the user to know how many lines on the file that are
covered by one or several calls to OUTPUT. He can do this
by dividing the sum of the INTEGERs returned from OUTPUT
with (image.length+2) of the directfile. Such a program
will be machine-independent since OUTPUT returns number of
characters.
For parameters of type INTEGER, [LONG]REAL or BOOLEAN: the
value of the parameter is output in such a way that it can
be read by a FORTRAN program. One word (36 bits on the
DECsystem-10) is output. Two words (72 bits) are output for
LONG REALs.
DECsystem-10 SIMULA Language Handbook, part III Page 40
4.3.2 UNFORMATTED (BINARY) I/O.
For parameter of type CHARACTER: The internal value is
output. SIMULA systems which pack CHARACTERs in words will
output only the character byte, systems which store
CHARACTERs in full words will output the full word.
For parameters of type TEXT: First the LENGTH of the TEXT
is output in the same way as if it had been given as an
explicit INTEGER parameter to OUTPUT. Then the characters
of the text value are output in internal implementation
dependent format (ASCII-7-bit code packed 5 characters to a
word on the DECsystem-10). If the characters are packed (as
they are on the DECsystem-10) and the last output word is
not full, then it is filled with NULL characters. The
output TEXT value may n o t be preceded by NULL characters
to permit faster output of subtexts. NOTEXT is output as
only the integer LENGTH(=0), and nothing more.
All characters which can be created with the procedure CHAR
can be part of a TEXT which is written by OUTPUT and read by
INPUT, and they should all be returned unchanged after
OUTPUT and a corresponding INPUT.
Note that for subtexts, only the subtext part of the value
is output. If several texts have a common part, the value
is still output completely for each text.
For parameters of kind ARRAY: Each element of the ARRAY is
output just as if it had been a non-array parameter to
OUTPUT. (Even for REF-arrays.) The dimensions and bounds of
the ARRAY are not output.
For parameters of type REF:
All value attributes of the referred object except REF and
REF-array attributes are output just as if these attributes
had been parameters to OUTPUT. REF or REF ARRAY attributes
are not output at all.
OUTPUT may, in an implementation dependent way, output other
descriptive data about the structure of the CLASS to ensure
correct input by INPUT as described below.
If the argument to OUTPUT has the value NONE, then some kind
of indication about this is output.
The order in which the attributes are output is
implementation dependent, and not necessarily the same as
the order in which they are declared in the SIMULA source
program.
Important: If the parameter to OUTPUT is qualified by a
SUPERCLASS (an outer class) of the actual object to which it
DECsystem-10 SIMULA Language Handbook, part III Page 41
4.3.2 UNFORMATTED (BINARY) I/O.
refers, then only attributes of the SUPERCLASS are output.
**** INTEGER PROCEDURE INPUT
INPUT works analogously with OUTPUT so that anything written
with OUTPUT can be read with INPUT.
The INTEGER value returned by INPUT is the number of
characters read (see OUTPUT). If all the data required
could not be read because of end of file, the negated number
of characters that were read is returned. A call to INPUT
when ENDFILE is already TRUE causes an error interrupt.
For TEXT parameters, INPUT allocates a new TEXT of
appropriate length using BLANKS and reads the string into
the new TEXT. POS of the new text is set to 1.
For ARRAY parameters: INPUT works just as if INPUT had been
called once for each item in the array.
For REF parameters: INPUT may do a certain amount of
implementation dependent checking for agreement between the
data in the file and the structure of the class to which the
REF parameter refers. Those attributes of the CLASS which
were output with OUTPUT will then be read in. TEXTs will be
allocated with POS = 1 and LENGTH as from the file.
INPUT will only work correctly for REF parameters if the
data at that place in the file was previously written via a
REF parameter to OUTPUT in a SIMULA program, and if the
qualification of CLASS object which was output and the
qualification of the parameter which is input from the same
place in the file agree in the following respects:
1. The order and type of all attributes which are output
and later input agree.
2. An attribute which was a parameter to the CLASS in
OUTPUT must also be a parameter in INPUT.
3. If the CLASS has superclasses, then the attributes must
be distributed between the subclasses in the same way.
4. The number and bounds of the dimensions of ARRAY
attributes must agree.
5. If the argument to OUTPUT had the value NONE, then the
corresponding argument to INPUT must also have the value
NONE.
DECsystem-10 SIMULA Language Handbook, part III Page 42
4.3.2 UNFORMATTED (BINARY) I/O.
However, even if the requirements above are not fulfilled,
INPUT is still protected from changing any data in core
except attributes of the CLASS of type INTEGER, REAL, LONG
REAL, CHARACTER or TEXT, which are accessible to the
programmer.
The following characteristics need n o t agree between the
CLASS in INPUT and the CLASS in OUTPUT:
1. The SIMULA source program identifier names of the
attributes.
2. Number, type, qualification etc. of attributes which
were not output with OUTPUT (e.g. REF or PROCEDURE
attributes).
3. The executable code in the CLASS.
4. The structure of such subclasses which were not output
with OUTPUT because of the qualification of the REF
parameter to OUTPUT.
Note that the data OUTPUT with an OUTPUT statements does not
constitute any "logical block". It is therefore possible to
output certain data with "OUTPUT(file,a,b);" and then input
the data with "INPUT(file,a); INPUT(file,b);".
The organisation of files produced by OUTPUT and read by
INPUT should, if reasonably possible, be such that FORTRAN
programs on the same computer can read and write such files.
**** INTEGER PROCEDURE PUTSIZE
To help the programmer avoid overwriting previous
information in a directfile there is an auxiliary INTEGER
PROCEDURE PUTSIZE with the same kind of parameters as
OUTPUT, except for the first parameter (giving the output
file) which need not be given to PUTSIZE. PUTSIZE will
return the same integer as would be returned by OUTPUT if
called with an identical parameter list.
**** BOOLEAN PROCEDURE BYPASS
BOOLEAN PROCEDURE BYPASS(fileref,x) will move the internal
buffer pointer x characters. X may be negative if fileref
is a directfile. If end of file is encountered for an
infile, BYPASS should return TRUE the first time; if called
again a run time error should occur. The first parameter
may refer to any kind of file except a printfile.
DECsystem-10 SIMULA Language Handbook, part III Page 43
4.3.2 UNFORMATTED (BINARY) I/O.
There is a further BOOLEAN PROCEDURE LOOK which takes two
parameters, the first a reference to an infile object, the
second of type INTEGER, [LONG] REAL or CHARACTER. LOOK
examines the next word in the input buffer without reading
it. Array parameters are not allowed. Should return TRUE
if end of file is encountered; run time error for the next
call.
LOOK might for example be used to check if a line is line
numbered before reading the line.
COMBINING OUTPUT AND INPUT WITH INIMAGE AND OUTIMAGE.
Future versions of DECsystem-10 SIMULA may, because of
standardization work with other SIMULA systems, forbid the
combination of OUTIMAGE and INIMAGE with OUTPUT and INPUT on
the same file. The user is strongly recommended not to use
such a combination.
At your own risk, OUTPUT and INPUT can be combined with
OUTIMAGE and INIMAGE on the same file. The file may be
padded with NULLs after OUTIMAGE to a word boundary before
the data written by OUTPUT. OUTPUT and INPUT do not work
through the IMAGE of the file, which is thus not touched in
any way.
For DIRECTFILES, OUTPUT and INPUT will not change the value
of LOC. The first OUTPUT or INPUT after an INIMAGE,
OUTIMAGE or LOCATE will start at the indicated location.
Successive OUTPUTs or INPUTs will start at the place in the
file where the previous OUTPUT or INPUT stopped. A call to
LOCATE preceding OUTPUT or INPUT will cause the OUTPUT/INPUT
operation to start at the indicated position. Note that
this means that an OUTIMAGE immediately after an OUTPUT may
overwrite what was output with the OUTPUT. (Since LOC was
not changed). OUTPUT may overwrite several lines in the
directfile.
OUTPUT and INPUT are allowed on INFILEs, OUTFILEs and
DIRECTFILEs but not on PRINTFILEs.
WARNING!!!! The procedures above have not been approved by
the SIMULA DEVELOPMENT GROUP. If your programs rely on
them, they may be difficult to transfer to SIMULA systems on
other computers than the DECsystem-10. This is especially
true if you combine OUTIMAGE and INIMAGE with OUTPUT and
INPUT on the same file.
DECsystem-10 SIMULA Language Handbook, part III Page 44
4.3.3 FILE HANDLING
4.3.3 FILE HANDLING
**** REF (infile) PROCEDURE FINDINFILE(filespec);
VALUE filespec; TEXT filespec;
**** REF (directfile) PROCEDURE FINDDIRECTFILE(filespec,update);
VALUE filespec, update;
TEXT filespec; BOOLEAN update;
**** REF (outfile) PROCEDURE FINDOUTFILE(filespec);
VALUE filespec;
**** REF (printfile) PROCEDURE FINDPRINTFILE(filespec);
VALUE filespec;
The four procedures findinfile, finddirectfile, findoutfile
and findprintfile are rather similar to the statements NEW
infile, NEW directfile, NEW outfile, NEW printfile. The
difference is that the value NONE is returned, if such a
file cannot be opened. For directfiles, if the input
parameter update is TRUE, NONE is also returned if such a
file cannot be opened for output.
Reasons why a file cannot be opened may be:
> That an infile does not exist.
> That the file exists, but the file protection system of the
computer does not allow opening.
> For a directfile with update=TRUE or for an outfile: That
you cannot open the file because someone else is updating
it.
If possible, the indicated file is reserved for the user so
that "a:- finddirectfile(....,TRUE); a.open;" will not fail
because someone else opens the file between the two
procedure calls in the example.
Example of use:
FOR D:- finddirectfile("....",TRUE)
WHILE D == NONE DO sleep(10);
Will sleep until the directfile is updateable.
**** BOOLEAN PROCEDURE SCRATCHFILE(filespec);
VALUE filespec; TEXT filespec;
If the file indicated by filespec exists and the program is
allowed to delete (scratch) it, the file is deleted
(scratched). The result is TRUE if a file could be deleted,
FALSE if no file could be deleted. Delete (scratch) implies
DECsystem-10 SIMULA Language Handbook, part III Page 45
4.3.3 FILE HANDLING
removing the file so that it becomes inaccessible to this
and other programs on the computer. File specifications of
the form TMP:xxx are also acceptable and refer to incore
files handled by the TMPCOR UUO on the DEC-system-10.
**** PROCEDURE CLOSEOPEN(f); REF (file) f;
Closes and opens a file again. If the file
is an infile, this will mean that input will start from the
beginning
of the file. If it is an out(print)file, then - if it was
defined
with /ACCESS:APPEND, the result up to point of calling
CLOSEOPEN, will be secured against system break-down, else -
the old information will be lost at next close.
INSPECT f DO
BEGIN TEXT t;
t:- image; close; open(t);
END;
**** BOOLEAN PROCEDURE DOTYPEOUT(tty); REF (outfile) tty;
IF tty == conversational terminal AND
the computer can restart typeout to the terminal
THEN restart this typeout, beginning with the
next outimage or breakoutimage, return TRUE;
COMMENT on the DECsystem-10, the CTRL-O bit is reset;
**** INTEGER PROCEDURE LASTLOC(df); REF (directfile) df;
Lastloc returns the highest location of any image which has
been written in the directfile during this or any previous
use of the file. Returns -1 when the directfile is not
open.
**** INTEGER PROCEDURE MAXLOC(df); REF (directfile) df;
Maxloc returns the largest integer such that
"locate(maxloc); outimage;" will not cause any error
interrupt of the program.
DECsystem-10 SIMULA Language Handbook, part III Page 46
4.4 CONTROLLED ERROR HANDLING.
4.4 CONTROLLED ERROR HANDLING.
See also the procedures SCANREAL, SCANINT and SCANFRAC in
chapter 5 of this handbook for control of bad data errors.
A proposal for advanced integrated error handling is
described in appendix B. It is not implemented and no
promise is made to ever do that.
**** PROCEDURE enterdebug(maycontinue); BOOLEAN maycontinue;
The debugging system is entered. If maycontinue is TRUE,
execution of the SIMULA program is allowed to resume after
the debugging session.
**** PROCEDURE abort(message); VALUE message; TEXT message;
BEGIN
IF message =/= NOTEXT THEN
BEGIN
outimage;
outtext("EXECUTION TERMINATED "
"DUE TO CALL OF ERROR PROCEDURE");
outimage;
outtext("MESSAGE: "); outtext(message); outimage;
END;
enterdebug(FALSE);
END;
**** PROCEDURE forsim(n); INTEGER n;
FORTRAN subroutines called from SIMULA are not allowed to do
I/O or otherwise access the FORTRAN high segment, since
SIMULA requires the SIMULA high segment. If you want to use
a FORTRAN subroutine which uses facilities in the FORTRAN
high segment, you can load your program with the FORSIM
procedure. References from FORTRAN subroutines to the
FORTRAN high segment will then be trapped by FORSIM. Note
however that FORSIM does not perform any actual I/O, so the
I/O in FORTRAN subroutines will become dummy statements.
FORSIM may also be called from FORTRAN with no parameter.
If n=0, any attempt at I/O in a FORTRAN routine
is trapped and a message is written the
first time, but execution continues.
DECsystem-10 SIMULA Language Handbook, part III Page 47
4.4 CONTROLLED ERROR HANDLING.
If n>0, execution continues n-1 times,
and then the message is typed followed by
an error entry into SIMDDT.
If n<0, execution continues, and no message
is typed.
4.5 SCHEDULING AND JOB CONTROL
**** PROCEDURE run(filespec,entrypoint);
VALUE filespec; TEXT filespec; INTEGER entrypoint;
FILESPEC is a text expression specifying a file containing
an executable program. RUN will transfer control to the
program specified without closing files. If the program is
not found in the user area, and device and ppn were not
given, SYS: is tried as device. On failure, RUN aborts via
HALT.
NOTE: If the RUN procedure is loaded in the high segment,
it will be wiped out. Thus only one attempt can be made.
ENTRYPOINT is an integer in the range [1,16], which
specifies where the program should be started. ENTRYPOINT =
1 is the normal value and specifies the standard entry point
which is used when the program is executed via a monitor RUN
command or the sequence GET, START. The value 2 corresponds
to the secondary entry of standard CUSP's like PIP, COMPIL,
MACRO, LINK, SIMULA. When started in this way, the CUSP
will try to read a temporary command file, which may be in
core as a so-called TMPCOR file with a three-character name,
e.g. PIP or SIM.
If the CUSP does not find the relevant TMPCOR file, it will
look for a disk file with a name of the form jjjppp.TMP,
where jjj is the decimal job number with leading zeros if
necessary, and ppp is the three-character name. Examples:
007PIP.TMP, 129SIM.TMP.
Filenames with the required format can be generated by the
procedure TMPNAM. Normally, a CUSP command file contains
several lines specifying output and input files. The last
line can be a file specification for an executable program,
followed by "!", e.g. a LOAD or EXECUTE command will
generate a command file to the compiler whose last line is
"LINK!" specifying that LINK-10 should get control at its
secondary entry point.
DECsystem-10 SIMULA Language Handbook, part III Page 48
4.5 SCHEDULING AND JOB CONTROL
Command files may thus be generated in a SIMULA programs,
and by using SAVE and RUN together, control may be
automatically regained after executing another program.
Example: A SIMULA program could first save itself by
calling the procedure SAVE (see below), then generate a
command file to PIP, then call PIP with the procedure RUN,
then via ! in the PIP command file cause PIP to return
control to the saved SIMULA program.
**** BOOLEAN PROCEDURE submit
Parameters: One text reference or text constant.
Result: The parameter is a file reference with the same format
as the text parameter to the class INFILE. The file, if
found, is put into the input batch stream on the computer.
Returns TRUE if this could be done, FALSE otherwise.
The current job continues, independent of the new file in
the batch stream.
**** INTEGER PROCEDURE save(filespec,continueonerror);
VALUE filespec; TEXT filespec; BOOLEAN continueonerror;
The PROCEDURE save forces a garbage collection and then
outputs all dynamic memory to the file described by
filespec. The default file extension is .SAV, which is
supplied if no extension appears in filespec. If
filespec==NOTEXT, FREEZE (see below) is called from SAVE.
The second parameter, CONTINUEONERROR, is TRUE if error
messages from SAVE should be suppressed. Failure will be
indicated by the returned value, see below. If
CONTINUEONERROR is FALSE, the run time system may issue
error messages and demand user response. This may
eventually lead to successful completion if the user elects
to proceed after dealing with the error messages.
Save returns a value which indicates program status on
continuation. The possible values for the returned value
(S) are:
S<0: Some error occurred, e.g. the file specified may be
protected. The program may try to recover by giving another
file specification and calling SAVE again.
S=0: The program was continued directly, save was
successful. This value is also returned if RESTORE was
called, see below.
DECsystem-10 SIMULA Language Handbook, part III Page 49
4.5 SCHEDULING AND JOB CONTROL
1<=S<=16: The program was restarted via the RUN procedure
or an equivalent command or code sequence. The normal value
1 is assumed when the saved file is executed by a RUN
monitor command or by the RUN procedure with second
parameter = 1. Values 2-16 occur if the second parameter to
the RUN procedure is 2-16.
**** PROCEDURE restore(filespec); VALUE filespec; TEXT filespec;
The procedure RESTORE restores dynamic memory to the
contents of the file indicated by filespec. Execution is
then resumed following the point where SAVE (or FREEZE) was
called to create the file indicated by filespec. SAVE is
ignored and a warning message is issued when any file except
sysin or sysout is open.
**** WARNING ****
Sysin and sysout should both be the user terminal, since
they will be read and written from the start when
restarting, unless sysout is written in append mode (switch
/ACCESS:APPEND).
Sysin and sysout can also refer to the .CTL and .LOG file of
a batch job.
The SAVE-RESTORE facility is intended primarily for
applications with a fairly time-consuming build-up phase,
such as a large simulation, where one wants to explore
different continuations from the same branching point.
Together with the RUN procedure, which works like an
extended RESTORE, one can build a "program system"
consisting of many segments controlled almost fully by one
or several SIMULA programs. See further the RUN procedure
(above).
**** PROCEDURE freeze(returncode);
NAME returncode; INTEGER returncode;
FREEZE is a simpler and smaller version of SAVE. The
parameter RETURNCODE assumes the same values as SAVE. The
files of the program are handled as in SAVE. FREEZE does
not itself write a save file but exits to monitor level,
where the user can issue a SAVE command with an appropriate
file name. Execution can be continued by a START command,
which will give a returned value = 1 in RETURNCODE. (START
can also be given with a non-zero argument, but this is
tricky and not generally recommended, since it is impossible
to guard against wild results). The saved file can be
handled as explained above. If no save file is wanted, the
user simply issues a CONTINUE command, giving the result
RETURNCODE = 0, and execution continues.
DECsystem-10 SIMULA Language Handbook, part III Page 50
4.5 SCHEDULING AND JOB CONTROL
**** PROCEDURE exit(n);
INTEGER n;
EXIT(0) terminates the program immediately, exactly as if
the user had typed CONTROL-C (twice). Useful if you want
your program to terminate with some short message like
"Thank you." instead of the standard message "End of
execution...". Note that you have to close your files
(except TTY files) explicitly, since no checking of open
files will occur. EXIT(0) is therefore also useful where
the program is to terminate without closing all files - not
invoking the standard SIMDDT action. Note that if EXIT(0)
is called just before last END, CONTINUE will cause the
standard termination message "End of execution.." to appear.
One additional CONTINUE will invoke SIMDDT as usual.
EXIT(1) will terminate execution just as if the final END of
the program had been passed. The standard message will
appear.
EXIT(2) will invoke SIMDDT in debug mode, and the user is
free to do anything SIMDDT permits, including issuing the
EXIT command to terminate execution. C.f. procedure
ENTERDEBUG.
Other values of n are reserved for possible extensions.
DECsystem-10 SIMULA Language Handbook, part III Page 51
4.6 MEMORY HANDLING
4.6 MEMORY HANDLING [Not ready]
This section concerns procedures which are not implemented
with the current release of DECsystem-10 SIMULA. We may
perhaps never implement them.
4.6.1 PRIMARY MEMORY HANDLING
EXTERNAL INTEGER PROCEDURE freebits
Parameters: One integer parameter. Negative parameter means no
garbage collection, zero or positive parameters means
garbage collection. If the parameter is positive, then it
indicates the amount of core (in bits) that will be assigned
to the job after the forced garbage collection, to be used
up before the next automatic garbage collection. If the
parameter is too large, no error is caused, the system will
then wait as long as technically possible before the next
garbage collection. If the parameter is zero the allocation
will follow the default procedure. For systems with fixed
core size, positive and zero parameter will probably be
equivalent.
Result: Forces a garbage collection for non-negative parameter.
Returns the integer value in bits of the amount of more
memory that this program can allocate without causing an
error interrupt. For a virtual memory machine, the returned
value is virtual core. If the parameter is negative, then
the returned value is as said above minus present amount of
garbage.
DECsystem-10 SIMULA Language Handbook, part III Page 52
4.6.2 VIRTUAL MEMORY HANDLING (OR OVERLAY FACILITY)
4.6.2 VIRTUAL MEMORY HANDLING
This might use the overlay mechanism built into the
DECsystem-10 linking loader. Overlay might be between
separately compiled segments in SIMULA. Problems may occur
with unique-numbered entry-points and with the debugging
system?
If overlay is considered, overlaying of SIMDDT with some
other system functions should also be considered at the same
time.
Implementing overlay into the DECsystem-10 SIMULA system
will give many technical difficulties with the debugging
system, prototypes etc. and should perhaps therefore have
low priority, especially if the virtual memory system could
be used instead.
A way of making the virtual memory system on the
DECsystem-10 work as an overlay system, with high
efficiency, is to make a small change to the page fault
handler allowing a user program to ask for certain pages to
be swapped out. We could then add to the SIMULA system a
**** PROCEDURE swap, with one or more parameters which are either
EXTERNAL PROCEDUREs, or REF-s qualified by EXTERNAL CLASSes.
SWAP will swap out all pages containing only object code for
the parameter PROCEDUREs and CLASSes. Note that the
REF-parameters to SWAP may have the value NONE and still
cause swapping out of object code. Prefixing classes are
not swapped out if not explicitly indicated.
Example of use:
BEGIN
EXTERNAL PROCEDURE p; EXTERNAL CLASS a, b, c;
EXTERNAL PROCEDURE swap;
COMMENT a is prefix to b, b is prefix to c;
REF (a) pa; REF(b) pb; REF(c) pc;
swap(p,pb,pc); COMMENT will swap out the object
code of p, b and c, but not the object code of a;
END;
At the same time, we should perhaps add procedures to SIMULA
to be able to set the physical core limit and the physical
guideline from a SIMULA program.
**** BOOLEAN PROCEDURE corelimit(i); INTEGER i;
COMMENT sets PHYSICAL CORE LIMIT. The parameter "i" is
limit in bits. To get limit in pages, multiply by 36*512
(if wordsize is 36 bits and pagesize is 512 words). E.G.
CORELIMIT(50*36*512) will set a limit of 50 pages. Returns
TRUE if setting was successful;
DECsystem-10 SIMULA Language Handbook, part III Page 53
4.6.2 VIRTUAL MEMORY HANDLING (OR OVERLAY FACILITY)
? Perhaps the parameter should be given in number of pages,
not in number of bits????
**** BOOLEAN PROCEDURE COREGUIDE(i); INTEGER i;
COMMENT same for setting physical guideline;
4.7 ENVIRONMENT ENQUIRY
**** INTEGER PROCEDURE maxint
The largest positive integer number.
**** LONG REAL PROCEDURE maxreal
The largest positive long real number.
**** LONG REAL PROCEDURE minreal
The smallest normalized positive real number.
**** INTEGER PROCEDURE approx(a,b); [LONG] REAL a,b;
COMMENT Returns number of bits differing, or, if overflow, -
maxint;
**** INTEGER PROCEDURE DIMENSIONS
Parameters: One of kind ARRAY.
Result: Number of dimensions (subscripts) of the ARRAY.
**** TEXT PROCEDURE IMPLEMENTATION
Parameters: none
Result: Returning a text reference to a text object with the
value "DEC-10 KI" ("IBM 370/145", "UNIVAC 1110", etc). The
exact wording of this text is decided by each
implementation, but the first word should indicate
manufacturer, the following type and model if possible. The
procedure may optionally return the version of the SIMULA
system e.g. "IBM 370/145 VERSION 3.03".
A list of what the returned reference should begin with for
some wellknown computers: "IBM 360", "IBM 370", "UNIVAC
11", "DEC-10", "CDC CYBER", "CII", "ICL SYSTEM-4", etc.
DECsystem-10 SIMULA Language Handbook, part III Page 54
4.7 ENVIRONMENT ENQUIRY
**** TEXT PROCEDURE LOGINFO
Parameters: none
Result: Returns a text reference, machine-dependent, with the
information customarily given at LOGIN or in a JOB card.
(Monitor version, Project number, programmer number,
external job number, internal job number, priorities,
protection privilegies etc.)
4.8 PACKING INTO PARTS OF WORDS
By Stephan Oldgren, ENEA Data AB
This chapter describes two general-purpose and
machine-independent packing procedures. They will make it
easier to produce programs which can be moved to other
computers than the DECsystem-10. Chapter 7 below describes
more efficient, less general-purpose and more
machine-dependent packing procedures.
**** BOOLEAN PROCEDURE PACK and
**** BOOLEAN PROCEDURE UNPACK are two external MACRO-10
procedures which pack and unpack data in parts of words.
4.8.1 PACK and UNPACK, PARAMETERS
In the most simple case the procedures can be called with
four parameters as follows:
Parameter kinds for procedure PACK:
Parameter 1: The area into which data are to be packed.
This parameter can be of type INTEGER, REAL, LONG
REAL or BOOLEAN and of kind SIMPLE or ARRAY.
The procedure will check that the bounds of this
area are not exceeded.
Parameter 2: A non-negative INTEGER which specifies the
number of bits to be bypassed at the beginning of
the area specified in parameter 1, before start of
packing. The purpose of this is to allow partial
packing and unpacking.
Parameter 3: The data to be packed. This parameter can be
DECsystem-10 SIMULA Language Handbook, part III Page 55
4.8 PACKING INTO PARTS OF WORDS
of type INTEGER, REAL, LONG REAL, CHARACTER,
BOOLEAN or TEXT and of kind SIMPLE or ARRAY.
Observe that TEXT variables should not be NOTEXT.
Parameter 4: An INTEGER indicating the size in number of
bits of the packed field. If parameter 3 is an
array parameter 4 is the size for one element of
the array . The value of this parameter must be
as follows:
Type of less than greater than
parameter 3 or equal or equal
INTEGER WORD LENGTH 2
REAL - " - 10
CHARACTER - " - 7
BOOLEAN - " - 1
LONG REAL DOUBLE WORD LENGTH 10
TEXT 7 6
The procedure will also accept any even number of parameters
up to thirty. Then parameters 5,7 etc. are of the same
kind as parameter 3 and parameters 6,8 etc. are of the same
kind as parameter 4.
The procedure UNPACK takes the same parameters as procedure
PACK and works conversely.
All packing and unpacking is done independently of word
boundaries. If for example parameter 2 is 70 and parameter
4 is 6, then the data will be packed into a 6-bit area
consisting of the last two bits in the second word of
parameter 3, and the first four bits of the third word.
4.8.2 PACK and UNPACK, ERROR HANDLING
The program will be interrupted if the number of parameters
is less than four or not even. Before the interrupt, the
following messages is written:
"PARAMETER IS MISSING IN <procedure name> PROCEDURE"
"? ERROR IN JOB ...."
"ZYQ214 ERROR IN UTILITY PROCEDURE"
Control is transferred to SIMDDT.
DECsystem-10 SIMULA Language Handbook, part III Page 56
4.8.1 PACK and UNPACK, PARAMETERS
In the following cases the BOOLEAN procedure PACK will
return the value FALSE:
a) Parameters are of illegal type or kind.
b) Bounds of area specified in Parameter 1 are exceeded.
c) TEXT variable is NOTEXT.
d) Parameter 4(,6 etc) has illegal value.
e) Truncated bits of an INTEGER variable are significant
(ie. contain ones if positive variable or zeroes if
negative variable).
The procedure UNPACK will return FALSE in the same cases.
4.8.3 PACK and UNPACK, METHODS OF PACKING
INTEGERs and BOOLEANs are packed by deleting bits after the
sign bit at the start of the word to be packed.
CHARACTERs are packed by deleting the necessary bits in the
left part of the word to be packed.
REALs and LONG REALs are packed by deleting as many bits as
necessary at the low order end of the (single or double)
word to be packed.
TEXTs are packed by conversion of the characters from
ASCII-7 to SIXBIT if the parameter for size of the packed
field is 6. If the parameter is 7 , each character is
transferred without conversion. LENGTH and POS are not
packed implicity.
4.8.4 PACK and UNPACK, METHODS OF UNPACKING
INTEGERs and BOOLEANs are unpacked by copying the sign bit
into the previously deleted bits.
CHARACTERs are unpacked by returning previously deleted bits
as zeroes.
REALs and LONG REALs are unpacked by filling up the
previously deleted bits with zeroes.
TEXTs are unpacked by conversion of the characters from
SIXBIT to ASCII-7 if the parameter for size of the packed
field is 6. If the parameter is 7, each character is
transferred without conversion. The LENGTH of the TEXT
indicates the number of characters to unpack.
DECsystem-10 SIMULA Language Handbook, part III Page 57
4.8.5 PACK and UNPACK, EXAMPLES
4.8.5 PACK and UNPACK, EXAMPLES
Example of SIMULA main program:
BEGIN
EXTERNAL BOOLEAN PROCEDURE pack,unpack;
BEGIN
ARRAY pool[1:100];
INTEGER i,j;
TEXT t,s;
! check integer;
i:=-5;
Outint(i,2); Outimage;
pack(pool,0,i,5);
unpack(pool,0,j,5);
Outint(j,2); Outimage;
! check text;
t:- Copy("*?AZz");
s:- Blanks(5);
Outtext(t); Outimage;
pack(pool,30,t,6);
unpack(pool,30,s,6);
Outtext(s); Outimage;
! check illegal;
pack(pool,0,t);
END;
END of program
Example of output from execution of the program above:
-5
-5
*?AZz
*?AZZ
PARAMETER IS MISSING IN PACK PROCEDURE
? ERROR IN JOB 15 AT PACK O 002314
ZYQ214 ERROR IN UTILITY PROCEDURE
*
DECsystem-10 SIMULA Language Handbook, part III Page 58
4.9 MIN AND MAX
4.9 MIN AND MAX
These procedures are efficient - almost no overhead.
**** INTEGER PROCEDURE imax(x,y);
INTEGER x,y;
rmax:=IF x>y THEN x ELSE y;
**** INTEGER PROCEDURE imin(x,y);
INTEGER x,y;
imin:=IF x<y THEN x ELSE y;
**** REAL PROCEDURE rmax(x,y);
REAL x,y;
rmax:=IF x>y THEN x ELSE y;
**** REAL PROCEDURE rmin(x,y);
REAL x,y;
rmin:=IF x<y THEN x ELSE y;
**** LONG REAL PROCEDURE lmax(x,y);
LONG REAL x,y;
lmax:=IF x>y THEN x ELSE y;
**** LONG REAL PROCEDURE lmin(x,y);
LONG REAL x,y;
lmin:=IF x<y THEN x ELSE y;
DECsystem-10 SIMULA Language Handbook, part III Page 59
5. ROUTINES WRITEABLE IN SIMULA.
5. ROUTINES WRITEABLE IN SIMULA
----------------------------
NOTE: Some of these routines are not yet written. See the
list in chapter 0.2, which indicates which routines are
ready and which are not.
Most of the routines are writeable or almost writeable in
SIMULA, and the SIMULA code for the procedures is given in
full below to make it easy to move programs to installations
which do not provide these procedures in their libraries.
For certain procedures below, some TEXT parameters are
VALUE-specified. In these cases, an assembly procedure can
usually be written which gives the same result in all cases
without actually making any VALUE copying of the TEXT.
However, a corresponding procedure written entirely in
SIMULA must be VALUE- or NAME-specified to allow TEXT
constants as actual parameters.
5.1 PARTITIONING OF TEXTS
**** TEXT PROCEDURE rest(t); TEXT t;
Returns a subtext reference of a text starting at Pos.
IF t =/= NOTEXT THEN
rest:- t.Sub(t.pos,t.Length-t.pos+1);
**** TEXT PROCEDURE front(t); TEXT t;
Returns a reference to the longest subtext of T before Pos.
IF t =/= NOTEXT THEN
front:- t.Sub(1,t.pos-1);
**** TEXT PROCEDURE from(t,i); TEXT t; INTEGER i;
Returns a reference to the longest subtext of T starting at
Pos = I.
IF i <= t.Length THEN
from:- IF i <= 0 THEN t ELSE t.Sub(i,t.Length-i+1);
**** TEXT PROCEDURE upto(t,i); TEXT t; INTEGER i;
Returns a reference to the longest subtext of T before Pos =
I.
IF i > 0 THEN
upto:- IF i > t.Length THEN t ELSE t.Sub(1,i-1);
DECsystem-10 SIMULA Language Handbook, part III Page 60
5.1 PARTITIONING OF TEXTS
**** TEXT PROCEDURE frontstrip(t); TEXT t;
Returns a reference to the longest subtext of T starting
with the first non-blank character.
BEGIN
t.Setpos(1);
WHILE t.More DO
IF t.Getchar NE ' ' THEN
BEGIN
frontstrip:- t.Sub(t.pos-1,t.Length-t.pos+2);
t.Setpos(0);
END;
END;
**** CHARACTER PROCEDURE fetchar(t,p); TEXT t; INTEGER p;
Returns the P:th character from T.
IF p >= 1 AND p <= t.length THEN
fetchar:= t.Sub(p,1).Getchar;
**** PROCEDURE depchar(t,p,c); TEXT t; INTEGER p; CHARACTER c;
Deposits the character C in the text T at position P. If P
is out of range, no action will be taken;
IF p >= 1 AND p <= t.Length THEN
t.Sub(p,1).Putchar(c);
**** TEXT PROCEDURE tsub(t,p,l); TEXT t; INTEGER p,l;
TSUB acts like text attribute Sub. In cases where
t.Sub(p,l) would have caused a run time error, NOTEXT is
returned.
IF p >= 1 AND l >= 0 AND p+l <= t.Length + 1 THEN
tsub:- t.Sub(p,l);
**** TEXT PROCEDURE getitem(tt); NAME tt; TEXT tt;
First any blanks or tabs after POS in the text are skipped.
Then the procedure reads an item. By an item is meant
either an identifier (a letter followed by letters, digits)
or a number (a series of digits which may contain one dot)
or any other character except blank.
The input text "IF CAR.WHEEL_SIZE > 13.5" will thus by
successive calls to GETITEM give:
IF/CAR/./WHEEL/_/SIZE/>/13.5
The result is a reference to a subtext (not a copy) of the
DECsystem-10 SIMULA Language Handbook, part III Page 61
5.1 PARTITIONING OF TEXTS
text passed as a parameter, or NOTEXT if there are only
blanks left or pos > length.
Notes:
1. The position of the parameter starts from current pos.
2. Preceding blanks or tabs (if any) are skipped.
3. The resulting position indicator setting is that
following the last character of the matched word;
IF tt =/= NOTEXT THEN
BEGIN
CHARACTER window; INTEGER startpos; TEXT t;
CHARACTER PROCEDURE Getchar;
IF t.more THEN
Getchar:= window:= t.Getchar ELSE GOTO out;
BOOLEAN PROCEDURE idchar(c); CHARACTER c;
idchar:= letter(c) OR digit(c);
t:- tt; t.Setpos(tt.Pos);
startpos:= t.length+1;
Getchar;
WHILE window = ' ' OR window = Char(9) DO Getchar;
startpos:= t.Pos-1;
IF NOT letter(window) THEN
BEGIN
IF digit(window) THEN WHILE digit(Getchar) DO;
IF window = '.' THEN WHILE digit(Getchar) DO;
END ELSE WHILE idchar(Getchar) DO;
IF t.Pos > startpos + 1 THEN t.Setpos(t.Pos-1);
out:
getitem:- t.Sub(startpos,t.Pos-startpos);
tt.Setpos(t.Pos);
END;
NOTE
The procedures INITEM, LOOKAHEAD, OUTLINE,
BREAKOUTLINE, INLINE all have a file reference
parameter. It may not be omitted - but may be NONE,
in which case SYSIN or SYSOUT are assumed as
appropriate.
**** TEXT PROCEDURE initem(fileref);
REF(infile COMMENT or directfile;) fileref;
Same as GETITEM for files. LASTITEM is called before
reading an item. NOTEXT is returned if only blanks or tabs
are left in the file or if ENDFILE is TRUE. Note that since
the ITEM-s are not copied, a call on INITEM may cause
inimage and thus destroy previously located items, if they
DECsystem-10 SIMULA Language Handbook, part III Page 62
5.1 PARTITIONING OF TEXTS
have not been copied by the program.
INSPECT fileref DO
initem:- IF lastitem THEN NOTEXT
ELSE getitem(image);
5.2 SEARCHING AND TESTING OF TEXTS
**** TEXT PROCEDURE scanto(tt,c); NAME tt; VALUE c;
TEXT tt; CHARACTER c;
SCANTO will scan from pos in TT until the next occurrence of
the character C. Pos of TT will be placed after the
character found, and the subtext from previous pos up to but
not including the found character will be returned as result
(not copied). If no C is found, the rest of the text is
returned.
BEGIN TEXT t; INTEGER p;
t:- tt; p:= t.pos;
WHILE t.more DO
IF t.getchar = c THEN
BEGIN
scanto:- t.sub(p,t.pos-p-1);
GOTO out;
END;
scanto:- from(t,p);
out: tt.setpos(t.pos);
END of scanto;
**** CHARACTER PROCEDURE findtrigger(master,triggers);
NAME master; TEXT master,triggers;
Starting from current MASTER.POS, find first occurrence of
any of the characters in TRIGGERS.
BEGIN CHARACTER c; TEXT t;
t:- master;
WHILE t.More DO
BEGIN c:= t.Getchar;
triggers.Setpos(1);
IF scanto(triggers,c) =/= triggers THEN
BEGIN !C found in triggers;
findtrigger:= c;
GO TO out;
END
END loop;
out: master.Setpos(t.Pos);
END of findtrigger;
DECsystem-10 SIMULA Language Handbook, part III Page 63
5.2 SEARCHING AND TESTING OF TEXTS
**** TEXT PROCEDURE skip(tt,c); NAME tt; TEXT tt; CHARACTER c;
Skip will skip all characters C in the text T starting from
T.POS. IF the next character (at T.POS) is not equal to C,
T.POS will remain unaltered, otherwise it will be situated
at the first character not equal to C. Skip will also
return the subtext rest of t. ;
BEGIN TEXT t;
t:- tt;
WHILE t.More DO
IF t.Getchar NE c THEN
BEGIN t.Setpos(t.Pos-1);
skip:- t.Sub(t.Pos,t.Length-t.Pos+1);
GO TO out
END;
out: tt.Setpos(t.Pos)
END of skip;
**** BOOLEAN PROCEDURE frontcompare(string, config);
VALUE config; TEXT string, config;
Starting at current pos, does STRING begin with a substring
equal to CONFIG?
IF string.Length - string.pos + 1 >= config.Length THEN
frontcompare:=
string.Sub(string.pos,config.Length) = config;
**** BOOLEAN PROCEDURE upcompare
Upcompare is similar to frontcompare except that a match is
found also when the character in the first parameter string
is a lower case letter and the other character is upper case
of the same letter.
**** INTEGER PROCEDURE search(master, config);
TEXT master, config;
Returns pos of 1st character of the first substring equal to
config, starting at the current Pos of MASTER. If no such
subtext exists, then the result is MASTER.Length+1.
BEGIN
WHILE master.Length - master.Pos + 1 >= config.Length DO
IF master.Sub(master.Pos,config.Length) = config THEN
GO TO out ELSE
master.Setpos(master.Pos+1);
master.Setpos(0);
out:
search:= master.Pos;
END of search;
DECsystem-10 SIMULA Language Handbook, part III Page 64
5.2 SEARCHING AND TESTING OF TEXTS
**** INTEGER PROCEDURE checkint(t); NAME t; TEXT t;
CHECKINT analyses the text t from t.pos and on.
If a getint operation from this position is legal the
returned value is +1. If it would give an error - then
if the remaining text string is blank, the result is 0,
otherwise -1. Pos is placed after a legal item (+1),
after the first non-blank illegal character (-1) or after
the text if the rest is empty (0).
C.f. SCANINT.
Maxintegerlength and Maxfloatinteger are implementation
dependent.
See also procedure GETTYPE below.
IF t.Strip.Length < t.Pos THEN t.Setpos(0) ELSE
BEGIN TEXT u; CHARACTER c; INTEGER p; LONG REAL x;
c:= ' '; u:- t;
WHILE (c = ' ' OR c= Char(9)) AND u.More DO c:=
u.Getchar;
IF c = ' ' OR c = Char(9) THEN !checkint:= 0; ELSE
IF c = '+' OR c = '-' THEN
BEGIN c:= ' ';
WHILE c = ' ' AND u.More DO c:= u.Getchar;
IF Digit(c) THEN
BEGIN trymoredigits:
WHILE c = '0' AND u.More DO c:= u.Getchar;
p:= u.Pos - 1;
WHILE Digit(c) AND u.More DO c:= u.Getchar;
p:= (IF NOT Digit(c) THEN u.Pos-1 ELSE u.Pos) - p;
IF p <= maxintegerlength - 1 THEN checkint:= 1
ELSE
IF p > maxintegerlength + 1 THEN checkint:= -1
ELSE
BEGIN
x:= u.Sub(IF NOT Digit(c) THEN u.Pos-p-1 ELSE
u.Pos-p,p).Getreal;
checkint:= IF Abs(x) <= maxfloatinteger THEN 1
ELSE -1
END maxinteger digits;
IF NOT Digit(c) THEN u.Setpos(u.Pos-1);
END digits ELSE
GO TO error
END sign ELSE
IF Digit(c) THEN GO TO trymoredigits ELSE
BEGIN error: checkint:= -1 END;
t.Setpos(u.Pos)
END of checkint;
**** INTEGER PROCEDURE checkreal(t); NAME t; TEXT t;
CHECKREAL analyses the text t from t.pos and on. If a
getreal operation from this position is legal the returned
value is +1. If it would give an error - then if the
remaining text string is blank, the result is 0, otherwise
DECsystem-10 SIMULA Language Handbook, part III Page 65
5.2 SEARCHING AND TESTING OF TEXTS
-1. Pos is placed after a legal item (+1), after the first
non-blank illegal character (-1) or after the text if the
rest is empty (0). C.f. SCANREAL.
Ln10, Lowtencharacter, Lnmaxreal, Maxdigits are
implementation dependent. See also procedure GETTYPE below.
IF t.Strip.Length < t.Pos THEN t.Setpos(0) ELSE
BEGIN TEXT u; CHARACTER c; INTEGER expitem,p,p2;
LONG REAL decitem;
PROCEDURE skip;
BEGIN c:= ' ';
WHILE (c = Char(9) OR c = ' ') AND u.More DO c:=
u.Getchar
END of skip;
decitem:= 1.0&&0;
u:- t; skip; p:= u.Pos - 1;
IF c = ' ' OR c = Char(9) THEN !checkreal:= 0; ELSE
IF c = lowtencharacter THEN
BEGIN testexp: skip; p:= u.Pos - 1;
IF c = '+' OR c = '-' THEN
BEGIN c:= ' ';
WHILE c = ' ' AND u.More DO c:= u.Getchar END;
IF Digit(c) THEN
BEGIN WHILE Digit(c) AND u.More DO c:= u.Getchar;
p2:= IF NOT Digit(c) THEN u.Pos - 1 ELSE u.Pos;
u.Setpos(p);
IF checkint(u) = 1 THEN expitem:= u.Sub(p,
p2-p).Getint ELSE
GO TO error;
u.Setpos(p2+1);
IF decitem = 0 THEN checkreal:= 1 ELSE
IF Ln(Abs(decitem)) + expitem*ln10 < lnmaxreal THEN
checkreal:= 1 ELSE GO TO error
END digit in exponent ELSE GO TO error
END exponent ELSE
IF Digit(c) THEN
BEGIN testdigits: p:= u.Pos - 1;
WHILE Digit(c) AND u.More DO c:= u.Getchar;
p2:= IF NOT Digit(c) THEN u.Pos - 1 ELSE u.Pos;
IF p2 - p > maxdigits - 1 THEN GO TO error;
IF c = lowtencharacter THEN
BEGIN realpart: decitem:= u.Sub(p,p2-p).Getreal;
GO TO testexp END ELSE
IF c = '.' THEN
BEGIN testfrac:
IF u.More THEN c:= u.Getchar;
IF NOT Digit(c) THEN GO TO error;
WHILE Digit(c) AND u.More DO c:= u.Getchar;
p2:= IF NOT Digit(c) THEN u.Pos - 1 ELSE u.Pos;
IF c = lowtencharacter THEN GO TO realpart
END fraction;
IF NOT Digit(c) THEN u.Setpos(u.Pos-1);
checkreal:= 1
END digit ELSE
IF c = '.' THEN GO TO testfrac ELSE
DECsystem-10 SIMULA Language Handbook, part III Page 66
5.2 SEARCHING AND TESTING OF TEXTS
IF c = '+' OR c = '-' THEN
BEGIN c:= ' ';
WHILE c = ' ' AND u.More DO c:= u.Getchar;
GO TO
IF c = lowtencharacter THEN testexp ELSE
IF Digit(c) THEN testdigits ELSE
IF c = '.' THEN testfrac ELSE error;
END sign ELSE
BEGIN error: checkreal:= -1 END;
t.Setpos(u.Pos)
END of checkreal;
**** INTEGER PROCEDURE CHECKFRAC
Same as checkint/checkreal for grouped items.
**** INTEGER PROCEDURE gettype(paratext);
NAME paratext; TEXT paratext;
Investigate the subtext of the parameter without leading
blanks. Will return:
1 If the next item is readable by GETREAL and contains a dot
and/or a lowtencharacter, else
2 If the next item is readable by GETINT, else
3 If the next item begins with a letter, else
4 If the next item is not NOTEXT, else
5 If the next item is NOTEXT(i.e. if the parameter to gettype
is either NOTEXT or a wholly blank TEXT);
This procedure cannot be coded fully machine-independent,
since the maximal size of integers and reals vary with the
machine;
**** INTEGER PROCEDURE hash(t,n); VALUE t; TEXT t; INTEGER n;
Returns a hash coded value of T in the interval [0:N-1]. It
is recommended to choose n as a prime number.
BEGIN
TEXT tstrip; INTEGER a;
tstrip:-frontstrip(t.Strip);
IF tstrip == NOTEXT then hash:= Mod(t.Length,n) ELSE
BEGIN
a:= Rank(tstrip.Getchar);
if tstrip.Length > 3 then
BEGIN
a:= a + 8*Rank(tstrip.Getchar);
a:= a +64*Rank(tstrip.Getchar);
END;
tstrip.Setpos(tstrip.Length);
a:= a + 512*Rank(tstrip.Getchar) + t.Length;
hash:= Mod(a,n);
END;
DECsystem-10 SIMULA Language Handbook, part III Page 67
5.2 SEARCHING AND TESTING OF TEXTS
END of hash;
**** BOOLEAN PROCEDURE menu(t,i,table,n);
NAME i; TEXT t; TEXT ARRAY table; INTEGER i,n;
The MENU procedure is designed to be used for validity
checks in MENU-like command requests. [See chapter 7 - MENY
for command handling in Swedish.]
The MENU procedure will check for nonambiguous
correspondence between T and an element from the text array
TABLE. (Note that an exact match will always be accepted,
even if it is a substring of another table element.) The
table must contain upper case letters only with no trailing
blanks. The input may have lower case letters. If no match
is found, I will return 0. If T is ambiguous, I returns -1,
otherwise the table matching index will be returned. An
example:
! BEGIN TEXT ARRAY menutable[1:5];
! INTEGER index;
! BOOLEAN ok;
! TEXT t;
! menutable[1]:- Copy("STOP");
! menutable[2]:- Copy("START");
! menutable[3]:- Copy("END");
! menutable[4]:- Copy("ENDURE");
! menutable[5]:- Copy("EXIT");
! t:- <... input ...>;
! ok:= menu(t,index,menutable,5);
! OK will become TRUE if T is equal to
START (INDEX = 2)
start (INDEX = 2)
Sta (INDEX = 2)
sto (INDEX = 1)
enD (INDEX = 3)
endure (INDEX = 4)
endu (INDEX = 4)
and FALSE for
ST (INDEX = -1)
x (INDEX = 0)
e (INDEX = -1)
en (INDEX = -1)
EXTERNAL Procedures required: TEXT PROCEDURE upcase;
BEGIN TEXT u; INTEGER j,k,hit;
DECsystem-10 SIMULA Language Handbook, part III Page 68
5.2 SEARCHING AND TESTING OF TEXTS
! Checking the array index bounds: ;
OPTIONS(/A); COMMENT START ARRAY BOUND CHECKING;
u:- table[1];
u:- table[n];;
OPTIONS(/-A); COMMENT NO ARRAY BOUND CHECKING;
u:- upcase(t.Strip);
FOR j:= 1 STEP 1 UNTIL n DO
IF u = table[j] THEN
BEGIN hit:= 1; k:= j; GO TO ready END
ELSE
IF u.Length < table[j].Length THEN
BEGIN
IF u = table[j].Sub(1,u.Length) THEN
BEGIN k:= j; hit:= hit + 1 END
END;
ready:
menu:= hit = 1;
i:= IF hit = 1 THEN k ELSE Sign(-hit)
END of menu;
**** BOOLEAN PROCEDURE lookup(t,ta,low,high,i); NAME i; TEXT t;
TEXT ARRAY ta; INTEGER low,high,i;
Procedure LOOKUP will perform a binary search for T in the
text array TA within the interval [LOW,HIGH]. The text
array contents must be sorted in ASCENDING order! (I.e.
TA[J] < TA[J+1]. Use procedure SORTTA for sorting if
necessary.) If the text is found in TA the matching index I
will be returned (for which TA[I] = T) and LOOKUP will
return TRUE. If the text is NOT found LOOKUP will return
FALSE and I will be either in the range [LOW,HIGH-1] in case
TA[I] > T > TA[I+1] or else I = HIGH if T > TA[HIGH] or I =
LOW-1 IF T < TA[LOW].
Author: Mats Ohlin, FOA 1, S-104 50 STOCKHOLM 80, SWEDEN.
IF low <= high THEN
BEGIN INTEGER j;
OPTIONS(/A); COMMENT START ARRAY BOUND CHECKING;
IF
ta[low] < t AND t < ta[high]
THEN
BEGIN ;
OPTIONS(/-A); COMMENT NO ARRAY BOUND CHECKING;
FOR j:= (low+high)//2 WHILE high > low + 1 DO
IF ta[j] > t THEN high:= j ELSE
IF ta[j] < t THEN low:= j ELSE
BEGIN lookup:= TRUE; GO TO out END
DECsystem-10 SIMULA Language Handbook, part III Page 69
5.2 SEARCHING AND TESTING OF TEXTS
END inside range ELSE
IF ta[low] = t THEN
BEGIN lookup:= TRUE; j:= low END ELSE
IF ta[high] = t THEN
BEGIN lookup:= TRUE; j:= high END ELSE
IF ta[low] > t THEN j:= low - 1 ELSE
IF ta[high] < t THEN j:= high;
out: i:= j
END of lookup;
5.3 OPERATIONS ON TEXTS
**** LONG REAL PROCEDURE scanreal(t); NAME t; TEXT t;
Scanreal is similar to GETREAL, but the handling of ERROR
conditions due to bad data is different. Scanreal returns
the value of the next real item in the text T. T.Pos will
only be moved if deediting was successful.
BEGIN TEXT s; INTEGER p;
p:= t.Pos; s:- rest(t);
scanreal:= s.Getreal;
! *** If this goes wrong, return -MAXREAL ELSE
t.Setpos(p+s.Pos-1);
END of scanreal;
**** INTEGER PROCEDURE scanint(t); NAME t; TEXT t;
Scanint is similar to GETINT, but the handling of error
conditions due to bad data is different. Scanint returns
the value of the next integer item in the text T. T.Pos
will only be moved if deediting was successful.
BEGIN TEXT s; INTEGER p;
p:= t.Pos; s:- rest(t);
scanint:= s.Getint;
! *** If this goes wrong, return -MAXINT-1 ELSE
t.Setpos(p+s.Pos-1)
END of scanint;
DECsystem-10 SIMULA Language Handbook, part III Page 70
5.3 OPERATIONS ON TEXTS
**** INTEGER PROCEDURE scanfrac
Same as scanint/scanreal for grouped items.
**** TEXT PROCEDURE conc(t,...); TEXT t,...;
Text concatenation procedure. Variable number of TEXT
parameters. Since the number of parameters is variable,
CONC can NOT be written in SIMULA. The parameters are
handled as if transferred in reference mode, although
constants are allowed.
**** TEXT PROCEDURE conc2(t1,t2); VALUE t1, t2; TEXT t1, t2;
T1 and T2 are handled as if transferred by reference (text
descriptors are copied) although constants are allowed.
BEGIN TEXT c;
c:- blanks(t1.Length+t2.Length);
c.Sub(1,t1.Length):= t1;
c.Sub(1+t1.Length,t2.Length):= t2;
conc2:- c;
END;
**** BOOLEAN PROCEDURE puttext(oldstring, newstring);
NAME oldstring; VALUE newstring;
TEXT oldstring, newstring;
Puts the short word newstring into the long string
oldstring. Newstring is OUTPUT after POS in oldstring, and
POS of oldstring is moved after the end of the new word.
Returns FALSE if there was not room for the new string.
BEGIN TEXT s;
s:- oldstring;
IF s.Pos+newstring.length-1 <=
s.length THEN
BEGIN
puttext:= true;
s.Sub(s.Pos,newstring.length):=
newstring;
s.Setpos(s.Pos+newstring.length);
END;
oldstring.Setpos(s.Pos);
END;
DECsystem-10 SIMULA Language Handbook, part III Page 71
5.3 OPERATIONS ON TEXTS
**** TEXT PROCEDURE upcase(t); TEXT t;
Will convert all lower case letters within T to the
corresponding upper case letter. No copying of the text.
Only English alphabet letters (for which the procedure
"letter" returns TRUE) are converted.
IF t =/= NOTEXT THEN
BEGIN
CHARACTER c; INTEGER shift;
shift:= rank('a') - rank('A');
t.Setpos(1);
WHILE t.more DO
BEGIN
c:= t.Getchar;
IF letter(c) AND c >= 'a' AND c <= 'z' THEN
BEGIN
c:= char(rank(c) - shift);
t.Setpos(t.Pos-1); t.Putchar(c);
END;
END;
t.Setpos(1);
upcase:- t;
END;
**** TEXT PROCEDURE lowcase(t); TEXT t;
LOWCASE is the opposite of UPCASE. Defined via simple
modifications of the UPCASE procedure definition. Just
exchange 'a' with 'A' and 'z' with 'Z'.
**** TEXT PROCEDURE maketext(c,n); CHARACTER c; INTEGER n;
Returns a new text of length N filled with character C.
IF n > 0 THEN BEGIN
TEXT t;
t:- blanks(n);
WHILE t.More DO t.putchar(c);
t.Setpos(1); maketext:- t;
END;
**** TEXT PROCEDURE compress(t,c); TEXT t; CHARACTER c;
COMPRESS returns NOTEXT (if T contains no other characters
than a number of characters = C), or a reference to an
initial subtext of T (altered) which contains all characters
of T not = C. The part of T after this subtext is
unchanged.
Example: t1:-Copy("AxBxCxDx"); t2:-compress(t1,'x');
gives t1="ABCDCxDx", t2==t1.Sub(1,4), t2="ABCD".
BEGIN TEXT s; CHARACTER cc;
DECsystem-10 SIMULA Language Handbook, part III Page 72
5.3 OPERATIONS ON TEXTS
t.Setpos(1); s:- t;
WHILE t.More DO
BEGIN cc:= t.Getchar;
IF cc NE c THEN s.Putchar(cc);
END;
compress:- front(s)
END of compress;
**** INTEGER PROCEDURE startpos(t); TEXT t;
Procedure STARTPOS returns the starting position of the
(sub)text T within T.Main. Thus if T is a main text (T ==
T.Main) the result is 1. If T == NOTEXT, 0 is returned.
Efficient MACRO-10 coded routine.
IF t =/= NOTEXT THEN
BEGIN TEXT s; INTEGER p;
s:- t.Main;
IF s == t THEN startpos:= 1 ELSE
BEGIN
WHILE s.More DO
BEGIN
p:= search(s,t);
IF s.Sub(p,t.Length) == t THEN
BEGIN startpos:= p; GO TO out END;
s.Setpos(p+1);
END loop
END not main text;
out:
END of startpos;
**** PROCEDURE split(t,t1,delimiter,t2);
NAME t1,t2; TEXT t,t1,delimiter,t2;
EXTERNAL Procedures required:
TEXT PROCEDURE front,rest.
INTEGER PROCEDURE search;
This procedure splits the text T into two halves - the first
part T1 denoting the part of T up to the text DELIMITER -
and the second part T2 denoting the part of T following the
DELIMITER. Thus T1 + DELIMITER + T2 = T. However, if no
DELIMITER is found, T1 will return a reference to the whole
of T, while T2 will return NOTEXT. Note - if the delimiter
is just one character long, procedure SCANTO is recommended
for efficiency reasons.
BEGIN TEXT s1;
t.Setpos(1);
t.setpos(search(t,delimiter));
s1:- front(t);
t.Setpos(t.pos+delimiter.Length);
t2:- rest(t);
t1:- s1
END of split;
DECsystem-10 SIMULA Language Handbook, part III Page 73
5.3 OPERATIONS ON TEXTS
*** INTEGER PROCEDURE splita(t,del,ta,n);
TEXT t,del; TEXT ARRAY ta; INTEGER n;
This procedure splits the text T into parts separated by the
text delimiter DEL and makes the elements of TA[1:N] denote
the different parts of T (without DEL). The returned value
SPLITA is the number of parts found. However, if more than
N parts are found, the value -1 is returned.
Note that if DEL is just one character, procedure SPLITC is
recommended. SPLITC is roughly twice as efficient as
SPLITA.
Author: Mats Ohlin, FOA 1, Fack, S-104 50 STOCKHOLM 80,
SWEDEN.
EXTERNAL PROCEDURE required: INTEGER PROCEDURE search;
BEGIN INTEGER i,p;
OPTIONS(/A); ta[1]:- ta[n];; ! Check array bounds;
OPTIONS(/-A);
t.Setpos(1);
FOR i:= i+1 WHILE t.More DO
IF i>n THEN
BEGIN splita:= -1; GOTO exit END
ELSE
BEGIN p:= t.Pos;
t.Setpos(search(t,del));
ta[i]:- t.Sub(p,t.Pos-p);
t.Setpos(t.Pos+del.Length);
END;
splita:= i-1;
FOR i:= i STEP 1 UNTIL n DO ta[i]:- NOTEXT;
exit:
END of splita;
**** INTEGER PROCEDURE splitc(t,del,ta,n);
TEXT t; CHARACTER del; TEXT ARRAY ta; INTEGER n;
This procedure splits the text T into parts separated
by the character delimiter DEL and makes the elements of
TA[1:N] denote the different parts of T (without DEL).
The returned value SPLITC is the number of parts found.
However, if more than N parts are found, the value -1 is
returned.
Author: Mats Ohlin, FOA 1, Fack, S-104 50 STOCKHOLM 80,
SWEDEN.
EXTERNAL PROCEDURE required: TEXT PROCEDURE scanto;
BEGIN INTEGER i;
OPTIONS(/A); ta[1]:- ta[n];; ! Check array bounds;
OPTIONS(/-A);
t.Setpos(1);
FOR i:= i+1 WHILE t.More DO
DECsystem-10 SIMULA Language Handbook, part III Page 74
5.3 OPERATIONS ON TEXTS
IF i>n THEN
BEGIN splitc:= -1; GOTO exit END
ELSE ta[i]:- scanto(t,del);
splitc:= i-1;
FOR i:= i STEP 1 UNTIL n DO ta[i]:- NOTEXT;
exit:
END of splitc;
**** BOOLEAN PROCEDURE change(master,oldt,newt); NAME master;
TEXT master,oldt,newt;
EXTERNAL Procedures required: TEXT PROCEDURE
conc,from,front.
INTEGER PROCEDURE search.
Change will change the subtext OLDT in MASTER - if found
when searching from MASTER.POS and on - to NEWT. If
OLDT.Length >= NEWT.Length then MASTER will denote (a
subtext of) the original MASTER text, otherwise MASTER will
denote a new text object. Changing all occurrences of OLDT
to NEWT may be done with the following procedure;
! PROCEDURE edit(master,oldt,newt);
! NAME master;
! TEXT master,oldt,newt;
! BEGIN TEXT local;
! local:- master;
! WHILE local.More DO change(local,oldt,newt);
! master:- local
! END of edit;
BEGIN TEXT local; INTEGER p;
local:- master;
p:= search(local,oldt);
IF p <= local.Length THEN
BEGIN change:= TRUE;
IF oldt.Length >= newt.Length THEN
BEGIN local.Sub(p,newt.Length):= newt;
IF oldt.Length > newt.Length THEN
BEGIN
from(local,p+newt.Length):=
from(local,p+oldt.Length);
local:- local.Sub(1,
local.Length-oldt.Length+newt.Length)
END
END ELSE
local:-
conc(front(local),newt,from(local,p+oldt.Length));
local.Setpos(p+newt.Length);
master:- local
END ELSE master.Setpos(0);
END of change;
DECsystem-10 SIMULA Language Handbook, part III Page 75
5.3 OPERATIONS ON TEXTS
**** TEXT PROCEDURE puttime(field,time,unit,secdec);
TEXT field; REAL time;
CHARACTER unit; INTEGER secdec;
Puttime edits a REAL variable representing a TIME value
left justified into the text FIELD in
seconds if UNIT = 'S'
minutes if UNIT = 'M'
hours if UNIT = 'H'
days if UNIT = 'D'
Else Putreal editing will be used.
The FIELD must have a minimum length of
12 if secdec < 0
15 if secdec = 0
16+secdec if secdec > 0
Format:
[-]dddD hh:mm[.ss[.xxx...]]
where
ddd is number of days (Blanked if day < 1)
hh is number of hours
mm is number of minutes
ss is number of seconds (only if SECDEC >= 0)
xxx is fraction of second with SECDEC digits
PUTTIME also returns a reference to parameter FIELD.
Thus it can be used as parameter to Outtext -
i.e. Outtext(puttime(field,Time,'H',-1);
or editing Image directly -
puttime(Image.Sub(Pos,17),Time,'H',-1);
C.f. procedure OUTTIME.
EXTERNAL PROCEDURE required: TEXT PROCEDURE putfloat;
IF field.Length >=
(IF secdec < 0 THEN 12 ELSE IF secdec = 0 THEN 15 ELSE
secdec+16)
THEN
BEGIN INTEGER days,hours,m,powersec; REAL seconds;
PROCEDURE fixedit(x,w); REAL x; INTEGER w;
BEGIN
field.Sub(field.Pos,w).Putfix(x,secdec);
field.Setpos(field.Pos+w);
END of fixedit;
PROCEDURE intedit(i,w); INTEGER i,w;
BEGIN
field.Sub(field.Pos,w).Putint(i);
IF field.Getchar = ' ' THEN
BEGIN field.Setpos(field.Pos-1);
field.Putchar('0');
END;
field.Setpos(field.Pos-1+w);
DECsystem-10 SIMULA Language Handbook, part III Page 76
5.3 OPERATIONS ON TEXTS
END of intedit;
BOOLEAN PROCEDURE adjusted;
BEGIN
IF m = 60 THEN
BEGIN adjusted:= TRUE;
hours:= hours + 1; m:= 0;
IF hours = 24 THEN
BEGIN days:= days + 1; hours:= 0 END
END;
field.Sub(2,6):= " D ";
field.Setpos(5);
IF days < 1 THEN
field.Putchar(' ') ELSE
IF days < 10 THEN
BEGIN
field.Setpos(4);
field.Putchar(Char(days+Rank('0')));
END ELSE
IF days < 100 THEN
BEGIN field.Setpos(3); intedit(days,2) END
ELSE
IF days < 1000 THEN
BEGIN field.Setpos(2); intedit(days,3) END
ELSE
IF days <= 9999 AND days >= -999 THEN
BEGIN field.Setpos(1); intedit(days,4) END
ELSE
field.Sub(1,4):= "****";
field.Setpos(8);
intedit(hours,2); field.Putchar(':');
END of adjust;
powersec:= 1;
FOR m:= 1 step 1 UNTIL secdec DO powersec:= powersec*10;
IF unit = 'D' THEN time:= 1440*time ELSE
IF unit = 'H' THEN time:= 60*time ELSE
IF unit = 'M' THEN ELSE
IF unit = 'S' THEN time:= time/60 ELSE
BEGIN putfloat(field,time);
GO TO stop
END;
field.Setpos(1);
field.Putchar(IF time < 0 THEN '-' ELSE ' ');
time:= Abs(time);
IF time > 34 359 738 367 THEN GO TO error;
m:= Entier(time);
seconds:= 60*(time - m);
hours:= m//60;
m:= Mod(m,60);
days:= hours//24;
hours:= Mod(hours,24);
IF secdec >= 0 THEN
BEGIN
IF Entier(seconds*powersec+0.5) = 60*powersec THEN
DECsystem-10 SIMULA Language Handbook, part III Page 77
5.3 OPERATIONS ON TEXTS
BEGIN m:= m + 1; seconds:= 0 END;
adjusted;
intedit(m,2); field.Putchar('.');
IF seconds < 9.5 THEN
BEGIN field.Putchar('0');
fixedit(seconds,
IF secdec = 0 THEN 1 ELSE secdec+2)
END ELSE
fixedit(seconds,IF secdec = 0 THEN 2 ELSE secdec+3);
END ELSE
BEGIN time:= m + seconds/60;
m:= time;
IF adjusted THEN time:= 0;
IF time < 9.5 THEN field.Putchar('0');
secdec:= 0;
fixedit(time,IF time < 9.5 THEN 1 ELSE 2)
END;
stop:
field.Setpos(1); puttime:- field
END of puttime OK ELSE
error:
BEGIN field.Setpos(1);
puttime:- putfloat(field,time);
END of puttime error;
**** TEXT PROCEDURE putfloat(t,x); TEXT t; REAL x;
PROCEDURE PUTFLOAT edits a number X into the text T (right
justified).
Insignificant trailing zeros in fractions are removed.
Representation errors (of type 98.9999999) are corrected.
If fixed point format cannot be used (displaying significant
digits), floating point format is used instead. The output
will depend on the length of the text T. A value in the
range [8,16] is recommended.
PUTFLOAT also returns a reference to the text parameter.
TEXT PROCEDURE putfloat(t,x); TEXT t; REAL x;
BEGIN INTEGER w;
w:= t.Length; t:= NOTEXT;
IF w = 0 THEN ! NOTEXT !; ELSE
IF x = 0 THEN t.Sub(w,1).Putchar('0') ELSE
BEGIN REAL saved; BOOLEAN negative;
INTEGER d,i,pow,j;
negative:= x < 0; d:= 8; ! No. of sign. digits;
saved:= x; x:= Abs(x);
IF x >= &8 OR x < &-7 THEN
realedit:
DECsystem-10 SIMULA Language Handbook, part III Page 78
5.3 OPERATIONS ON TEXTS
BEGIN pow:= 0;
WHILE x >= 10 DO
BEGIN x:= x*0.1; pow:= pow + 1 END;
WHILE x < 1 DO
BEGIN x:= x*10; pow:= pow - 1 END;
! Calculate length for exp part;
j:= IF pow >= 10 THEN 3 ELSE
IF pow >= 0 THEN 2 ELSE
IF pow >= -9 THEN 3 ELSE 4;
i:= w - j;
IF i > (IF negative THEN 1 ELSE 0) THEN
BEGIN CHARACTER low10; TEXT temp;
putfloat(t.Sub(1,i),x*sign(saved));
t.Setpos(1); IF t.Getchar = '*' THEN GO TO
realcase;
temp:- blanks(4); temp.putreal(1,0);
temp.Setpos(1); low10:= temp.getchar;
t.Setpos(1);
WHILE t.Pos <= i DO
IF t.Getchar = low10 THEN GO TO realcase;
t.Putchar(low10);
t.Sub(i+2,j-1).Putint(pow);
END ELSE
realcase:
BEGIN i:= w - (IF negative THEN 6 ELSE 5);
IF i < 0 THEN i:= 0;
IF d > i THEN d:= i;
t.Putreal(saved,d)
END putreal case
END realedit block ELSE
BEGIN INTEGER pow_d,pow_di,n1,m,di,ix;
pow:= 1;
pow_di:= pow_d:= 100 000 000; ! = 10**d;
! Scale x to [0.1,1-eps] ;
WHILE x >= 1.0 DO
BEGIN x:= x*0.1;
IF pow_di = 1 THEN GO TO realedit;
pow_di:= pow_di//10;
i:= i - 1
END;
WHILE x < 0.1 DO
BEGIN x:= x*10; pow:= pow*10;
i:= i + 1
END;
di:= d + i;
IF di < 0 THEN
BEGIN d:= -i; di:= 0 END;
ix:= x*pow_d; ! IX now integer with full prec;
! Fix 9999.... problem;
j:= Mod(ix,100);
DECsystem-10 SIMULA Language Handbook, part III Page 79
5.3 OPERATIONS ON TEXTS
IF j >= 90 THEN ix:= ix + 100 - j ELSE
IF j <= 10 THEN ix:= ix - j;
n1:= ix//pow_di//pow; ! = Integer Part;
! Calculate j = no. of chars before dec. point;
m:= n1; j:= IF negative THEN 2 ELSE 1;
WHILE m >= 10 DO
BEGIN m:= m//10; j:= j + 1 END loop;
ix:= ix -(n1*pow_di)*pow;
! ix = fraction ;
IF ix NE 0 THEN
! Remove trailing zeros in IX;
WHILE Mod(ix,10) = 0 DO
BEGIN ix:= ix//10; di:= di-1 END mod loop;
IF j + (di+1)*Sign(ix) > w THEN GO TO realedit;
IF negative THEN n1:= -n1;
IF ix = 0 THEN t.Putint(n1) ELSE
BEGIN
j:= w-di;
IF negative AND n1 = 0 THEN
t.Sub(j-2,2):= "-0" ELSE
t.Sub(1,j-1).Putint(n1);
t.Setpos(j); t.Putchar('.');
t.Sub(t.Pos,di).Putint(ix);
! Fill in zeros;
WHILE ix > 0 DO
BEGIN ix:= ix//10; di:= di - 1 END loop;
t.Setpos(j+1);
FOR j:= 1 STEP 1 UNTIL di DO t.Putchar('0');
END fraction present
END w > 0
END x not = 0;
putfloat:- t
END of putfloat;
**** INTEGER PROCEDURE scan(command,n,arg,key,defaultkey);
TEXT command; INTEGER n;
TEXT ARRAY arg,key; INTEGER defaultkey;
Integer procedure SCAN will identify specified KEYs in a
COMMAND text string. SCAN performs - in order -
DECsystem-10 SIMULA Language Handbook, part III Page 80
5.3 OPERATIONS ON TEXTS
1. Does COMPRESS and UPCASE on the COMMAND string
2. If the parm. DEFAULTKEY belongs to [1:N] and COMMAND
string does not start with the text KEY[DEFAULTKEY] then
that key will be assumed present in front of COMMAND.
3. Locates (in order 1 to N) possible occurrences of the
texts defined in text array KEY[1:N].
4. Makes ARG[x] :- whatever follows KEY[x] up to next KEY.
If the KEY is just present, but with no text following
then Blanks(1) is returned. Nonpresent KEY is indicated
with ARG[x] == NOTEXT.
5. SCAN returns index for multiple used key in command
string. Thus, normally SCAN should return zero,
indicating no multiple used key.
Note that the contents of KEY must have Upper case letters
only.
An example:
! BEGIN
! EXTERNAL TEXT PROCEDURE conc,upcase,compress,
! rest,inline,checkextension;
! EXTERNAL CHARACTER PROCEDURE findtrigger;
! EXTERNAL INTEGER PROCEDURE search,scanint,scan;
! EXTERNAL REF (Infile) PROCEDURE findinfile;
! EXTERNAL REF (Outfile) PROCEDURE findoutfile;
!
! TEXT ARRAY key,arg,default[1:6];
! TEXT command,infilename,outfilename;
! INTEGER avalue,index;
! BOOLEAN na,nb;
! REF (Infile) inf;
! REF (Outfile) outf;
!
! key[1]:- Copy("/DEFAULT:/A:/NA/NB/N=");
! ! Save some space with this trick!;
! key[2]:- key[1].Sub(10,3); !/A: ;
! key[3]:- key[1].Sub(13,3); !/NA ;
! key[4]:- key[1].Sub(16,3); !/NB ;
! ! This keyword (5) must come after /NA and /NB
! ! else it will swamp those keys (if present);
! key[5]:- key[1].Sub(19,2); !/N ;
! key[6]:- key[1].Sub(21,1); != ;
! key[1]:- key[1].Sub(1,9); !/DEFAULT: ;
!
! start:
! FOR index:= scan(inline("*",Sysin),6,arg,key,1)
! WHILE index NE 0 DO
! BEGIN Outtext("? Keyword:");
! Outtext(key[index]);
! Outtext(" used more than once.");
! Outtext(" Please try again.");
! Outimage;
DECsystem-10 SIMULA Language Handbook, part III Page 81
5.3 OPERATIONS ON TEXTS
! END loop;
!
! ! Analyze result:;
! ! Assume the user entered: abc=def/A:12/N ;
! ! The result will then be:
! ! arg[1] = "ABC"
! ! arg[2] = "12"
! ! arg[3] == NOTEXT
! ! arg[4] == NOTEXT
! ! arg[5] = " "
! ! arg[6] = "DEF"
! ;
!
! ! Test file information;
! ! Default inputname is outputname;
! IF arg[6] == NOTEXT THEN arg[6]:- arg[1];
! infilename:- arg[6];
!
! ! We also demonstrate a way of checking
! ! entered file specifications;
! IF infilename NE "TTY:" THEN
! BEGIN
! infilename:-
! checkextension(infilename,".EXT");
! FOR inf:- findinfile(infilename) WHILE
! inf == NONE DO
! BEGIN Outtext("? Cannot find Infile:");
! Outtext(infilename);
! Outimage;
! infilename:-
! inline("Enter name of infile:",Sysin);
! infilename:-
! checkextension(infilename,".EXT");
! END loop;
! END not TTY ELSE
! inf:- Sysin;
!
! outfilename:- arg[1];
! IF outfilename NE "TTY:" THEN
! BEGIN
! outfilename:-
! checkextension(outfilename,".EXT");
! FOR outf:-
! findoutfile(outfilename) WHILE outf ==
! NONE DO
! BEGIN
! Outtext("? Cannot create Outfile:");
! Outtext(outfilename);
! Outimage;
! outfilename:-
! inline("Enter name of outfile:",Sysin);
! outfilename:-
! checkextension(outfilename,".EXT");
! END loop
! END ELSE outf:- Sysout;
!
DECsystem-10 SIMULA Language Handbook, part III Page 82
5.3 OPERATIONS ON TEXTS
! ! Check value switch /A: ;
! IF arg[2] == NOTEXT THEN
! BEGIN !.... Set default value arg[2]:- ... ;
! END;
! avalue:= scanint(arg[2]);
! ! Assume range [1,99];
! ! Check result, Pos = 1 is unsuccessful
! deediting, More indicates
! ! superfluous information in value;
! IF avalue < 0 OR avalue > 99 OR arg[2].Pos = 1
! OR arg[2].More THEN
! BEGIN Outtext("? Illegal /A: value:");
! Outtext(arg[2]);
! Outimage;
! GO TO start;
! END;
!
! ! Assume /N short for /NA ;
! IF arg[3] == NOTEXT THEN arg[3]:- arg[5];
! na:= arg[3] =/= NOTEXT;
! ! More strict: IF arg[3] = " " THEN na:= TRUE
! ELSE Error;
! ! Error would indicate the string
! "/NAxxx/....";
!
! nb:= arg[4] =/= NOTEXT;
!
! !....;
!
! END of program
EXTERNAL Procedures required:
TEXT PROCEDURE conc,upcase,compress;
INTEGER PROCEDURE search;
IF n < 1 THEN
BEGIN IF Pos > 1 THEN Outimage;
Outtext("%SCAN - Illegal parm! N < 1.");
Outimage
END ELSE
BEGIN
INTEGER ARRAY keypos[1:n]; INTEGER i,j,posmin,keyposi;
OPTIONS(/A); arg[1]:- arg[n]; key[1]:- key[1];
key[n]:- key[n];; OPTIONS(/-A);
command:- compress(command,' ');
upcase(command);
IF defaultkey > 0 AND defaultkey <= n THEN
BEGIN
IF (IF command.Length < key[defaultkey].Length
THEN TRUE
ELSE command.Sub(1,key[defaultkey].Length)
NE key[defaultkey] ) THEN
command:- conc(key[defaultkey],command);
END default key ELSE command:- Copy(command);
DECsystem-10 SIMULA Language Handbook, part III Page 83
5.3 OPERATIONS ON TEXTS
FOR i:= 1 STEP 1 UNTIL n DO
BEGIN
command.Setpos(1);
j:= search(command,key[i]);
IF j <= command.Length THEN
BEGIN
command.Sub(j,key[i].Length):= NOTEXT;
keypos[i]:= j;
command.Setpos(j+key[i].Length);
IF search(command,key[i]) <= command.Length THEN
BEGIN scan:= i; GO TO exit; END mult key;
END key found
END i loop;
FOR i:= 1 STEP 1 UNTIL n DO
IF keypos[i] > 0 THEN
BEGIN
keyposi:= keypos[i];
! Search smallest keypos[j] > keypos[i];
posmin:= command.Length + 1;
FOR j:= 1 STEP 1 UNTIL n DO
IF keypos[j] > keyposi THEN
BEGIN
IF keypos[j] < posmin THEN posmin:= keypos[j];
END j loop;
j:= keyposi + key[i].Length;
arg[i]:- IF posmin = j THEN Blanks(1) ELSE
command.Sub(j,posmin-j);
END keypos[i] > 0 ELSE arg[i]:- NOTEXT;
exit:
END of scan;
**** SSCAN
is a version of SCAN used by GETVIS (see chapter 1).
SSCAN accepts swedish letters and does not zero the "arg"
array
for unused switches.
**** DECOM
is a package to simplify the writing of SIMULA programs
which accept input in the conventional DEC-10 format:
OUTFIL.EXT/SWITCH1/SWITCH2...=INFIL.EXT/SWITCH3...
DECOM is a subclass of SAFMIN (See SAFEIO).
Files: DECOM.SIM and DECOM.HLP. DECOM.ATR and DECOM.REL are
included in LIBSIM.
Written by Jacob Palme and Mats Ohlin, Swedish National
Defense
Research Institute.
DECsystem-10 SIMULA Language Handbook, part III Page 84
5.3 OPERATIONS ON TEXTS
**** TEXT PROCEDURE radix(base,i); INTEGER base,i;
TEXT PROCEDURE RADIX returns a text containing the
representation of input I in radix BASE. BASE may be
negative but not -1 or zero. Resulting text will never
contain blanks. If BASE = 16 then sequence 0123456789ABCDEF
will be used, otherwise if BASE > 10 then the sequence
0123456789(10)(11)(12)... will be used.
C.f. INTEGER PROCEDURE GETRADIX
Author: Mats Ohlin, FOA 1, Fack, S-104 50 STOCKHOLM,
SWEDEN. Date: 76-12-10
IF i = 0 THEN radix:- Copy("0") ELSE
IF base = 0 OR base = -1 OR base = 1 THEN radix:- Copy("*")
ELSE
BEGIN INTEGER j,ndig,abase; BOOLEAN neg;
TEXT t; REF (dig) xdig;
CLASS dig(c); CHARACTER c;
BEGIN REF (dig) next;
next:- xdig; xdig:- THIS dig;
ndig:= ndig + 1;
END dig;
abase:= base*Sign(base);
IF base > 0 THEN neg:= i < 0;
IF neg THEN i:= -i;
WHILE i NE 0 DO
BEGIN j:= Mod(i,base);
IF j < 0 THEN
BEGIN j:= j - base; i:= i + base END;
! 48 = '0' 55 + 10 = 'A' ;
IF j <= 9 THEN NEW dig(Char(j+48)) ELSE
IF abase = 16 THEN NEW dig(Char(j+55)) ELSE
BEGIN NEW dig(')');
WHILE j NE 0 DO
BEGIN NEW dig(Char(Mod(j,10)+48));
j:= j//10
END;
NEW dig('(');
END unusual base;
i:= i//base;
END loop;
IF neg THEN NEW dig('-');
t:- Blanks(ndig);
WHILE xdig =/= NONE DO
BEGIN t.Putchar(xdig.c); xdig:- xdig.next END;
t.Setpos(1);
radix:- t
END of radix;
DECsystem-10 SIMULA Language Handbook, part III Page 85
5.3 OPERATIONS ON TEXTS
**** INTEGER PROCEDURE getradix(base,t);
INTEGER base; TEXT t;
INTEGER PROCEDURE GETRADIX converts a text T containing
an item in base BASE to the corresponding base-10 integer.
If BASE <= 10 only the characters 012...(BASE-1) may be
used.
If BASE = 16 or -16 then the char:s 0..9 A..F may be used.
For all other bases the sequence should be written:
01...9(10)(11)(12)....
Note that texts containing illegal characters will
always be (somehow) interpreted.
C.f. TEXT PROCEDURE RADIX.
Author: Mats Ohlin, FOA 1, Fack, S-104 50 STOCKHOLM, SWEDEN.
Date: 76-12-10
EXTERNAL Procedures required:
CHARACTER PROCEDURE fetchar;
TEXT PROCEDURE from;
IF t = "0" THEN error: getradix:= 0 ELSE
IF base > 1 OR base < -1 THEN
BEGIN INTEGER sum,b,i,flag; CHARACTER c;
BOOLEAN neg,signflag;
! Skip leading blanks and sign;
FOR c:= fetchar(t,1) WHILE c = ' ' OR c = '+'
OR c = '-' DO
BEGIN t:- from(t,2);
IF c = '-' OR c = '+' THEN
BEGIN neg:= c = '-';
IF signflag THEN GO TO error;
signflag:= TRUE;
END sign;
END c loop;
! Check first char;
IF (IF c = '(' OR Digit(c) THEN TRUE
ELSE 'A' <= c AND c <= 'F' AND (base = 16 OR
base = -16) ) THEN
BEGIN
! See how long the item is;
t.Setpos(1);
WHILE t.More DO
BEGIN c:= t.Getchar;
IF Digit(c) THEN !ok; ELSE
IF c = '(' THEN flag:= flag + 1 ELSE
IF c = ')' THEN flag:= flag - 1 ELSE
IF 'A' <= c AND c <= 'F' AND (base = 16 OR
base = -16) THEN ! OK; ELSE
GO TO endoft;
IF flag < 0 THEN GO TO endoft ELSE
IF flag > 1 THEN
DECsystem-10 SIMULA Language Handbook, part III Page 86
5.3 OPERATIONS ON TEXTS
BEGIN t.Setpos(t.Pos-2);
GO TO endoft END;
END more loop;
endoft: IF t.More THEN t:- t.Sub(1,t.Pos-1);
! Start summation;
b:= 1;
FOR i:= t.Length STEP -1 UNTIL 1 DO
BEGIN
c:= fetchar(t,i);
IF c NE ')' THEN
sum:= sum + b*(Rank(c)-(IF Letter(c) THEN 55
ELSE 48)) ELSE
BEGIN
i:= i - 2;
FOR c:= fetchar(t,i)
WHILE c NE '(' AND i > 1 DO
i:= i - 1;
IF i > 0 THEN
sum:= sum + b*from(t,i+1).Getint;
END (..) ;
IF i > 1 THEN b:= b*base;
END i loop;
getradix:= sum*(IF neg THEN -1 ELSE 1)
END starts with ( or Digit
END of getradix;
**** INTEGER PROCEDURE arrlgd(ta);
TEXT ARRAY ta;
Computes the sum of the lengths of all text array elements
in TA, plus 1 for each element in the array, allowing for a
delimiter after each element. To be used for computing the
length of the second parameter to ARRTXT (see below). Part
of the SIMDBM system.
**** PROCEDURE arrtxt(ta,t,c);
TEXT ARRAY ta; TEXT t; CHARACTER c;
Copies the contents of all elements of TA to T. The
character C is placed after each copied text. Example:
TA[1:4] contains "ABC", "X", "123456", "FINISH". T:-
Blanks(ARRLGD(TA)); ARRTXT(TA,T,',') will make T =
"ABC,X,123456,FINISH,".
Used in the SIMDBM system.
DECsystem-10 SIMULA Language Handbook, part III Page 87
5.4 INPUT/OUTPUT
5.4 INPUT/OUTPUT
**** CHARACTER PROCEDURE lookahead(fileref);
REF(Infile COMMENT or Directfile;) fileref;
Returns the next non-blank character value which would have
been the result of inchar. IF lastitem THEN result will be
blank;
INSPECT fileref DO
BEGIN
IF lastitem THEN lookahead:= ' ' ELSE
BEGIN lookahead:= inchar; setpos(pos-1);
END;
END;
**** PROCEDURE outline(t,out_file); VALUE t;
TEXT t; REF (outfile) out_file;
OUTLINE will output the argument text as one or more lines
on the output device. Protected against errors when the
parameter text is longer than the image.
INSPECT out_file DO
BEGIN
WHILE t.length > length DO
BEGIN
outtext(t.sub(1,length));
t:- t.sub(length+1,t.length-length);
outimage;
END;
outtext(t);
outimage;
END;
**** PROCEDURE breakoutline(t,out_file); VALUE t;
TEXT t; REF (outfile) out_file;
Same as OUTLINE, but does not output any new line indication
(<CR><LF> on ASCII terminals) before and after the text.
INSPECT out_file DO
BEGIN
WHILE t.length > length DO
BEGIN
breakoutimage;
outtext(t.sub(1,length));
t:- t.sub(length+1,t.length-length);
END;
outtext(t);
breakoutimage;
END;
DECsystem-10 SIMULA Language Handbook, part III Page 88
5.4 INPUT/OUTPUT
**** TEXT PROCEDURE inline(question,inf); NAME question;
TEXT question; REF (infile) inf;
Returns a stripped copy of a new INF input line
after displaying QUESTION on Sysout.
INSPECT (IF inf == NONE THEN Sysin ELSE inf) DO
BEGIN Sysout.Outtext(question);
Sysout.Breakoutimage; Inimage;
inline:- Copy(Image.Strip);
Setpos(0);
END;
**** TEXT PROCEDURE request
(prompt,default,result,valid,errmessage,help);
NAME prompt,default,result,valid,errmessage,help;
TEXT prompt,default,result,errmessage,help;
BOOLEAN valid;
Procedure REQUEST may be used when putting simple questions
to an interactive user. The PROMPTing question and the
DEFAULT value will be displayed on the user's terminal
(SYSOUT). The Stripped input line from the terminal (SYSIN)
is stored in RESULT. If then the NAME parameter VALID is
TRUE the result is accepted and (also) returned through
REQUEST. Otherwise the ERRMESSAGE is displayed followed by
a new PROMPTing question. If the user enters an empty
answer - i.e. presses the return key - the DEFAULT answer
will be used. (This may be prohibited by using an illegal
answer for default.) If the user enters a question mark '?',
the text HELP will be printed. Since it is a NAME
parameter, actual parameter may be a text procedure call
with the possible side effect of displaying additional help
text.
Since it may be difficult the remember the different
parameters - learn the following sentence: Please ( P for
Prompt) Don't (D for Default) Risk (R for Result) Villainous
(V for Valid) Entries (E for Errmessage) Here (H for Help).
Example:
!BEGIN EXTERNAL TEXT PROCEDURE conc,request,rest;
! EXTERNAL REF (Infile) PROCEDURE findinfile;
! EXTERNAL INTEGER PROCEDURE checkreal;
!
! TEXT u; REAL x;
!
! request("File:",NOTEXT,u,
! findinfile(u)=/=NONE,conc("? Can't find:",u),
! "Enter valid file spec for input file.");
!
! x:=
! request("Enter x:","2.5",u,
! checkreal(u) = 1 AND rest(u).Strip == NOTEXT,
DECsystem-10 SIMULA Language Handbook, part III Page 89
5.4 INPUT/OUTPUT
! "?Illegal real item.","Enter valid real item").Getreal;
!
!END
! For more frequent applications it is recommended to use
! a special validity testing Boolean procedure with the
! side-effect of saving (the finally correct) result.
! I.e.
! EXTERNAL TEXT PROCEDURE rest,request;
! EXTERNAL LONG REAL PROCEDURE scanreal;
!
! BOOLEAN PROCEDURE testreal(u,x);
! NAME x; TEXT u; REAL x;
! BEGIN INTEGER p;
! p:= u.Pos; x:= scanreal(u);
! testreal:= IF u.Pos > p THEN rest(u).Strip == NOTEXT
! ELSE FALSE;
! END of testreal;
!
! request("Enter x:","2.5",u,testreal(u,x),
! "?Illegal real item.","Enter valid real item");
TEXT PROCEDURE request
(prompt,default,result,valid,errmessage,help);
NAME prompt,default,result,valid,errmessage,help;
TEXT prompt,default,result,errmessage,help;
BOOLEAN valid;
BEGIN TEXT t;
GO TO start;
WHILE NOT valid DO
BEGIN
Outtext(errmessage); Outimage;
start:
Outtext(prompt);
IF default =/= NOTEXT THEN
BEGIN Outchar('/'); Outtext(default);
Outchar('/'); Outchar(':')
END;
Breakoutimage; Inimage;
t:- Copy(Sysin.Image.Strip); Sysin.Setpos(0);
IF t == NOTEXT THEN result:- Copy(default) ELSE
IF t.Getchar = '?' THEN
BEGIN Outtext(help); Outimage;
GO TO start
END ELSE
BEGIN t.Setpos(1); result:- t END;
END loop;
request:- result
END of request;
DECsystem-10 SIMULA Language Handbook, part III Page 90
5.4 INPUT/OUTPUT
**** PROCEDURE outtime(file,time,unit,secdec,fieldwidth);
REAL time; CHARACTER unit; INTEGER secdec,fieldwidth;
REF (Outfile) file;
Prints the variable TIME on the outfile FILE according
to PUTTIME format. C.f. procedure PUTTIME.
EXTERNAL PROCEDURES required:
TEXT PROCEDURE putfloat, puttime;
**** PROCEDURE histp(a,lowerbound,upperbound,yscale,
max,min,brick,xlabels,title,pf);
NAME title,xlabels; VALUE brick;
INTEGER ARRAY a;
INTEGER lowerbound,upperbound,yscale,max,min;
TEXT brick,xlabels,title; REF (Outfile) pf;
Procedure HISTP prints a histogram of the INTEGER ARRAY A
[LOWERBOUND:UPPERBOUND] on file PF.
YSCALE is the increment for the y axis (Integer > 0).
MAX is the maximum y value displayed (INTEGER).
MIN is the minimum y value displayed (INTEGER).
BRICK is a text which will be used when printing histogram
"piles" (TEXT by VALUE).
XLABELS is a text that will be printed at the bottom of the
histogram. If XLABELS == NOTEXT the indices LOWERBOUND and
UPPERBOUND will be printed. The start of the text will be
at the first "brick" character of the first "pile".
TITLE is a text that will be printed at the top of the
histogram.
PF is the output file. If PF is a PRINTFILE, HISTP will
start by calling EJECT(1).
Please note the following HISTP properties:
1. If MAX < MIN, the MAX and MIN values will be adjusted if
necessary (individually!). Thus, if MAX = -1 and MIN =
0 an array A with only positive elements will be
presented in a histogram with y axis range [0:max of A].
2. If (resulting) MIN is zero, this level will be indicated
by the x axis (----).
3. If BRICK starts with a blank, a single space between
"piles" will be printed.
4. IF PF == NONE, Sysout will be used.
5. IF the range [LOWERBOUND:UPPERBOUND] in combination with
DECsystem-10 SIMULA Language Handbook, part III Page 91
5.4 INPUT/OUTPUT
actual BRICK.LENGTH cannot be printed on one page
regarding current PF.Length, then the rest (the
rightmost part) of the histogram will be printed on a
subsequent page.
An example:
Input:
A[0:6]:= 5 -3 -1 0 3 4 2
YSCALE:= 1
MAX:= -10
MIN:= 10
BRICK:= " ***"
XLABELS:= " A B C D E F G"
TITLE:= "Test example - histogram print"
PF:- NONE
will produce the following output on SYSOUT:
Test example - histogram print
5 ! ***
! *** ***
! *** *** ***
! *** *** *** ***
1 ! *** *** *** ***
!----------------------------
! *** ***
! ***
-3 ! ***
--+---+---+---+---+---+---+-
A B C D E F G
IF lowerbound > upperbound THEN
BEGIN Outtext("?HISTP Illegal Array Bounds"); Outimage
END
ELSE IF yscale <= 0 THEN
BEGIN Outtext("?HISTP Non-positive Y-scale element");
Outimage END
ELSE
BEGIN
INTEGER i,up,newupperbound,h2,
tempmax,tempmin,width,negscale;
TEXT axis;
width:= brick.Length;
axis:- Blanks(width);
WHILE axis.More DO axis.Putchar('-');
IF pf == NONE THEN pf:- Sysout;
IF max < min THEN
BEGIN tempmin:= tempmax:= a[lowerbound];
FOR i:= lowerbound+1 STEP 1 UNTIL upperbound DO
IF a[i] > tempmax THEN tempmax:= a[i] ELSE
DECsystem-10 SIMULA Language Handbook, part III Page 92
5.4 INPUT/OUTPUT
IF a[i] < tempmin THEN tempmin:= a[i];
IF max < tempmax THEN max:= tempmax;
IF min > tempmin THEN min:= tempmin;
END loop setting max and min;
h2:= (max+min)//2;
IF (upperbound - lowerbound + 1)*width + 15 > pf.Length
THEN
BEGIN newupperbound:= upperbound;
upperbound:= (pf.Length-15)//width + lowerbound - 1
END
ELSE newupperbound:= lowerbound - 1;
! That was checking histogram width;
INSPECT pf WHEN Printfile DO
BEGIN Eject(1); Setpos(14); Outtext(title);
Outimage; Eject(Line+2)
END
WHEN Outfile DO
BEGIN Setpos(14); Outtext(title);
Outimage; Outimage
END;
up:= ((h2-min)//yscale)*yscale + min;
IF up < h2 THEN up:= up + yscale; h2:= up;
up:= ((max-min)//yscale)*yscale + min;
IF up < max THEN up:= up + yscale;
pf.Outint(up,12); pf.Outtext(" !");
negscale:= - yscale;
FOR up:= up STEP negscale UNTIL min DO
IF NOT (up = min AND min = 0) THEN
BEGIN
IF up = h2 OR up = min THEN
BEGIN pf.Setpos(1); pf.Outint(up,12);
pf.Outtext(" !")
END
ELSE
BEGIN pf.Setpos(14); pf.Outchar('!') END;
IF up NE 0 THEN
BEGIN
FOR i:= lowerbound STEP 1 UNTIL upperbound DO
IF a[i] = up THEN pf.Outtext(brick) ELSE
IF a[i] > up EQV up >= 0 THEN pf.Outtext(brick)
ELSE pf.Setpos(pf.Pos+width);
END ne 0 ELSE
IF min < 0 THEN
BEGIN pf.Setpos(14); pf.Outchar('!');
FOR i:= lowerbound STEP 1 UNTIL upperbound DO
pf.Outtext(axis);
END zero axis;
pf.Outimage
DECsystem-10 SIMULA Language Handbook, part III Page 93
5.4 INPUT/OUTPUT
END print loop;
pf.Setpos(15);
FOR i:= lowerbound STEP 1 UNTIL upperbound DO
pf.Outtext(axis);
i:= (upperbound-lowerbound)*width+15+width//2;
IF width > 1 THEN
BEGIN
FOR h2:= 15+width//2 STEP width UNTIL i DO
BEGIN pf.Setpos(h2); pf.Outchar('+') END;
END;
pf.Outimage;
IF xlabels == NOTEXT THEN
BEGIN
pf.Outint(lowerbound,15+width//2);
IF i > pf.Length THEN i:= pf.Length - 4;
pf.Setpos(i-4); pf.Outint(upperbound,5);
END ELSE
BEGIN pf.Setpos(15); pf.Outtext(xlabels) END;
pf.Outimage;
IF newupperbound >= upperbound THEN
histp(a,upperbound+1,newupperbound,yscale,max,min,
brick,xlabels,title,pf);
END of histp;
DECsystem-10 SIMULA Language Handbook, part III Page 94
5.5 SORTING AND SUMMATION ETC.
5.5 SORTING AND SUMMATION ETC.
**** INTEGER PROCEDURE ilog(x); REAL x;
ilog:= IF x = 0 THEN 0 ELSE
Entier(Ln(Abs(x))/2.30258 509517)+1;
**** INTEGER PROCEDURE isum(ia,n);
INTEGER ARRAY ia; INTEGER n;
Procedure ISUM calculates the sum of the integer array IA:
IA[1] + ... + IA[N].
BEGIN INTEGER i,s;
OPTIONS(/A); COMMENT START ARRAY BOUND CHECKING;
s:= ia[1];
ia[n]:= ia[n];;
OPTIONS(/-A); COMMENT NO ARRAY BOUND CHECKING;
FOR i:= 2 STEP 1 UNTIL n DO s:= s + ia[i];
isum:= s
END of isum;
**** REAL PROCEDURE rsum(a,n); ARRAY a; INTEGER n;
Procedure RSUM calculates the sum of the array A:
A[1] + ... + A[N].
BEGIN INTEGER i; REAL s;
OPTIONS(/A); COMMENT START ARRAY BOUND CHECKING;
s:= a[1]; a[n]:= a[n];;
OPTIONS(/-A); COMMENT NO ARRAY BOUND CHECKING;
FOR i:= 2 STEP 1 UNTIL n DO s:= s + a[i];
rsum:= s
END of rsum;
**** LONG REAL PROCEDURE lsum(la,n);
LONG REAL ARRAY la; INTEGER n;
Procedure LSUM calculates the sum of the long real array LA,
LA[1] + ... + LA[N] (almost) preserving precision. Thus if
LA[1] = E30, LA[2] = 1 and LA[3] = -E30 the sum will be
correctly calculated to 1.
EXTERNAL Procedure required: INTEGER PROCEDURE intrea;
BEGIN INTEGER i,icell,high,low; LONG REAL s;
DECsystem-10 SIMULA Language Handbook, part III Page 95
5.5 SORTING AND SUMMATION ETC.
LONG REAL ARRAY cell[0:63];
OPTIONS(/A); COMMENT START ARRAY BOUND CHECKING;
la[n]:= la[n];
icell:= intrea(la[1])//8R4000000000;;
OPTIONS(/-A); COMMENT NO ARRAY BOUND CHECKING;
IF icell < 0 THEN icell:= -icell;
high:= low:= icell;
cell[icell]:= la[1];
FOR i:= 2 STEP 1 UNTIL n DO
BEGIN icell:= intrea(la[i])//8R4000000000;
! Store LA[I] in CELL [ Abs(exp-part of LA[I]) ];
! Thus E+MM and -E+MM will be accumulated in the
! same cell;
IF icell < 0 THEN icell:= -icell;
IF icell > high THEN high:= icell ELSE
IF icell < low THEN low:= icell;
cell[icell]:= cell[icell] + la[i];
END loop;
! Sum starting with small values;
FOR i:= low STEP 1 UNTIL high DO
s:= s + cell[i];
lsum:= s
END of lsum;
**** REAL PROCEDURE sigma2(mean,sum,a,n);
NAME mean,sum; REAL mean,sum;
ARRAY a; INTEGER n;
Real procedure SIGMA2 calculates the variance, mean value
and sum of a REAL ARRAY A, from A[1] to A[N]. Array A must
be declared before calling SIGMA2 and have a lower bound <=
1 and a upper bound >= N. Results are returned in -
SIGMA2 Variance
MEAN Mean value
SUM Sum
IF n > 0 THEN
BEGIN REAL s,s2,x; INTEGER i;
OPTIONS(/A); COMMENT START ARRAY BOUND CHECKING;
s:= a[1]; a[n]:= a[n];;
OPTIONS(/-A); COMMENT NO ARRAY BOUND CHECKING;
s2:= s^2;
FOR i:= 2 STEP 1 UNTIL n DO
BEGIN x:= a[i];
s:= s + x;
s2:= s2 + x^2;
END;
x:= 1/n;
DECsystem-10 SIMULA Language Handbook, part III Page 96
5.5 SORTING AND SUMMATION ETC.
sigma2:= (s2 - s^2*x)*x;
mean:= s*x;
sum:= s;
END of sigma2;
**** PROCEDURE sigmean(sigma2,mean,k,xk1);
NAME sigma2,mean,k; REAL sigma2,mean,xk1; INTEGER k;
Procedure SIGMEAN calculates new sigma2 (variance) and mean
value for a statistical material where the following
properties are known -
Old variance SIGMA2
Old mean value MEAN
Number of observations made before K
Value of new observation XK1
At return the following values are available -
New variance SIGMA2
New mean value MEAN
Number of observations (=K+1) K
An example:
! BEGIN
! EXTERNAL PROCEDURE sigmean;
! REAL sigma2,mean;
! INTEGER k;
! ....
! k:= 0;
! mean:= sigma2:= 0;
! ...
! WHILE ... DO
! BEGIN
! ... x:= <new observed value>;
! sigmean(sigma2,mean,k,x);
! END loop;
! ...
Note that some precision will be lost using SIGMEAN,
compared with the result of calculating the variance and
mean value from all the observations. However, since
SIGMEAN calculates the variance and mean value recursively,
there is no need to save all the earlier observations in an
array.
BEGIN REAL oldsigma2,oldmean,ik1,z; INTEGER oldk,k1;
oldsigma2:= sigma2;
oldmean:= mean;
oldk:= k;
k:= k1:= oldk + 1;
ik1:= 1.0/k1;
z:= (oldmean-xk1)*ik1;
DECsystem-10 SIMULA Language Handbook, part III Page 97
5.5 SORTING AND SUMMATION ETC.
mean:= xk1 + oldk*z;
sigma2:= oldk*(oldsigma2*ik1 + z^2);
END of sigmean;
The sorting procedures SORTTA, SORTTD, SORTIA, SORTID, SORTRA,
SORTRD, SORTLA, SORTLD may be coded as one external assembly
module accepting any kind of TEXT, [LONG] REAL or INTEGER
one-dimensional array.
**** PROCEDURE sortta (arr,n);
TEXT ARRAY arr; INTEGER n;
Procedure SORTTA will sort the contents of the TEXT array in
ASCENDING order. Author: Algorithm 271 CACM 11-65, 5-66.
Modified by: Mats Ohlin, FOA 1, S-104 50 STOCKHOLM 80,
SWEDEN.
BEGIN INTEGER i,k,q,m,p; TEXT t,x;
INTEGER ARRAY ut,lz [1:Ln(Abs(n)+2)/0.69314718];
OPTIONS(/A); COMMENT START ARRAY BOUND CHECKING;
IF arr[1] > arr[n] THEN
BEGIN ; OPTIONS(/-A);
t:- arr[1];
arr[1]:- arr[n]; arr[n]:- t
END test and swap;
i:= m := 1;
WHILE m > 0 DO
BEGIN
IF n-i > 1 THEN
BEGIN
p:= (n+i)//2; t:- arr[p];
arr[p]:- arr[i]; q:= n; k:= i;
FOR k:= k+1 WHILE k <= q DO
BEGIN
IF arr[k] > t THEN
BEGIN
WHILE q >= k DO
BEGIN
IF arr[q] < t THEN
BEGIN
x:- arr[k]; arr[k]:- arr[q];
arr[q]:- x; q:= q-1;
GO TO l;
END;
q:= q-1;
END Q;
END;
l:
END K;
arr[i]:- arr[q];
DECsystem-10 SIMULA Language Handbook, part III Page 98
5.5 SORTING AND SUMMATION ETC.
arr[q]:- t;
IF 2*q>i+n THEN
BEGIN
lz[m]:= i; ut[m]:= q-1;
i:= q+1;
END ELSE
BEGIN
lz[m]:= q+1; ut[m]:= n;
n:= q-1;
END;
m:= m+1;
END ELSE
BEGIN
IF (
IF i < n THEN arr[i] > arr[n] ELSE FALSE
) THEN
BEGIN
x:- arr[i]; arr[i]:- arr[n];
arr[n]:- x
END;
m:= m-1;
IF m > 0 THEN
BEGIN i:= lz[m]; n:= ut[m] END;
END
END m > 0 loop;
END SORTTEXT IN ASCENDING ORDER;
**** PROCEDURE sorttd (arr,n);
TEXT ARRAY arr; INTEGER n;
Procedure SORTTD will sort the contents of the TEXT array in
DESCENDING order. Author: Algorithm 271 CACM 11-65, 5-66.
Modified by: Mats Ohlin, FOA 1, S-104 50 STOCKHOM 80,
SWEDEN. Date: 75-09-19 ;
BEGIN INTEGER i,k,q,m,p; TEXT t,x;
INTEGER ARRAY ut,lz [1:Ln(Abs(n)+2)/0.69314718];
OPTIONS(/A); COMMENT START ARRAY BOUND CHECKING;
IF arr[1] < arr[n] THEN
BEGIN ; OPTIONS(/-A);
t:- arr[1];
arr[1]:- arr[n]; arr[n]:- t
END test and swap;
i:= m := 1;
WHILE m > 0 DO
BEGIN
IF n-i > 1 THEN
BEGIN
p:= (n+i)//2; t:- arr[p];
arr[p]:- arr[i]; q:= n; k:= i;
FOR k:= k+1 WHILE k <= q DO
BEGIN
IF arr[k] < t THEN
DECsystem-10 SIMULA Language Handbook, part III Page 99
5.5 SORTING AND SUMMATION ETC.
BEGIN
WHILE q >= k DO
BEGIN
IF arr[q] > t THEN
BEGIN
x:- arr[k]; arr[k]:- arr[q];
arr[q]:- x; q:= q-1;
GO TO l;
END;
q:= q-1;
END Q;
END;
l:
END K;
arr[i]:- arr[q];
arr[q]:- t;
IF 2*q>i+n THEN
BEGIN
lz[m]:= i; ut[m]:= q-1;
i:= q+1;
END ELSE
BEGIN
lz[m]:= q+1; ut[m]:= n;
n:= q-1;
END;
m:= m+1;
END ELSE
BEGIN
IF (
IF i < n THEN arr[i] < arr[n] ELSE FALSE
) THEN
BEGIN
x:- arr[i]; arr[i]:- arr[n];
arr[n]:- x
END;
m:= m-1;
IF m > 0 THEN
BEGIN i:= lz[m]; n:= ut[m] END;
END
END m > 0 loop;
END SORTTEXT IN DESCENDING ORDER;
**** PROCEDURE sortdn(arr,i1,n,key);
INTEGER ARRAY arr; INTEGER i1,n,key;
SORTDN sorts (a section of) the 2-dimensional array
ARR[2,nmax]. The segment ARR[*,I1] to ARR[*,N] is sorted
according to KEY in ascending order. KEY determines which
column to regard as primary sorting key, and whether to sort
also on the secondary key, thus:
KEY = 0: Sort first on ARR[1,*], then ARR[2,*].
KEY = 1: Only sort on ARR[1,*].
KEY = 2: Reverse of KEY = 1.
KEY = 3: Reverse of KEY = 0.
KEY < 0 or KEY > 3: as KEY = 0.
DECsystem-10 SIMULA Language Handbook, part III Page 100
5.5 SORTING AND SUMMATION ETC.
ARR[1,i] and ARR[2,i] are always moved as a unit (2 words).
SORTDN is a modification of SORTIA (q.v.), which is a
modification by Mats Ohlin, FOA, of Algorithm 271 CACM
11-65, 5-66. The SORTDN modification was made by Lars
Enderin, FOA, for the purpose of sorting UFD and SFD
directory files under TOPS-10.
**** REAL PROCEDURE scalestep(pmax,pmin,ptics);
NAME pmax,pmin,ptics; REAL pmax,pmin; INTEGER ptics;
Procedure SCALESTEP calculates values suitable for axis
design. PMAX is input max (rough) value and at return
increased justified max value. PMIN ditto decreased min
value. PTICS is number of increments along axis (Result
parm.) SCALESTEP is size of axis increment.
REAL PROCEDURE scalestep(pmax,pmin,ptics); NAME
pmax,pmin,ptics; REAL pmax,pmin; INTEGER ptics; BEGIN
REAL max,min,width,d; INTEGER n0,n1,pow;
max:= pmax; min:= pmin;
width:= Abs(max - min); IF width NE 0 THEN BEGIN
WHILE width > 10 DO BEGIN width:= width*0.1;
pow:= pow + 1 END; WHILE width <= 1 DO BEGIN
width:= width*10; pow:= pow - 1 END;
! Normalize width ; IF width NE Entier(width)
THEN width:= IF width > 8 THEN 10 ELSE IF width >
1.5 THEN Entier(width+1) ELSE IF width > 1.25 THEN 1.5
ELSE 1.25;
! Calculate normalized increment ; d:= IF width
>= 8.0 THEN 2 ELSE IF width > 3.5 THEN 1 ELSE IF width
> 1.6 THEN 0.5 ELSE 0.25;
! Now scale normalized increment d ; WHILE pow >
0 DO BEGIN d:= d*10; pow:= pow - 1 END; WHILE pow <
0 DO BEGIN d:= d*0.1; pow:= pow + 1 END;
! Calculate number of increments ; n1:=
Entier(max/d); IF n1*d < max THEN n1:= n1 + 1;
n0:= Entier(min/d);
ptics:= n1 - n0;
pmax:= n1*d; pmin:= n0*d;
scalestep:= d;
END width NE 0;
DECsystem-10 SIMULA Language Handbook, part III Page 101
5.5 SORTING AND SUMMATION ETC.
END of scalestep;
**** BOOLEAN PROCEDURE
iashift(a,destindex,fromindex,length,zero); INTEGER ARRAY
a; INTEGER destindex,fromindex,length; BOOLEAN zero;
IASHIFT moves LENGTH elements of the INTEGER ARRAY A,
starting at FROMINDEX, to DESTINDEX. FROMINDEX must be >=
DESTINDEX. If ZERO is TRUE, then remaining elements to the
right of DESTINDEX+LENGTH-1 will be zeroed. Thus,
IASHIFT(A,1,1,0,TRUE) will make all elements in the array
A[1:xx] zero.
IASHIFT will return TRUE if the operation was successful -
illegal parameters will cause IASHIFT to return FALSE.
Assuming accessibility of the lower and upper bounds of the
array the code would be:
IF destindex >= a.lower AND destindex <= a.upper AND
fromindex >= destindex AND fromindex+length <= a.upper+1
THEN
BEGIN INTEGER i;
IF destindex NE fromindex THEN
FOR i:= 1 STEP 1 UNTIL length DO
BEGIN a[destindex]:= a[fromindex];
destindex:= destindex + 1;
fromindex:= fromindex + 1;
END i loop ELSE
destindex:= destindex + 1;
IF zero THEN
! Zero the rest of a.
! Destindex now = next after last moved element;
FOR i:= destindex STEP 1 UNTIL a.upper DO
a[i]:= 0;
iashift:= TRUE
END of iashift;
**** INTEGER PROCEDURE imax(i1,i2); INTEGER i1,i2;
COMMENT IMAX will replace the calling code by inline code;
imax:= IF i1 > i2 THEN i1 ELSE i2;
**** INTEGER PROCEDURE imin(i1,i2); INTEGER i1,i2;
COMMENT IMIN will replace the calling code by inline code;
imin:= IF i1 < i2 THEN i1 ELSE i2;
DECsystem-10 SIMULA Language Handbook, part III Page 102
5.6 RANDOM NUMBER GENERATION ETC.
5.6 RANDOM NUMBER GENERATION ETC.
**** PROCEDURE SCRAMBLE(ia,bottom,top,u); NAME u; INTEGER ARRAY
ia; INTEGER bottom, top, u;
The INTEGER ARRAY ia is permuted randomly in the interval
bottom, top. The parameter u is the random number seed.
**** CLASS PERGEN(a,n); INTEGER ARRAY a; INTEGER n;
CLASS PERGEN generates all the possible permutations of the
contents in INTEGER ARRAY a[1:N], one at a time.
Use:
REF (pergen) pg;
pg:- NEW pergen(a,n);
WHILE pg.cycles < 2 DO
BEGIN Call(pg); ! use new permutation END;
Note that N Must be >= 2. Also observe that permutations
are generated systematically and that the order will be
REVERSED when one N! cycle is completed. Thus for N = 2
then result will be (if A[1]=1, A[2]=2 initially):
(1 2) (2 1) (2 1) (1 2) (1 2) (2 1) etc.
The permutations will be generated in such manner that the
last elements of A will change most slowly. The attribute
CYCLES will indicate to which cycle the NEXT permutation
will belong (after next Call that is).
Ref:"Generation of permutation sequences", A.D. Woodall,
The Computer Journal vol 20, No 4 1977 p 346.
Modified by: Mats Ohlin, FOA, Stockholm, Sweden.
For random permutations see procedure SCRAMBLE.
External procedure required: IMAX
CLASS pergen(a,n); INTEGER ARRAY a; INTEGER n;
BEGIN
INTEGER p,mp,swpt,i,w,cycles;
INTEGER ARRAY m,km[2:imax(3,n)],
ret[2:imax(2,n)];
IF n < 2 THEN
BEGIN
Outtext("%PERGEN - 2nd parm N must be >= 2");
Outimage;
END ELSE
BEGIN
OPTIONS(/A);
a[1]:= a[1]; a[n]:= a[n];
km[n]:= ret[n]:= km[2]:= ret[2];;
OPTIONS(/-A);
DECsystem-10 SIMULA Language Handbook, part III Page 103
5.6 RANDOM NUMBER GENERATION ETC.
FOR i:= 4 STEP 2 UNTIL n DO
BEGIN p:= i-1;
km[i]:= p; km[p]:= 2-i;
END i loop;
GO TO run;
start: Detach; run:
cycles:= cycles + 1;
FOR i:= 2 STEP 1 UNTIL n DO ret[i]:= i+1;
FOR i:= 4 STEP 2 UNTIL n DO
BEGIN m[i]:= i-1; m[i-1]:= 2-i
END i loop;
IF Mod(n,2) NE 0 THEN m[n]:= 1-n;
loop: p:= ret[2];
IF p > 3 THEN ret[2]:= 3;
Detach;
w:= a[1]; a[1]:= a[2]; a[2]:= w;
IF p > n THEN GO TO start;
mp:= m[p];
IF mp < 0 THEN
BEGIN swpt:= 1; mp:= mp+1 END ELSE
BEGIN swpt:= mp; mp:= mp-1 END;
IF mp = 0 THEN
BEGIN
m[p]:= km[p];
ret[p-1]:= ret[p]; ret[p]:= p+1
END ELSE m[p]:= mp;
Detach;
w:= a[p]; a[p]:= a[swpt]; a[swpt]:= w;
GO TO loop;
END n >= 2
END of pergen;
**** REAL PROCEDURE RANDOM(a,b); REAL a,b;
Returns an uniformly distributed value in the interval (a,b)
(c.f. FORTRAN routine random).
**** INTEGER PROCEDURE UNIQUE
UNIQUE will return increasing integer numbers.
The returned value will increase with one each jiffy
(1/50 or 1/60 second).
The returned value is a number in which bits 1-11 contain
the day number since 1977-01-01 (mod 4096) and bits 12-35
contain time of day in jiffies.
The sequence will restart (from zero) every 4096th day
(11 years and 81 days).
DECsystem-10 SIMULA Language Handbook, part III Page 104
5.6 RANDOM NUMBER GENERATION ETC.
EXTERNAL PROCEDURE required: INTEGER PROCEDURE gettab;
BEGIN
! Take daynumber after 1977-01-01, put it into bits 0-11
! and add no. of jiffies (always < 2^23);
! 262144 = 2^18 8388608 = 2^23;
unique:=
Mod(gettab(9,43)//262144-43144,4096)*8388608
+ gettab(9,8);
END of unique;
**** INTEGER PROCEDURE nextrandom(n,u);
INTEGER n,u;
Returns the N:th successor to U in the random number
sequence used by the random generator in the DECsystem-10
SIMULA system. N may be negative. (Ref: SIMULA Newsletter
Vol 5(2), may 1977)
DECsystem-10 SIMULA Language Handbook, part III Page 105
5.7 SIMULA VERSIONS OF SYSTEM CLASSES
5.7 SIMULA VERSIONS OF SYSTEM CLASSES
**** ZIMSET and ZIMULATION
ZIMSET and ZIMULATION are two SIMULA classes which include
simple tracing facilities. They may be used for educational
as well as debugging purposes.
For complete documentation, see FOA Report C10055-M3(E5),
October 1976, distributed as ZIMULA.MAN.
A small example:
BEGIN
EXTERNAL PROCEDURE abort;
EXTERNAL TEXT PROCEDURE upcase, conc, puttime,
putfloat, today, daytime;
EXTERNAL CLASS zimset,zimulation;
zimulation BEGIN
process CLASS a; Passivate;
traceon("Trace.Log","*");
! Start trace on TRACE.LOG;
setparms('M',0);
! Time format: Minutes, no decimal seconds;
activat(NEW a,"DELAY",5,NONE);
! ACTIVATE NEW a DELAY 5;
activat(NEW a,"AT",8,NONE);
! ACTIVATE NEW a AT 8;
hold(2);
sqslist;
reactivat(current,"AT",10,NONE);
! REACTIVATE Current AT 10;
prior_:= TRUE; activat(NEW a,"AFTER",0,NEW a);
! ACTIVATE NEW a AFTER NEW a PRIOR;
END zimulation
END of program
will produce the following output on TRACE.LOG:
*** Trace generated 1976-10-13 at 12:20:35 *** Trace Codes: All
00:00.00 ( 2) will be Delayed to 00:05.00
( 3) will be ACT. AT 00:08.00
Main Program Held 00:02.00 to 00:02.00
:---- Scheduled Processes ----
: Evtime Title
: 00:02.00 Main Program
DECsystem-10 SIMULA Language Handbook, part III Page 106
5.7 SIMULA VERSIONS OF SYSTEM CLASSES
: 00:05.00 ( 2)
: 00:08.00 ( 3)
:---- End of SQS List --------
00:02.00 Main Program will be ACT. AT 00:10.00
Main Program was REACT. from 00:02.00
00:05.00 ( 2) Passivated
00:08.00 ( 3) Passivated
? 00:10.00 ( 4) Pass. due to ACT. AFTER Idle ( 5)
DECsystem-10 SIMULA Language Handbook, part III Page 107
6. SWEDISH LANGUAGE TEXT HANDLING AND INPUT/OUTPUT
6. SWEDISH LANGUAGE TEXT HANDLING AND INPUT/OUTPUT
-----------------------------------------------
NOTE: Some of these routines are not yet written. See the list
in chapter 0.2, which indicates which routines are not
available.
The difference between English and Swedish text handling is
that the national Swedish letters $(=AA), #(=AE), @(=OE) (in
lower case }(=aa), {(=ae), `(=oe)) are regarded as letters.
In addition, underline (_) is regarded as part of an
identifier (like a digit in this context).
This table gives the names of Swedish procedures
corresponding to English procedure described above.
ENGLISH SWEDISH
**** LETTER BOKSTAV
**** LOWCASE LITENBOKSTAV
**** MENU MENY
**** UPCASE STORBOKSTAV
**** GETITEM TAGORD
**** INITEM INORD
**** GETTYPE TAGTYP
DECsystem-10 SIMULA Language Handbook, part III Page 108
7. UTILITIES SPECIFIC TO DECSYSTEM-10
7. UTILITIES SPECIFIC TO DECSYSTEM-10
----------------------------------
The utilities in this section are intended for specialized
use. If you want to write portable programs, you should
avoid them, since special hardware or software features are
explicitly used, e.g. a 36-bit word is assumed.
**** INTEGER PROCEDURE absadr;
Takes a variable of any type as parameter. Illegal
parameters will give a returned value = 0.
- If the variable is a SIMPLE variable (not an array) of
type INTEGER, REAL, LONG REAL, CHARACTER or BOOLEAN, the
address of the first word of the value is returned.
- If it is a REF variable, a copy of the value is returned,
i e the address of the object or the value of NONE (an
illegal address).
- ABSADR of a TEXT variable returns a standard byte pointer
to the character BEFORE the first character (7-bit byte) of
the text value. If t="ABC",
LOADBYTE(ABSADR(t),1)=Rank('A'). See LOADBYTE, STOREBYTE,
ADJPTR.
- ABSADR of an ARRAY is the address of the array object.
See [LH2] appendix B for the format of class instances
(objects) and arrays. This procedure is intended for highly
implementation- and machine-dependent applications. Be very
careful not to cause a garbage collection between
computation of an absolute address and its use!
**** INTEGER PROCEDURE adjptr(bp,n);
INTEGER bp,n;
Adjusts the standard byte pointer BP by N bytes using the
ADJBP instruction (KL-10/20 processors only, not KA-10 or
KI-10). See hardware documentation.
**** INTEGER PROCEDURE andint(x,y);
INTEGER x,y;
Performs bitwise AND function of X,Y. Example:
ANDINT(2R1010111,2R1001110)=2R1000110.
DECsystem-10 SIMULA Language Handbook, part III Page 109
7. UTILITIES SPECIFIC TO DECSYSTEM-10
**** CLASS atrstr;
ATRSTR implements a data structure and procedures which map
the structure of an attribute file for an external class or
procedure. A structure is set up by calling the load
procedures of the various component classes, taking
information from an ATR file. If the file is a library
file, the modules can be found and mapped one after the
other. Subclasses of ATRSTR can be used e.g. to display the
structure as pseudo-SIMULA code (see SIMATR).
**** INTEGER PROCEDURE bitfield(w,firstbit,len);
INTEGER w,firstbit,len;
Returns the byte of word W starting at FIRSTBIT,
(0 <= FIRSTBIT <= 35) of length L bits, where L=Abs(LEN).
L>=0 AND L<36 AND FIRSTBIT+L<=36 must hold.
Special option: If LEN < 0, the first bit is regarded as a
sign bit and extended.
Examples: Assume w = 8r123456 701234. Then
bitfield(w,9,12) = 8r4567, and
bitfield(w,9,-12)=8r777777 774567. The prefix 8r means
octal radix.
**** BOOLEAN PROCEDURE bitget(w,n);
INTEGER w,n;
TRUE if bit 36-n in w is 1;
**** PROCEDURE bitput(w,n,b);
INTEGER w,n; BOOLEAN b;
Bit 36-n of w := IF b THEN 1 ELSE 0;
DECsystem-10 SIMULA Language Handbook, part III Page 110
7. UTILITIES SPECIFIC TO DECSYSTEM-10
**** INTEGER PROCEDURE boolfunc(f,x,y);
INTEGER f,x,y;
Computes one of the 16 possible Boolean functions of two
variables. The operation is performed on corresponding bits
in X and Y. The function is defined by F (0<=F<=15, taken
modulo 16 if not in range).
The following functions are defined:
F x 0101
y 0011
-----------------------------------
0 0000 FALSE
1 0001 x AND y
2 0010 (NOT x) AND y
3 0011 y
4 0100 x AND (NOT y)
5 0101 x XOR y
6 0110 x OR y
7 0111 x OR y
8 1000 NOT (x OR y) "NOR"
9 1001 x EQV y
10 1010 NOT x
11 1011 x IMP y (NOT x OR y)
12 1100 x OR (NOT y)
13 1101 NOT (x OR y)
14 1110 NOT (x AND y) "NAND"
15 1111 TRUE
-----------------------------------
Example: BOOLFUNC(4,5,3)=4 (actually, BOOLFUNC(n,5,3)=n
always).
**** INTEGER PROCEDURE callmic(micfile,savfile);
VALUE micfile,savfile; TEXT micfile,savfile;
PROCEDURE CALLMIC will enable the SIMULA programmer to do
almost anything from his (her) SIMULA program. The use of
this procedure depends on the existence of the Hatfield MIC
system residing on the SYS: area.
The procedure CALLMIC is used in the following manner -
The user first creates a file MIC.TMP containing ordinary
DEC-10 commands like .DELETE *.BAK
.RUN ABC
.COJOB=A.MIC parm1
.DO ABCMIC
etc.
The call CALLMIC("MIC.TMP","SAV.TMP"); will then use
MIC.TMP for a MIC run.
DECsystem-10 SIMULA Language Handbook, part III Page 111
7. UTILITIES SPECIFIC TO DECSYSTEM-10
The files MICFILE,SAVFILE will - if possible - be deleted at
return.
If the file name for the MIC file contains a protection code
with 1st digit equal to 2 (i.e. "MIC.TMP<277>"), then the
MIC execution will be silent. Note, however, that CALLMIC
will be unable to delete the file afterwards. (The message
"? MACRO FILE NOT FOUND." will follow at the end of the
SIMULA program. Please ignore that message.) Alternatively
the user may start the MIC file with: .SILENCE
If the 2nd parameter =/= NOTEXT the MIC session will end by
returning to the point of CALLMIC call: CALLMIC will save
current program in file SAVFILE and end the MIC session with
.RUN "SAVFILE".
Otherwise, if SAVFILE == NOTEXT, no return to the calling
program will occur.
!!!! The same restrictions as for SAVE are valid. Thus:
!!!! Only Sysin and Sysout may be open.
!!!! Sysin and Sysout must be the user's TTY.
Note that you may close Outfiles before calling CALLMIC and
then open again with "file.ext/access:append". Infiles are
more difficult to handle - you may keep count of how many
lines you have read before closing and then read past the
part already read after opening again. Directfiles give no
problems here of course - just save current Location, close
and open again after return from CALLMIC.
A small user example:
!BEGIN
! EXTERNAL PROCEDURE run;
! EXTERNAL BOOLEAN PROCEDURE scratchfile,tmpout;
! EXTERNAL INTEGER PROCEDURE save,callmic;
! EXTERNAL TEXT PROCEDURE inline,conc,tmpnam;
! INTEGER rc;
! TEXT micfile,savfile;
! micfile:- inline("Mic file name:",Sysin);
! IF micfile == NOTEXT THEN micfile:- Copy("Mic.tmp");
! savfile:- inline("Sav file:",Sysin);
! Outtext("End with extra CR");
! Outimage;
! INSPECT NEW Outfile(micfile) DO
! BEGIN
! Open(Sysin.Image);
! ! Note the neat way of copying input lines
! ! from Sysin to MICFILE.;
DECsystem-10 SIMULA Language Handbook, part III Page 112
7. UTILITIES SPECIFIC TO DECSYSTEM-10
! WHILE inline("Command:",Sysin).Strip =/= NOTEXT DO
! Outimage;
! Close
! END micfile creation;
! rc:= callmic(micfile,savfile);
! Outtext("Return code:");
! Outint(rc,5);
! Outimage;
!END of program
EXTERNAL PROCEDURES required:
BOOLEAN PROCEDURE scratchfile; PROCEDURE run;
INTEGER PROCEDURE save; TEXT PROCEDURE tmpnam,conc,tmpout;
IF micfile =/= NOTEXT THEN
BEGIN INTEGER returncode; TEXT cmdfile;
tmpout("MIC",conc("/",micfile));
IF savfile =/= NOTEXT THEN
BEGIN
INSPECT
NEW Outfile(conc(micfile,"/ACCESS:APPEND")) DO
BEGIN Open(Blanks(40));
Outtext(".REVIVE .RUN ");
Outtext(savfile); Close
END add sav file name;
returncode:= save(savfile,TRUE);
IF returncode = 0 THEN
run("SYS:MIC",2) ELSE
IF returncode < 0 THEN
BEGIN Outtext("? Save failed with filename:");
Outtext(savfile); Outimage
END ELSE
scratchfile(savfile);
END savfile =/= notext ELSE run("SYS:MIC",2);
scratchfile(micfile);
scratchfile(tmpnam("MIC"));
scratchfile(cmdfile);
stop: callmic:= returncode;
END of callmic;
DECsystem-10 SIMULA Language Handbook, part III Page 113
7. UTILITIES SPECIFIC TO DECSYSTEM-10
**** TEXT PROCEDURE checkextension(t,defaultextension);
VALUE defaultextension; TEXT t,defaultextension;
CHECKEXTENSION may be used to add a default extension to
file specifications not containing a dot ('.'). I.e.
! T:- Copy("A");! T:- checkextension(T,".SIM");
! will give T the value "A.SIM", while
! T:- Copy("A.");! T:- checkextension(T,".SIM");
! will leave T unaltered.
! T:- Copy("LPT:");! T:- checkextension(T,".SIM");
! will leave T unaltered.
! T:- Copy("LPT: A");! T:- checkextension(T,".SIM");
! will give T the value "LPT: A.SIM".
;
EXTERNAL PROCEDURES required:
CHARACTER PROCEDURE findtrigger;
TEXT PROCEDURE conc,rest;
IF t =/= NOTEXT THEN
BEGIN t.Setpos(1);
IF findtrigger(t,Copy(":")) NE ':' OR
rest(t).Strip =/= NOTEXT THEN
BEGIN t.Setpos(1);
IF findtrigger(t,Copy(".")) NE '.' THEN
t:- conc(t,defaultextension) ELSE t.Setpos(1);
END;
checkextension:- t
END of checkextension;
**** INTEGER PROCEDURE depbyte(val,w,firstbit,len);
INTEGER val,w,firstbit,len;
Returns the value of W with the modification:
The byte starting at FIRSTBIT (0-35) of length LEN bits is
replaced by VAL. LEN>=0 AND LEN<=36 AND FIRSTBIT+LEN<=36
must hold. Note: The last LEN bits of VAL will be used,
the other bits will be ignored.
**** CLASS dirhnd
DIRHND contains data structures which can be loaded with
information from TOPS-10 directory files (UFD and SFD
files). The procedure LOADSELECTEDFILENAMES can be used to
read this information, selecting certain file names
according to a wild card pattern (see MATCH6, WILDSIX).
LOADSELECTEDFILENAMES is an attribute of CLASS
DIRECTORYPATH, which is declared inside DIRHND and contains
information defining the directory file. The directory
information is placed in objects of class DIRECTORYBLOCK,
DECsystem-10 SIMULA Language Handbook, part III Page 114
7. UTILITIES SPECIFIC TO DECSYSTEM-10
which are reached via objects of FILENAMELIST class
SIXBITFILENAMELIST. DIRHND is only rudimentary at present
and CANNOT BE USED on DECsystem-20 (TOPS-20).
**** PROCEDURE echo(fileref,mode); REF(Infile)fileref; INTEGER
mode;
Provided fileref refers to a TTY file, different values of
mode have the following effects:
mode=0 resets the mode to normal.
mode=1 sets special editor mode.
mode=2 suppresses echoing on the terminal completely.
mode=4 causes all characters to echo exactly as typed.
Combinations are possible where meaningful, i e 5=4+1.
No effect on other files.
**** INTEGER PROCEDURE filcopy(source,dest);
REF(Infile)source; TEXT dest;
Copies the SOURCE file to the (new) file specified by the
text DEST, which is a normal DECsystem-10 (or -20) file
specification acceptable to the SIMULA run time system. A
NEW Outfile(dest) is created, and the contents of source are
copied to the new file buffer by buffer (using TOPS-10 I/O,
thus the PA1050 compatibility must be used under TOPS-20).
!!! ONLY DISK FILES are handled !!!
FILCOPY copies the file without changing the creation date
as ordinary SIMULA code would do, and does it rather
efficiently without using Image. The disk space allocation
is taken from the source file lookup data, minimizing
fragmentation. If a long file is copied, it may be useful
to allocate more than 2 standard buffers for each file
(/BUFFERS switch).
FILCOPY returns -1 on success, 0 otherwise (or 2 if one of
the files is not a disk file).
DECsystem-10 SIMULA Language Handbook, part III Page 115
7. UTILITIES SPECIFIC TO DECSYSTEM-10
**** INTEGER PROCEDURE flokup(f);
INTEGER f;
F contains the address of a control block suitable for the
FILOP. UUO (See Monitor Calls). The .FOLEB field must
contain a pointer to a lookup block (ordinary 4-word block
or an extended lookup block). FLOKUP looks up the file
given by the lookup block and also determines the exact path
of the file (placed in the PATH. block pointed to by the
.FOPAT field). On entry, the FILOP. block must contain i/o
channel number in .FOFNC(F), SIXBIT device name in
.FODEV(F), i/o mode in .FOIOS(F), addresses of PATH. and
lookup blocks in .FOPAT(F), .FOLEB(F). The lookup block
must contain information (path, filename and extension in
sixbit) for finding the file. If the file can be found, the
value of FLOKUP=F and the various blocks are updated,
otherwise the value FLOKUP=0 is returned.
WARNING: FLOKUP should only be used in special cases when
the ordinary SIMULA i/o procedures are inadequate.
**** TEXT PROCEDURE filspc(fileref,format);
REF(FILE)fileref; INTEGER format;
Returns a string specifying a file:
in TOPS-10: dev:file.ext[path]<prot>
in TOPS-20: str:<directory>file.ext;Pnnnnnn
FORMAT is an integer which specifies the fields to be
included in the resulting string. FORMAT is basically
treated as a packed integer array, where most elements are 3
bits wide. Each 3-bit integer controls one field of the
output string. The value of a controlling integer can be:
0: Suppress the field. 1: Always output the field.
2: Suppress the field if it is the system default.
The following octal values would be used to always output
the corresponding fields:
8R 100000 000000 (2^33) Output DEVICE (File structure)
8R 010000 000000 (2^30) Directory name in TOPS-20, ppn
(+SFD) path in TOPS-10
8R 001000 000000 (2^27) File name (value=2 illegal)
8R 000100 000000 (2^24) File type (extension) (value=2
illegal)
8R 000010 000000 (2^21) File generation number (not
implemented)
8R 000001 000000 (2^18) Protection
8R 000000 040000 (2^14, one bit) Temporary file (only in
TOPS-20)
The remaining field control bits used are:
8R 000000 000001 (2^0) Punctuate All Fields, e g
DEV:NAME.EXT[p,pn,sfd1,sfd2] The format is adapted from the
control word for the JFNS JSYS in TOPS-20 (see the Monitor
DECsystem-10 SIMULA Language Handbook, part III Page 116
7. UTILITIES SPECIFIC TO DECSYSTEM-10
Calls manual for TOPS-20) to make it easy to modify when and
if full TOPS-20 support will be included in the SIMULA
system. FORMAT=0 or omitted is equivalent to
8R 221110 000001 -
dev:name.ext[proj,prog,sfd1,...] (TOPS-10)
dev:<directory>name.typ.gen;T (TOPS-20)
with dev: omitted if it is DSK, <directory> omitted if it
is the connected directory, [proj,...] omitted if it is the
default path.
Requires the external module FILEST (entry .FILST).
**** INTEGER PROCEDURE gettab(table,index);
INTEGER table,index;
Executes GETTAB ac, where ac is [index,,table]. See Monitor
Calls Manual.
**** TEXT PROCEDURE idrx50(w); INTEGER w;
Converts bits 4-35 of W to a RADIX50 identifier text
(Length=6). Bits 0-3 are
1) stored in idrx50.Main.Sub(1,1) directly,
2) Converted to octal (after appending 2 zero bits to the
right) in idrx50.Main.Sub(2,3), where the last char is
blank.
The following relation holds:
idrx50.Main.Sub(5,6) == idrx50.
Example: Octal 123456701234 is converted to "?10 OQ5H%3",
where ? stands for Char(8r10//4) = Char(2) (=^B).
**** TEXT PROCEDURE idsixbit(id6a,id6b);
INTEGER id6a,id6b;
Converts the two words id6a,id6b to a 12-character text
(ASCII). The result is Strip of this identifier. If only 6
or fewer characters are relevant, use zero as second
parameter.
DECsystem-10 SIMULA Language Handbook, part III Page 117
7. UTILITIES SPECIFIC TO DECSYSTEM-10
**** INTEGER PROCEDURE intrea(x); REAL x;
Provides type conversion REAL to INTEGER. The real x is
interpreted as an integer quantity with the same bit
pattern. Use with care - highly machine dependent!
**** INTEGER PROCEDURE jobstatus(f);
REF(Infile)f;
Returns the job status for a TTY or PTY associated with the
file object F. See PTYCHECK for interpretation of the value
returned.
**** INTEGER PROCEDURE loadbyte(bp,incr);
INTEGER bp,incr;
Load a byte via the standard byte pointer BP, modified INCR
bytes. If INCR < 0 or INCR > 1, the ADJBP instruction,
which is not implemented on KA-10 or KI-10 processors, is
used. Example: If t:-Copy("ABCDEFGH"),
LOADBYTE(ABSADR(t),5) = Rank('F').
LOADBYTE(8R222215 000001,0) gives the address of the
prototype of the current "main" block, i.e. the prefixed
block, class object, procedure instance or unreduced block
which is innermost in the operating chain. The byte pointer
is POINT 18,1(15),18.
**** WARNING: To be used with caution. Highly machine- and
implementation dependent. See STOREBYTE, STOREWORD.
**** INTEGER PROCEDURE loadword(adr);
INTEGER adr;
Returns the 36-bit word at address ADR, if valid, otherwise
gives "Illegal memory reference" (possibly "Object NONE").
**** WARNING: To be used with caution. Highly machine- and
implementation dependent. See STOREWORD.
**** INTEGER PROCEDURE match6(id1,id2,mask);
INTEGER id1,id2,mask;
ID1 (without wild card characters '?' or '*') is tested
against ID2 with MASK showing wild card positions in ID2 if
any. The result is 1 for an exact match, -1 for a wildcard
match, 0 for no match. ID1 and ID2 are in SIXBIT code. The
wildcard character '?' matches any character. '*' is
equivalent to 6 or less '?' characters: "*" => "??????",
"AB*" => "AB????". The wildcard MASK has octal 77 for each
DECsystem-10 SIMULA Language Handbook, part III Page 118
7. UTILITIES SPECIFIC TO DECSYSTEM-10
'?' in ID2, zeros in the other positions. See WILDSIX.
**** BOOLEAN PROCEDURE numbered
The BOOLEAN PROCEDURE numbered should always be called
immediately after inimage. It will return TRUE if the last
input line was numbered. The internal flag will be reset by
numbered and may be changed by each inimage, even on other
files. For output of line-numbered files, see the
information in the DECsystem-10 SIMULA Language Handbook
part II about the file creation switch /NUMBERED.
**** TEXT PROCEDURE octal(t,n);
TEXT t; INTEGER n;
Returns an octal representation (digits 0-7) of the bit
pattern in N. T is used as workspace. If T.Length < 12,
only the low-order part of N is converted (truncated to the
left). OCTAL.Length = Min(12,T.Length). OCTAL.Main ==
T.Main. OCTAL.Pos points to the first non-zero digit.
Example: t:-Blanks(10); OCTAL(t,-345)="7777777247";
OCTAL(345)="0000000531", Pos=8, thus REST(OCTAL(...))="531".
CONTROLLING SUBJOBS (PTY HANDLING)
Sometimes it is useful to be able to control a subjob from a
SIMULA program. The subjob can do some tasks in parallel
with the controlling job or perform some services which
could not be handled by the controlling job without
interrupting it, perhaps with loss of data and time. A
subjob is controlled by means of a PTY (pseudo-teletype),
which is implemented by monitor software to act as
controlling terminal for the subjob. A PTY is handled like
a terminal using buffered i/o. The following procedures are
coded to aid handling of PTY's in a SIMULA program:
- PTYFIL defines an Outfile object to be used for sending
commands to the subjob. The output from the subjob goes to
the Infile object which is a parameter to PTYFIL.
- PTYINIMAGE is used to get the output from the subjob. The
ordinary Inimage procedure for Infiles cannot be used
because it would loop when there is no input available, or
when the job output does not end with a break character.
- PTYCHECK can be used to wait until the subjob becomes
interactive, i.e. has output available or can accept input.
- JOBSTATUS can be used to check the status of the subjob
without waiting.
- INPUTWAIT can be used to wait for activity on PTY's as
well as TTY's.
DECsystem-10 SIMULA Language Handbook, part III Page 119
7. UTILITIES SPECIFIC TO DECSYSTEM-10
- Actions to control a subjob:
1) Creation of a NEW Infile("PTY:xxx") (specific PTY if
desired).
2) ptyout:-PTYFIL(ptyin), where ptyin is the Infile above.
3) ptyin.Open(Blanks(Sysin.Length)) for example.
ptyout.Open(Blanks(Sysout.Length)).
4) Ordinary Outfile operations (Outchar, Outtext, Outimage,
Breakoutimage) are used for sending commands to the subjob.
Note that no password is required if you LOGIN on the same
ppn as the main job. Check if the job can accept commands
(JOBSTATUS, PTYCHECK, INPUTWAIT) before sending any.
5) Check for job output by PTYCHECK, JOBSTATUS, INPUTWAIT
and use PTYINIMAGE to read the output.
6) Before closing the two PTY files, log out the job,
otherwise it will become detached when the channel is
RELEASEd. The ordinary SIMULA Close procedure has been
modified to work with PTY.
****WARNING**** PTY handling has not been extensively
checked. Proper operation is not guaranteed! See Monitor
Calls for details of PTY handling. Additional functions may
be implemented by the XCALLI procedure, see below.
**** INTEGER PROCEDURE ptycheck(ptyin,timelimit);
REF(Infile)ptyin; REAL timelimit;
Returns job status (according to JOBSTS UUO) if PTY can
accept input or has output within the time limit, otherwise
zero.
Interpretation of returned value:
JB.UJA 8R400000 000000 (negative) Job number is assigned.
JB.ULI 8R200000 000000 Job is logged in.
JB.UML 8R100000 000000 TTY is at monitor level.
JB.UOA 8R040000 000000 TTY output is available.
JB.UDI 8R020000 000000 TTY at user level in input wait,
or at monitor level and can
accept a command.
JB.UJC 8R010000 000000 JACCT is set. In particular,
^C^C will not work.
JB.UJN 8R000000 777777 Job number or zero.
If 0<timelimit<0.001, ptycheck does not wait. If timelimit
<=0, it waits
indefinitely.
DECsystem-10 SIMULA Language Handbook, part III Page 120
7. UTILITIES SPECIFIC TO DECSYSTEM-10
**** REF(Outfile) PROCEDURE ptyfil(ptyinf);
REF(Infile)ptyinf;
Provided PTYINF is an Infile on device PTY, an Outfile will
be opened on the same channel (the same PTY). The result of
PTYFIL is a reference to that Outfile object.
**** INTEGER PROCEDURE ptyinimage(ptyin);
REF(Infile) ptyin;
Performs Inimage for a PTY Infile. Does not need a break
character to stop input. The result is the break character
combination: 7 (^G, BELL), 10 (LF), 11 (VT), 12 (FF), 13
(CR without following LF), 26 (Z), 27 (ESC). CRLF is two
characters = 128*13+10=1674. Special codes:
0 - No break character (null found),
-1 for an empty buffer (no input available),
-2 for no more space in Image, without having found break
character
-3 for other error (to be elaborated?).
The file must be open and be associated with a pseudo-tty.
NOTE! Image must be an initial subtext of Image.Main, i.e.
Image.Main.Sub(1,Image.Length) == Image.
PTYINIMAGE sets Image=Image.Strip, except if
Image.Strip==NOTEXT.
In that case Image = " " and Image.Pos=2.
**** INTEGER PROCEDURE rename(fs1,fs2,force);
NAME fs1,fs2,force; BOOLEAN force; TEXT or REF(FILE) fs1;
TEXT fs2;
FS1 is either a file specification text or a reference to a
file object. FS2 is a (partial) file specification.
Missing fields are taken from FS1. Information from FS2 is
substituted in FS1 and a RENAME UUO is executed. If
FS2==NOTEXT, the file defined by FS1 is deleted. If
FORCE==TRUE, a RENAME changing only the protection is tried
first, then a full RENAME. The result is -1 if RENAME
worked, error code if not. Common error codes:
ERFNF% 0 File not found (refers to first file)
ERIPP% 1 Illegal path (ppn or full sfd path)
ERPRT% 2 Protection failure
ERAEF% 4 Already existing filename
Special error codes:
notdsk 1000 FS1 device is not disk
reoper 1001 Could not reopen FS1
fs2err 1002 Error in FS2
DECsystem-10 SIMULA Language Handbook, part III Page 121
7. UTILITIES SPECIFIC TO DECSYSTEM-10
deverr 1003 Cannot change device (FS2 dev not same as
FS1)
Other error codes are listed in the DECsystem-10 Monitor
Calls manual.
**** INTEGER PROCEDURE rdx50(id,code);
TEXT id; INTEGER code;
COMMENT
Converts id to "RADIX50" code. At most 6 characters
allowed. Only letters (treated as upper case), digits and "
.$%" allowed. CODE must be 0 or > 3 and <= 8R74.
EXTERNAL procedures required:
INTEGER PROCEDURE absadr, storebyte;
INTEGER PROCEDURE bitfield; ;
TEXT t; INTEGER i,j; CHARACTER c;
t:- IF id.Length > 6 THEN id.Sub(1,6) ELSE id;
WHILE t.More DO
BEGIN
c:= t.Getchar; i:= i * 8R50;
IF Letter(c) THEN
BEGIN i:= i + Rank(c) - 8R66;
IF c >= 'a' THEN i:= i - 8R40;
END ELSE
IF Digit (c) THEN i:= i + Rank(c) - 8R57 ELSE
IF c = '.' THEN i:= i + 8R45 ELSE
IF c = '$' THEN i:= i + 8R46 ELSE
IF c = '%' THEN i:= i + 8R47 ELSE
IF NOT c = ' ' THEN GOTO out;
END;
FOR j:= t.Length - 5 STEP 1 UNTIL 0 DO i:= i * 8R50;
IF NOT code = 0 THEN
BEGIN
code:= bitfield(code,30,4);
storebyte(code,8R400400000000 + absadr(i),0);
END;
rdx50:= i;
out:
END rdx50;
DECsystem-10 SIMULA Language Handbook, part III Page 122
7. UTILITIES SPECIFIC TO DECSYSTEM-10
**** INTEGER PROCEDURE reaint(x); REAL x;
Provides type conversion INTEGER to REAL. The integer x is
interpreted as an real quantity with the same bit pattern.
Use with care - highly machine dependent!
**** BOOLEAN PROCEDURE rescan;
A SIMULA program is normally started by some monitor
command. RESCAN backs up the TTY input buffer, if possible,
so that the invoking command can be reread. If the command
line can be reread, RESCAN returns TRUE, else FALSE. The
next input (of a line or a character) from the controlling
TTY (normally SYSIN) will return the command line which
started the SIMULA program, e g:
RUN prog-<parameters>
The monitor command scanner allows command lines which
contain extra information not expected by the monitor
itself. The extra information should be preceded by a
character which is not in the command syntax, like '-', '('.
RESCAN must be called BEFORE the first input from the
terminal. If RESCAN is to be used, file specifications
cannot be taken from the terminal. Any error dialogue
before RESCAN is called will render it useless. Also, you
cannot expect RESCAN to work if you start the program
directly after loading by an EXECUTE or DEBUG command. If
you do not have the program in executable form, you should
use LOAD, then START <some info>. Programs using RESCAN
should always provide an alternative way of getting the
information.
Example (from SIMED):
EXTERNAL BOOLEAN PROCEDURE rescan;
EXTERNAL TEXT PROCEDURE scanto,rest,inline;
TEXT initcommand,t;
IF rescan THEN
BEGIN Inimage;
t:-Sysin.Image.Strip;
IF t=/=NOTEXT THEN t:-Copy(t);
scanto(t,'-'); ! t.Pos after '-' or at end of command
line;
initcommand:- rest(t);
END scanning command line;
...
TEXT command;
command:- IF initcommand =/= NOTEXT THEN initcommand
ELSE inline("*",Sysin);
...
The command R SIMED-X.SIM[100,101]
will yield initcommand = "X.SIM[100,101]", and
just R SIMED will yield initcommand == NOTEXT, causing a
DECsystem-10 SIMULA Language Handbook, part III Page 123
7. UTILITIES SPECIFIC TO DECSYSTEM-10
prompting "*" to be output to show that a command is
expected.
**** SIMATR PROGRAM
Displays ATR file information. This improved version is
written in SIMULA. It displays the SIMULA skeleton of the
separately compiled module together with unique entry names
(also for other required external modules). The external
classes DIRHND and ATRSTR are required to load SIMATR, a
well as a number of external (LIBSIM) procedures.
**** INTEGER PROCEDURE sixbit(t);
TEXT t;
Converts at most 6 characters from the ASCII text T to
SIXBIT, i.e. the code used in the TOPS-10 monitor for names
of devices, files, commands. Each character in SIXBIT is 6
bits, thus only 64 different characters can be represented,
half as many as in ASCII. Lowercase letters are treated as
upper case, and control characters (Char(0) - Char(31))
cannot be represented. SIXBIT translates the first 6
characters of T to sixbit code by subtracting 32 from each
character value < 96 and 64 from the others. Negative
values are made zero (space in sixbit code). The result is
an integer, left justified, which could be used as a sixbit
quantity e.g. with some XCALLI functions. The inverse
function is IDSIXBIT, q.v. See also OCTAL for a way of
representing bit patterns as text strings.
**** INTEGER PROCEDURE sxrx50(w); INTEGER w;
Converts bits 4-35 of W to a RADIX50 identifier expressed in
SIXBIT code (Length=6). Example: Octal 123456701234 is
converted to SIXBIT "OQ5H%3". Bits 0-3 are ignored.
****INTEGER PROCEDURE storebyte(b,bp,incr);
INTEGER b,bp,incr;
Using the byte pointer BP (careful if index and indirection
fields are not zero) store the byte B (last bits according
to byte size) by a DPB or IDPB instruction. If INCR=0 use
DPB, if =1 use IDPB, otherwise modify by ADJBP (only
possible on KL-10/20 systems). See LOADBYTE.
DECsystem-10 SIMULA Language Handbook, part III Page 124
7. UTILITIES SPECIFIC TO DECSYSTEM-10
****INTEGER PROCEDURE storeword(w,adr);
INTEGER w,adr;
Stores the 36-bit word W at address (ADR) in core. For
convenience, the result of the function is the stored value.
Note that indirect addressing is used, which means that the
effective address is modified by any index register
specified in bits 14-17 and indirection will be used if bit
13 is 1. This is dangerous since you cannot control the
contents of ac's in general. Use this procedure ONLY if you
know EXACTLY what you are doing! LOADWORD is the complement
of STOREWORD.
**** TEXT PROCEDURE tmpin(nam,delete);
VALUE nam; TEXT nam; BOOLEAN delete;
Uses the TMPCOR UUO to read the core file NAM into a new
text object. If a core file is not found, a file with name
"TMPNAM(NAM)" (see below) is tried instead (read in dump
mode if found).
If DELETE is TRUE, the file is deleted after reading.
Returns NOTEXT if the file was not found, Blanks(1) if found
but empty.
In the latter case Pos=2 also, otherwise 1. Information to
be read by TMPIN may be created using TMPOUT (see below).
**** TEXT PROCEDURE tmpnam(nam);
VALUE nam; TEXT nam;
TMPNAM takes one parameter NAM. The parameter may be a text
constant, variable or expression whose first three
characters (or fewer than 3 if NAM.Length is less) are used
when forming a temporary file name which is the value of
TMPNAM. The name has the form "jjjnam.TMP", where jjj is
the current job number in decimal notation, and nam are the
first three or fewer characters of the parameter.
File names of this form are used for command files to
standard CUSP's, such as SIMULA, PIP, LINK-10 and should
also be useful for internal scratch files in a SIMULA
program. See the RUN procedure for examples.
DECsystem-10 SIMULA Language Handbook, part III Page 125
7. UTILITIES SPECIFIC TO DECSYSTEM-10
**** BOOLEAN PROCEDURE tmpout(nam,txt);
NAME nam; TEXT nam,txt;
Uses the TMPCOR UUO to write the core file NAM from TXT. If
TMPCOR fails, a real file named "TMPNAM(NAM)" (see TMPNAM
procedure) is opened instead, and TXT is written in dump
mode.
Returns FALSE if the file could not be written, TRUE on
success. No carriage return-line feed will be supplied -
must be in TXT if needed. The text should start and end on
a word boundary.
**** INTEGER PROCEDURE trmop(funcod, iox, val);
INTEGER funcod, val; REF (Outfile) iox;
TRMOP allows the SIMULA program to test and change the
values of certain status items associated with a terminal
connected to the SIMULA program via a file object. The
program can thus achieve the equivalents of the monitor
commands .TTY NO ECHO, .TTY LC etc.
FUNCOD is the four-digit octal code for the function to be
performed.
A first digit = 0 signifies a special function (usually a
generalization of the TTCALL UUO for the job-controlling
terminal).
If the first digit is 1, a read function is performed, i. e.
the current value of the field is returned as function
value.
If the first digit is 2, the corresponding value is set to
the value given by VAL, and the old value is returned as
function value.
The effect of other values of the first digit is
installation dependent.
If the requested function cannot be performed, the value of
the TRMOP function is -1.
IOX is an outfile referring to the TTY involved. IOX==NONE
refers to the terminal controlling the job.
VAL is the new value for the status item. Redundant except
for set function (FUNCOD=8R2xxx).
TRMOP returns the old value of the status item when
relevant.
DECsystem-10 SIMULA Language Handbook, part III Page 126
7. UTILITIES SPECIFIC TO DECSYSTEM-10
Special case: for FUNCOD = 1 or 2, a skip return is mapped
as the function value 1, non-skip return as 0.
Example I: "TRMOP(8R1003,sysout,0)" returns 1 if the
previous setting was "TTY NO LC", returns 0 if the previous
setting was "TTY LC". (TTY NO LC means that the monitor
converts all lower case letters to upper case in
transmissions from the conversational terminal.)
Example II: "TRMOP(8R2003,sysout,1)" is equivalent to the
monitor command "TTY NO LC".
All the status items which can be interrogated or set by
TRMOP are listed in the DECsystem-10 Software Notebooks,
"DECsystem-10 monitor calls", (DEC-10-OMCMA-B-D), Section
11.2.4. Here is an excerpt of the most useful items:
FUNCOD value
8R1003 1 = NO LC (lower case)
8R1005 0 = NO TAB (tabs converted to multiple spaces)
8R1006 0 = NO FORM
8R1007 1 = NO ECHO (printable characters not echoed)
8R1010 1 = NO CRLF (monitor inserts no extra CR-LFs)
8R1011 Horizontal position of carriage
8R1012 Carriage width (TTY WIDTH) = Create <CR><LF> at
given
position in line
8R1013 1 = NO GAG (accepts external messages)
8R1017 TTY FILL (filler class index, governs number of fill
chars after FF and CR)
8R1024 Number of lines output on this page
8R1026 0 = ASCII codes 175 and 176 converted to altmode
8R1035 Create <CR><LF> at first space after given position
in line
DECsystem-10 SIMULA Language Handbook, part III Page 127
7. UTILITIES SPECIFIC TO DECSYSTEM-10
**** INTEGER PROCEDURE ttyline(ttyn); TEXT ttyn;
! Required external procedures: ;
EXTERNAL INTEGER PROCEDURE xcalli, sixbit;
EXTERNAL TEXT PROCEDURE scanto, idsixbit;
BEGIN
! Accepts tty name or number (octal format).
! Returns node*218+line if network is in effect,
! just line no if not, or zero on error.
;
CHARACTER c;
TEXT t;
INTEGER sixname, n;
t:- ttyn;
IF t =/= NOTEXT THEN
BEGIN c:= t.Getchar;
IF Letter(c) THEN
BEGIN
sixname:= sixbit(t);
sixname:= xcalli(8R64,sixname,TRUE,0); ! DEVNAM;
t:- idsixbit(sixname,0);
IF t.Sub(1,3) NE "TTY" THEN GOTO error;
ttyn:- t.Strip;
END letter ELSE
IF Digit(c) THEN
BEGIN ttyn:- Copy("TTY "); ttyn.Setpos(4);
GOTO pc;
WHILE t.More AND ttyn.More DO
BEGIN
c:= t.Getchar;
pc: ttyn.Putchar(c);
END;
END digit;
ttyn.Setpos(1);
ttyline:= xcalli(8R165,sixbit(ttyn),TRUE,0); ! GTNTN.;
END;
error:
;
END;
DECsystem-10 SIMULA Language Handbook, part III Page 128
7. UTILITIES SPECIFIC TO DECSYSTEM-10
**** TEXT PROCEDURE ttynumber(node,lineno);
! Required external procedures: ;
EXTERNAL INTEGER PROCEDURE xcalli;
EXTERNAL TEXT PROCEDURE idsixbit;
INTEGER node, lineno;
BEGIN
! Returns TTY number as octal ASCII text.
! Also returns full TTY device name as ttynumber.Main
! Example: TTY75: ttynumber = "75".
! ttynumber.Main = "TTY75:". Thus ttynumber.Main can be
used directly
! as file specification for the TTY.
;
INTEGER sixname;
sixname:= xcalli(8R166,node*8R1000000+lineno,TRUE,0); !
GTXTN.;
IF sixname NE 0 THEN
BEGIN TEXT t; t:- idsixbit(sixname,0);
t:- t.Main.Sub(1,t.Length+1);
t.Setpos(t.Length); t.Putchar(':');
ttynumber:- t.Sub(4,t.Length-4);
END;
END;
FILED - FOR INPUTTING AND OUTPUTTING DEC-10/20 TEXT FILES:
By Jacob Palme, Swedish National Defense Research Institute,
S-104 50 Stockholm 80, Sweden.
This program contains a class FILED (which can be separately
compiled) to input and output DEC-10/20 ASCII-7-formatted
text files in SIMULA. The program can handle both
unnumbered and line numbered text files. For numbered
files, the program will ensure that the output file has the
line number format required by other DEC-10/20 text handling
programs like SOS. Lines without line numbers will be
numbered.
The good facilities for text handling make SIMULA a useful
language for text handling programs like editors,
programming language translators, compilers, pre-compilers
etc.
However, reading and writing text files on the DEC-10,
especially line numbered files, is rather tricky in SIMULA.
By using this program, you avoid those problems.
The program can be found in a file with the name FILED.SIM
on the SIMULA distribution tape. At the QZ computing
center, you may find the file FILED.SIM on DSKE:[13,134].
DECsystem-10 SIMULA Language Handbook, part III Page 129
7. UTILITIES SPECIFIC TO DECSYSTEM-10
**** INTEGER PROCEDURE xcalli(n,arg,errnoskip,errvalue);
INTEGER n,arg,errvalue; BOOLEAN errnoskip;
Executes CALLI AC1,N - where AC1 is loaded from ARG.
ERRVALUE is returned if the CALLI does not skip, and
ERRNOSKIP is TRUE. See the Monitor Calls manual for CALLI
UUO functions. In TOPS-10, most of the monitor interface is
handled by CALLI. Examples: XCALLI(8R30,0,FALSE,0)=job
number, XCALLI(8R24,0,FALSE,0)=ppn (proj*2^18+prog),
XCALLI(8R31,10,FALSE,0) will cause job to SLEEP 10 seconds,
XCALLI(8R41,m*2^18+n,TRUE,0) will perform GETTAB(m,n) and
return value of item or zero on failure.
For more esoteric functions, you may have to provide an
argument list pointed to by ABSADR(first word of list).
Example:
INTEGER rundev,runfile,runext,run3,runppn,runarg;
rundev:=SIXBIT("SYS"); runfil:=SIXBIT("SIMULA");
XCALLI(8R35,ABSADR(rundev),TRUE,0); EXIT(0);
Will start SIMULA in command mode or exit to monitor on
failure.
XCALLI should be used with great caution. It is provided as
a convenience where safer methods of achieving the desired
results are too cumbersome or impossible. By using XCALLI,
you may not need to write a MACRO-10 procedure for a very
small task, and experimenting is easier. Be very careful
not to cause any garbage collection between computation of
an absolute address and its use!
**** INTEGER PROCEDURE wildsix(id,mask,k);
NAME mask; INTEGER mask, k; TEXT id;
Convert at most K (K <= 6) characters from ID to SIXBIT,
taking special notice of "wild cards" as follows: If a '?'
is found, the corresponding position in MASK (byte size 6)
will be made = 8R77. If an asterisk ('*') is found, the
rest of the characters up to number K (1<=K<=6) will be
treated as '?'. The result is the SIXBIT code of ID
(initial K characters). See PROCEDURE SIXBIT.
Example: ID="AB??", K=6 will give wildsix=8R414237370000,
MASK=8R000077770000.
DECsystem-10 SIMULA Language Handbook, part III Page 130
APPENDIX A - REALTIME - A SCHEDULER FOR TERMINAL PROCESSES
APPENDIX A - REALTIME - A SCHEDULER FOR TERMINAL PROCESSES
(The programs described in this appendix do not work on a
DECsystem-20 at the time when this is written, April 1977.)
CONTENTS
A.1 REALTIME - A SCHEDULER FOR TERMINAL
PROCESSES
A.2 PROCEDURES WAITFORINPUT, INPUTCHECK AND
HOLD(0).
A.3 PROCEDURES CLOCKTIME, SYNCHRONIZE AND
DESYNCHRONIZE.
A.4 STRUCTURE OF THE CLASS REALTIME
A.5 APPLICATION EXAMPLES.
A.5.1.1 SIMULTANEOUS, UNINTERFERED DIALOGUE
BETWEEN THE COMPUTER AND SEVERAL REAL
TERMINALS
A.5.1.2 A COMPLETE PROGRAM USING THE CLASS
REALTIME.
A.5.2 DATA BASE SYSTEM, SEVERAL TERMINALS
A.5.3 LIMITED RESPONSE TIME FOR THE
TERMINAL OPERATOR.
A.5.4 A CONVERSATIONAL TIME-SHARING SYSTEM.
A.5.5 COORDINATED CONTROL OF SIMULTANEOUS
REAL PROCESSES.
A.5.6 SIMULTANEOUS DIALOGUE AND EXECUTION.
DECsystem-10 SIMULA Language Handbook, part III Page 131
APPENDIX A - REALTIME - A SCHEDULER FOR TERMINAL PROCESSES
This documentation is based on FOA P Report C 8394 (June
1974): "Making SIMULA into a Programming Language for Real
Time" by Jacob Palme. (Published in Management Informatics,
Vol. 4, No. 4, August 1975, pp. 129-138.)
The simplest kind of real time application is the execution
of a conversational program running under a time-sharing
system with one external user talking to the program through
a terminal such as a display unit or a typewriter terminal.
This simple interaction can already be easily programmed in
SIMULA. The time-sharing operating system will handle all
the real time problems for the SIMULA program.
But as soon as we want more than one real process to
communicate simultaneously with the SIMULA program, more
advanced real time capabilities are required.
Examples:
- We may want to write a simulation program which
communicates with real components, e.g. human participants.
- We want to let several users from separate terminals
simultaneously access a data base, both fetching and storing
information in it. One master program has to coordinate the
data base accesses so that two users do not simultaneously
try to update the same record. We might want to write this
program in SIMULA.
DECsystem-10 SIMULA Language Handbook, part III Page 132
APPENDIX A - REALTIME - A SCHEDULER FOR TERMINAL PROCESSES
A.1.3 Procedures WAITFORINPUT, INPUTCHECK and HOLD(0).
The execution of a SIMULA process is only interrupted where
explicit statements like "HOLD" or "PASSIVATE" cause control
to transfer from the process to the scheduler. A common
error when programming real time programs is that one
parallel process uses partly updated data, produced by
another parallel process. For small in-core updates, a
programmer in SIMULA can avoid this error by only putting
statements like "HOLD" and "PASSIVATE" at places in the
source program where data updates are complete.
For more complex updates, a special process can be written
to access the critical data, and other processes requesting
updates can be queued to the special process. When a SIMULA
process executes a statement like "HOLD" or "PASSIVATE",
then control goes to the SIMULA scheduler, which then
transfers control to another process.
"HOLD(A)" stops execution of the current process but asks
the SIMULA scheduler to restart it after A time units. If A
is zero, then the current process is stopped and placed at
the end of a queue of currently active processes. If a
number of processes successively make "HOLD(0.0)" they will
thus get access to the CPU in a round robin fashion.
A SIMULA programmer can thus ensure fast response to
external interrupts by not doing too much computations
between successive "HOLDS".
"PASSIVATE" stops the current process indefinitely, it must
be activated again from some other process.
Processes waiting for external interrupts are put into a
special queue with the procedure call "WAITFORINPUT". The
"SIMULATION CLASS REALTIME" contains a special version of
"HOLD" and an alternative version of "PASSIVATE" called
"TERMINAL_PASSIVATE" and these procedures first scan this
special queue to see if data has arrived from the input
device associated with the terminal processes.
If a process is found for which data has arrived on the
associated input device, then the SIMULA scheduler activates
this process immediately.
The event created by the first external interrupt found is
thus placed in front of other currently active processes in
the sequencing set. This, however, is not done at the time
of the interrupt, the placing is done at the time of the
next activation of the scheduler after the interrupt.
DECsystem-10 SIMULA Language Handbook, part III Page 133
APPENDIX A - REALTIME - A SCHEDULER FOR TERMINAL PROCESSES
Inside a terminalprocess, a call "WAITFORINPUT" will thus
tell the system to make this process passive, but to
reactivate it as soon as new data has arrived on the input
device associated with the process.
A new BOOLEAN standard procedure INPUTCHECK is also
introduced. INPUTCHECK is TRUE if and only if data is
available (i.e. has arrived from the terminal device) for
reading with INIMAGE.
A.3 Procedures CLOCKTIME, SYNCHRONIZE and DESYNCHRONIZE.
For real time applications, we may also want to synchronize
simulated time with real time. For this there are three new
standard procedures:
REAL PROCEDURE clocktime; COMMENT gives time in seconds
since the beginning of the current day;
PROCEDURE synchronize(timeunit); REAL timeunit; COMMENT
this procedure starts synchronization of real and simulated
time;
PROCEDURE desynchronize; COMMENT and this stops
synchronization;
Of course perfect synchronization of real and simulated time
is not possible since the speed of the computer itself is
not infinite. The package tries to synchronize, and never
allows simulated time to become more than a fraction of a
second greater than real time.
Synchronization consumes some additional cpu time.
If the scheduler finds that the next process to be scheduled
has a too large simulated time, then the SIMULA scheduler
lets the SIMULA program go to sleep for the necessary time
interval. Any interrupts caused by input will however start
the SIMULA program again.
The parameter "timeunit" to the procedure "synchronize" is
there since the time unit may not be the same in the
simulation as in the real world. "timeunit" is the size of
the simulation time unit in seconds. Thus, if simulated
time is measured in seconds, "timeunit" should be 1.0. If
simulated time is measured in hours, "timeunit" should be
60*60.
DECsystem-10 SIMULA Language Handbook, part III Page 134
APPENDIX A - REALTIME - A SCHEDULER FOR TERMINAL PROCESSES
A.4 Structure of the class REALTIME
OPTIONS(/E);
EXTERNAL BOOLEAN PROCEDURE inputcheck;
EXTERNAL PROCEDURE sleep, abort;
EXTERNAL INTEGER PROCEDURE inputwait;
EXTERNAL REAL PROCEDURE clocktime;
simulation CLASS realtime;
NOT HIDDEN PROTECTED synchronize, desynchronize,
terminal_passivate,
hold, terminalprocess;
NOT HIDDEN process, current, time, passivate, wait,
main, linkage, link, head;
BEGIN
PROCEDURE synchronize(timeunit); REAL timeunit;
COMMENT this procedure starts synchronization of real and
simulated time;
BEGIN ... END;
PROCEDURE desynchronize;
COMMENT This procedure ends synchronization of real and
simulated time;
BEGIN ... END;
PROCEDURE terminal_passivate;
COMMENT special version of passivate for a
terminalprocess;
BEGIN ... END;
PROCEDURE wait(q); REF (head) q;
COMMENT special version of wait for a terminalprocess;
BEGIN ... END;
PROCEDURE hold(delaytime); REAL delaytime;
COMMENT special version of hold for terminalprocesses.
hold(0.0) gives round robin process scheduling;
BEGIN ... END;
process CLASS terminalprocess(fromterminal);
REF (infile) fromterminal;
NOT HIDDEN PROTECTED fromterminal, waitforinput;
NOT HIDDEN evtime, nextev, into;
BEGIN
PROCEDURE waitforinput;
COMMENT this process waits until inimage is
possible to make for some file in the input_array;
BEGIN ... END;
END of terminalprocess;
DECsystem-10 SIMULA Language Handbook, part III Page 135
APPENDIX A - REALTIME - A SCHEDULER FOR TERMINAL PROCESSES
END of class realtime;
A.5 Application examples.
In this section you can see how the new concepts can be
used. Some examples will be given of real time programs
written in SIMULA using the new concepts.
The programs are not always complete. Three dots indicate
places where something has been left out.
A.5.1.1 Simultaneous, uninterfered dialogue between
the computer and several real terminals.
One master terminal reads file specifications for the other
terminals and starts up one copy of the SIMULA CLASS
"terminal" for each of the other terminals. Each of these
"terminalprocesses" will open the connection to its real
terminal, and then go into a loop of (a) waiting for input
and (b) producing answers.
Each of these terminal loops will go on independently of the
other, and the SIMULA scheduler will distribute control
between the "terminalprocesses".
terminalprocess CLASS terminal(toterminal);
REF (outfile) toterminal;
BEGIN
INSPECT fromterminal DO
INSPECT toterminal DO
BEGIN
PROCEDURE open_terminal_connections; ...
PROCEDURE read_the_input_and_produce_an_answer; ...
WHILE TRUE DO
BEGIN
waitforinput;
read_the_input_and_produce_an_answer;
END;
END;
END;
DECsystem-10 SIMULA Language Handbook, part III Page 136
APPENDIX A - REALTIME - A SCHEDULER FOR TERMINAL PROCESSES
ACTIVATE NEW terminal(sysin,sysout);
ACTIVATE NEW terminal(NEW infile("TTY2:"),
NEW outfile("TTY2:"));
ACTIVATE NEW terminal.....
....
passivate;
A.5.1.2 A complete program using the CLASS REALTIME.
Here follows a complete, small program using the CLASS
REALTIME.
At each terminal, the program returns the input
received at that terminal. If the input at a terminal
is a legal TTY device specification, that terminal
is connected to the program.
BEGIN
EXTERNAL BOOLEAN PROCEDURE inputcheck;
EXTERNAL PROCEDURE sleep, abort;
EXTERNAL INTEGER PROCEDURE inputwait;
EXTERNAL REAL PROCEDURE clocktime;
EXTERNAL CLASS realtime;
EXTERNAL REF (infile) PROCEDURE findinfile;
EXTERNAL REF (outfile) PROCEDURE findoutfile;
DECsystem-10 SIMULA Language Handbook, part III Page 137
APPENDIX A - REALTIME - A SCHEDULER FOR TERMINAL PROCESSES
realtime BEGIN
terminalprocess CLASS terminal(toterminal);
REF (outfile) toterminal;
BEGIN
TEXT stripimage;
INSPECT fromterminal DO INSPECT toterminal DO
WHILE fromterminal.image.sub(1,2) NE "/*" DO
BEGIN
waitforinput; inimage;
stripimage:- fromterminal.image.strip;
IF stripimage =/= NOTEXT THEN
BEGIN
IF stripimage.sub(stripimage.length,1)
= ":" THEN
BEGIN COMMENT Connect another terminal;
IF connect(stripimage) THEN
outtext("NEW LINE OPEN. ") ELSE
outtext("NOT ABLE TO OPEN THAT LINE. ");
END;
END;
outtext("I received: '");
outtext(stripimage); outtext("'");
outimage;
END;
toterminal.close; fromterminal.close;
END;
BOOLEAN PROCEDURE connect(filespec);
VALUE filespec; TEXT filespec;
INSPECT findinfile(filespec) DO
BEGIN
open(blanks(80));
INSPECT findoutfile(filespec) DO
BEGIN
open(blanks(80));
connect:= TRUE;
outtext(
"THIS TERMINAL IS NOW CONNECTED!");
outimage;
ACTIVATE NEW terminal
(THIS infile, THIS outfile);
END
OTHERWISE close;
END;
DECsystem-10 SIMULA Language Handbook, part III Page 138
APPENDIX A - REALTIME - A SCHEDULER FOR TERMINAL PROCESSES
ACTIVATE NEW terminal(sysin, sysout);
passivate;
END of realtime prefixed block;
END of the whole program;
A.5.2 Data base system, several terminals
use the same data base.
This is a very simple example of a data base system with
several conversational terminals which independently put
requests (questions or updates) to a data base. The actual
data base accesses must be done for only one request at a
time to avoid errors when one terminal tries to read what
another terminal is updating.
The SIMULA program contains one process for each terminal
and one process for the data base.
The terminal processes wait for input from their respective
terminals. When a data base request has been received, the
terminal process is put into a queue of data base requests.
The data base process takes one terminal process at a time
from this queue and processes the data base request.
Thereafter, the data base process ACTIVATEs the terminal
process again. When ACTIVATEd, this terminal process writes
the answer to its terminal and waits for new requests from
it.
DECsystem-10 SIMULA Language Handbook, part III Page 139
APPENDIX A - REALTIME - A SCHEDULER FOR TERMINAL PROCESSES
realtime BEGIN
REF (head) request_queue;
REF (data_base) the_data_base;
terminalprocess CLASS terminal(toterminal);
REF (outfile) toterminal;
BEGIN
INSPECT fromterminal DO
INSPECT toterminal DO
BEGIN
PROCEDURE open_terminal_line; ...
PROCEDURE read_and_prepare_data_base_request; ...
PROCEDURE write_the_answer_to_the_request; ...
WHILE TRUE DO
BEGIN
waitforinput;
read_and_prepare_data_base_request;
ACTIVATE the_data_base DELAY 0;
wait(request_queue);
write_the_answer_to_the_request;
END;
END;
END;
process CLASS data_base;
BEGIN
INSPECT NEW
directfile(data_base_file_specifications) DO
BEGIN
PROCEDURE open_data_base_file; ...
PROCEDURE put_the_request_to_the_data_base; ...
open_data_base_file;
WHILE TRUE DO
INSPECT request_queue.first WHEN terminal DO
BEGIN
out; COMMENT to remove the terminal from the
request queue;
put_the_request_to_the_data_base;
ACTIVATE THIS terminal;
END OTHERWISE passivate;
END;
END;
DECsystem-10 SIMULA Language Handbook, part III Page 140
APPENDIX A - REALTIME - A SCHEDULER FOR TERMINAL PROCESSES
A.5.3 Limited response time for the terminal operator.
This is a very simple example of a program which is
coordinated with the time in the real world. A question is
given to a terminal operator and the program waits for an
answer. The program should take different action depending
on whether the answer is received within 60 seconds or not.
To do this, the new standard procedure SYNCHRONIZE is used
to synchronize real time with the simulated time in SIMULA.
terminalprocess CLASS terminal(toterminal);
REF (outfile) toterminal;
BEGIN
INSPECT fromterminal DO
INSPECT toterminal DO
BEGIN
REAL questiontime;
PROCEDURE write_question_to_the_terminal; ...
PROCEDURE process_fast_answer; ...
PROCEDURE process_slow_answer; ...
synchronize(1.0);
write_question_to_the_terminal;
questiontime:= time;
waitforinput;
IF time - questiontime < 60.0 THEN
process_fast_answer ELSE
process_slow_answer;
END;
END;
A.5.4 A conversational time-sharing system.
The conversational time-sharing system in this example could
be an interpreter for a language like APL or FOCAL or AID.
Highest priority is given to those input commands which are
to be performed directly. Lower priority is given to input
commands requesting the execution of a stored program. When
several stored programs are in execution at the same time,
CPU power is distributed between them in a round robin
fashion letting each program perform one statement in the
stored program before continuing to the next program.
DECsystem-10 SIMULA Language Handbook, part III Page 141
APPENDIX A - REALTIME - A SCHEDULER FOR TERMINAL PROCESSES
terminalprocess CLASS terminal(toterminal);
REF (outfile) toterminal;
BEGIN
INSPECT fromterminal DO
INSPECT toterminal DO
BEGIN
PROCEDURE open_terminal_connections; ...
PROCEDURE read_the_input_and_produce_an_answer;
BEGIN
BOOLEAN more_statements, execute_command;
PROCEDURE read_and_interpret_an_input_line; ...
PROCEDURE
execute_the_next_stored_program_statement; ...
PROCEDURE perform_the_command_from_the_input_line;
...
read_and_interpret_an_input_line;
IF NOT execute_command THEN
perform_the_command_from_the_input_line ELSE
WHILE more_statements DO
BEGIN
HOLD(0); COMMENT to transfer control to another
process;
execute_the_next_stored_program_statement;
END;
END;
WHILE TRUE DO
BEGIN
waitforinput;
read_the_input_and_produce_an_answer;
END;
END;
END;
DECsystem-10 SIMULA Language Handbook, part III Page 142
APPENDIX A - REALTIME - A SCHEDULER FOR TERMINAL PROCESSES
A.5.5 Coordinated control of simultaneous real processes.
When a real time computer program communicates with several
simultaneous processes in the real world, the computer
program may want to control itself or the real-world
processes depending on the results in the various processes.
Example 1: A simulation program may want to continue the
simulation when all the terminals have replied to certain
questions.
Example 2: A process control program may monitor several
real-world processes, and initiate other real-world actions
when previous processes are ready.
This is similar to PERT-networks in planning, where certain
actions must wait for other actions to finish.
To illustrate this, a simple example assumes a robot with
three arms. A process "put nail in board" is initiated.
This process initiates three simultaneous processes, the
first arm gets a hammer, the second arm gets a nail, and the
third arm gets a board. When all these three processes are
finished, the hammer is used to push the nail into the
board.
In other languages, special constructs like "fork" and
"join" are used to create parallel processes and then
continue when all the processes are ready. But the same
thing is very simple to program in SIMULA, and in SIMULA we
do not have to wait until a process is completely finished,
we can also easily start a later process when still running
processes have reached certain states.
DECsystem-10 SIMULA Language Handbook, part III Page 143
APPENDIX A - REALTIME - A SCHEDULER FOR TERMINAL PROCESSES
terminalprocess CLASS arm(toterminal);
REF (outfile) toterminal;
BEGIN
INSPECT fromterminal DO
INSPECT toterminal DO
BEGIN
TEXT order; BOOLEAN ready; REF (process) master;
PROCEDURE perform_order; ...
WHILE TRUE DO
BEGIN
terminal_passivate;
ready:= FALSE; perform_order; ready:= TRUE;
ACTIVATE master DELAY 0;
END;
END;
END;
process CLASS put_nail_in_board(arm1, arm2, arm3);
REF (arm) arm1, arm2, arm3;
BEGIN
arm1.order:- copy("find hammer"); arm1.master:- current;
arm2.order:- copy("find nail"); arm2.master:- current;
arm3.order:- copy("find board"); arm3.master:- current;
ACTIVATE arm1 DELAY 0;
ACTIVATE arm2 DELAY 0;
ACTIVATE arm3 DELAY 0;
terminal_passivate;
WHILE NOT (arm1.ready AND arm2.ready AND arm3.ready)
DO terminal_passivate;
arm1.order:- copy("swing hammer");
ACTIVATE arm1 DELAY 0;
...
END;
A.5.6 Simultaneous dialogue and execution.
On many occasions, you may want a program to execute and
talk to the user at the same time. You may for example want
to allow the user to ask the computer how far the execution
has reached. This is especially useful for time-consuming
executions, where the user may get impatient and may want to
know if the delay is caused by machine error, erroneous data
to the program, by a heavy load on the machine or just by a
time-consuming execution in general.
One can then write a program with two processes, one process
for talking to the user and another process for the
time-consuming execution.
DECsystem-10 SIMULA Language Handbook, part III Page 144
APPENDIX A - REALTIME - A SCHEDULER FOR TERMINAL PROCESSES
terminalprocess CLASS userdialogue(toterminal);
REF (outfile) toterminal;
BEGIN
INSPECT fromterminal DO
INSPECT toterminal DO
BEGIN
ACTIVATE NEW cpuactivity DELAY 0;
WHILE TRUE DO
BEGIN
outline("CPU activity has begun. If you want to");
outline("know what is happening, then type");
outline("""?"" on your terminal");
waitforinput; inimage;
tell_the_user_what_is_happening;
END;
END;
END;
DECsystem-10 SIMULA Language Handbook, part III Page 145
APPENDIX B - CONTROLLED ERROR HANDLING
APPENDIX B - CONTROLLED ERROR HANDLING
By Stefan Arnborg August 1975, Modified October 1975
CONTENTS
B.1 PROBLEM
B.2 SOLUTIONS
B.3 CHOICE OF SOLUTION FOR SIMULA
B.4 PROPOSAL
B.5 DISCUSSION
The procedures MASKERROR, SENSEERROR, JUMPERROR and
RESETERROR described below have not yet been implemented,
and no promise is made about if or when to do so.
B.1 Problem.
Dependable software must be prepared to detect and diagnose
errors in input data. For complex problems error handling
will take a significant part of the programming effort.
Programmed error handling is a means to achieve error
handling without having to reprogram in SIMULA checks
actually made by the programming system and the hardware.
The absence of this facility has been used as one argument
for using PL/1 rather than SIMULA at FOA.
B.2 Solutions.
Programmed error handling in other programming systems and
environments usually falls in one of three classes:
A Implicit action.
In CDC Algol an error may cause a jump to a preset label.
In the Knuth proposal for I/O in Algol 60, errors may cause
predefined procedures to be called. In PL/1 an error may
cause a previously set ON-unit to be activated.
DECsystem-10 SIMULA Language Handbook, part III Page 146
APPENDIX B - CONTROLLED ERROR HANDLING
B Error returns.
The READ/WRITE statements of many FORTRAN implementations
permit error and end-of-file exit labels to be passed as
parameters. Many general-purpose algorithms in ACM
collected algorithms have parameters returning error codes
or error exit label parameters.
C Raising flags.
In the CODASYL DBMS proposal, an error condition raises
flags that can be inspected by the program.
B.3 Choice of solution for SIMULA.
The following requirements on a solution are rather obvious:
i) Existing programs should not be affected unless the
user wants to take advantage of the facility.
ii) It must be easily implemented on existing systems.
iii) It must be well defined and easy to use.
iv) It must be compatible with the overall language
philosophy.
v) In particular, it must be as implementation independent
as possible.
Method A seems to satisfy i) and v) but contradicts the
other requirements. In particular, it requires much
programming effort (at least in the IBM 360 and DEC 10
implementations) to be able to enter a user program point
from anywhere in the run-time system. However, an implicit
jump is easier to implement than an implicit procedure call.
It has the slight drawback that it is difficult to know
where the error occurred and to proceed after corrections,
because bookkeeping operations like e.g. file positioning
may get out of phase. It is also not agreed that implicit
actions are consistent with good programming methodology.
Method B contradicts i) or ii) and iv) depending on whether
the additional parameters are made compulsory or optional.
Moreover, it takes care only of errors in system procedures.
DECsystem-10 SIMULA Language Handbook, part III Page 147
APPENDIX B - CONTROLLED ERROR HANDLING
Method C complies with all requirements to a reasonable
degree. However, it requires a program to continue after an
error has occurred and this continued execution will maybe
not be entirely implementation independent. It can be seen
as a method to achieve an orderly failure rather than a
means to implement a complicated polyalgorithm. It is easy
to implement recovery procedures of differing levels of
detail as in the example:
BEGIN initialize_sequence_of_batches;
WHILE more_batches DO
BEGIN
process_batch:
WHILE more_records DO
BEGIN process_record:
WHILE more_fields DO
BEGIN process_field;
recovery1;
END;
recovery2;
END;
recovery3;
END;
END;
At each of the recovery points it is possible to prevent
upward updates from an erroneous field, record or batch.
B.4 Proposal.
It is suggested that the following text be inserted into the
SDG publications:
"Programmed Error Handling.
The programmed error handling facilities of SIMULA make it
possible to achieve, in a SIMULA program, an orderly
handling of certain errors occurring during execution as a
result of incorrect or unexpected inputs to the program.
Errors are classified into the following categories:
DECsystem-10 SIMULA Language Handbook, part III Page 148
APPENDIX B - CONTROLLED ERROR HANDLING
1 Underflow in floating point computation
2 Overflow in computation or division by zero
3 I/O transmission error
4 End of file error
5 Edit overflow
6 Incorrect text contents for de-editing procedure
7 Array index out of range
8 Incorrect parameter to mathematical function
9 Time limit - as defined by a previous call to TIMELIMIT
- exceeded.
10 All the errors listed above.
999999 Remaining errors that can be intercepted in an
implementation.
The errors above are not all errors that can result from
incorrect data but only those that will occur as a direct
and immediate consequence of invalid data. Second order
errors result from following an incorrect path of the
program because of invalid data: those errors are not
handled.
The following system procedures are available for error
handling:
[Addition by Jacob Palme 1976-03] Possibly we could allow an
implementation to add an implementation dependent number of
extra error codes, between 11 and 999998. The error code
999999 would then be equivalent to all such error codes,
which means that programs using only error codes 1-8 will
still be machine independent and programs using error codes
9, 10 and 999999 will be reasonably machine independent,
while programs using extra error codes between 11 and 999998
will at their own risk be machine dependent.
**** PROCEDURE MASKERROR(CODE,COUNT); INTEGER CODE,COUNT;
Execution of MASKERROR permits COUNT errors of category CODE
to occur without intervention by the run time system. The
effect of continuing after an error is dependent on the kind
of error: (On certain computers, the architecture may make
these default effects impossible. If so, they may do
otherwise.)
1. Result of operation is zero.
2. Result of operation is zero.
DECsystem-10 SIMULA Language Handbook, part III Page 149
APPENDIX B - CONTROLLED ERROR HANDLING
3. The image fetched will contain the record as
transmitted, if possible. Otherwise a blank image will
be fetched.
4. The image will be set to blanks. ENDFILE will still be
TRUE if sensed.
5. The field of the operation will contain asterisks.
6. The result will be zero.
7. The first acceptable index (i e the lower bound) will be
used. Note that on some implementations the first
ELEMENT (lower bound everywhere!) may have to be used.
8. The result of the function will be zero.
9. No action, job continues.
11-999999. Implementation dependent.
A new call to MASKERROR resets the previous error count (as
returned by SENSEERROR).
If an implementation enters dialog or debug mode in case of
an error of a category mentioned above, this facility will
be suppressed by a call to MASKERROR for the category.
When the program starts, categories 1 and 5 are
automatically masked by the SIMULA system with a large value
on COUNT.
**** PROCEDURE JUMPERROR(CODE,L); INTEGER CODE; LABEL L;
Execution of JUMPERROR directs the run time system to make
an implicit jump to L if an error of category CODE occurs.
The sequence of operations is interrupted so that no effect
of the illegal operation remains when L is entered, nor will
it be possible to find out exactly which operation caused
the error, except indirectly from the contents of program
variables.
The label L must be in the outermost block of the main
program (recovery for the otherwise possible ILLEGAL GOTO
may be very difficult or impossible to implement). From
this follows that JUMPERROR cannot be called in a separately
compiled module. A call to jumperror for other labels than
in the outermost block should cause an error interrupt.
Both MASKERROR and JUMPERROR can be called for an error
DECsystem-10 SIMULA Language Handbook, part III Page 150
APPENDIX B - CONTROLLED ERROR HANDLING
category, but the last call has effect.
Dialogue and debug mode recoveries are suppressed by
JUMPERROR as by MASKERROR.
**** PROCEDURE RESETERROR(CODE); INTEGER CODE;
Execution of RESETERROR inhibits the effect of previous
calls to MASKERROR or JUMPERROR for the category CODE.
Subsequent errors are intercepted and diagnosed.
**** INTEGER PROCEDURE SENSEERROR(CODE); INTEGER CODE;
A call to SENSEERROR returns the number of errors of
category CODE that have occurred. If CODE is zero, the
total number of errors is returned. SENSEERROR does not
reset the error counts.
B.5 Discussion.
This proposal was modified at in October 75 after the SDG
meeting. The proposal can be modified in several areas to
accomplish a different balance between implementability and
implementation independence:
The error categories can be made finer or coarser, in
particular the existence of categories 11-999999 is
debatable;
Default settings can be altered;
One may redefine results of undefined operations;
One may specify the error categories by reference to the
sections in the Common Base or Algol report where the error
is described;
It is possible to use different system procedures instead of
having the non-natural assignment of codes to error
categories;
These questions are best solved (if the proposal is
accepted) in the Simula Development Group.
DECsystem-10 SIMULA Language Handbook, part III Page 151
APPENDIX C - INDEX
APPENDIX C - INDEX
------------------
ABORT EXTERNAL PROCEDURE . . . 46
ABSADR EXTERNAL INTEGER PROCEDURE, address of a variable 108
Access protection . . . . . . . 138
Access to memory without checking, LOADBYTE 117
Access to memory without checking, LOADWORD 117
Access to memory without checking, STOREBYTE 123
Access to memory without checking, STOREWORD 124
Address of a variable, absolute 108
ADJPTR EXTERNAL INTEGER PROCEDURE (adjust byte pointer) 108
ADVANCE of magtapes . . . . . . 44
Alphanumerical display terminal 25
ALTMODE TTY bit setting from a SIMULA program 125
ANDINT procedure (bitwise AND between 36-bit words) 108
APPROX EXTERNAL INTEGER PROCEURE 53
Arnborg, Stefan . . . . . . . . 145
Array index range error . . . . 148
ARRLGD EXTERNAL INTEGER PROCEDURE 86
ARRTXT EXTERNAL PROCEDURE . . . 86
ASCII to SIXBIT conversion, SIXBIT procedure 123
ASCII to SIXBIT conversion, WILDSIX procedure 129
ATR file structure, SIMATR program 123
ATRSTR EXTERNAL CLASS, attribute file structure 109
Attribute file structure, ATRSTR class 109
Attribute file structure, display by SIMATR program 123
BACKSPACE of magtapes . . . . . 44
Binary input/output . . . . . . 38
Binary to octal conversion, OCTAL procedure 118
Bit manipulation, ANDINT procedure 108
Bit manipulation, BITGET procedure 109
Bit manipulation, BITPUT procedure 109
Bit manipulation, BOOLFUNC procedure 110
Bit manipulation, DEPBYTE procededure 113
Bit manipulation, INTREA procedure 117
Bit manipulation, LOADBYTE . . 117
Bit manipulation, REAINT procedure 122
Bit manipulation, STOREBYTE . . 123
BITFIELD EXTERNAL INTEGER PROCEDURE 109
BITGET EXTERNAL INTEGER PROCEDURE 109
BITPUT EXTERNAL INTEGER PROCEDURE 109
Blanks, removal of . . . . . . 60
BOKSTAV EXTERNAL BOOLEAN PROCEDURE 107
BOOLEAN data stored as bit strings 109
BOOLFUNC EXTERNAL INTEGER PROCEDURE 110
BREAKOUTLINE EXTERNAL PROCEDURE 87
BYPASS EXTERNAL BOOLEAN PROCEDURE 42
Byte handling, BITFIELD procedure 109
Byte handling, DEPBYTE procedure 113
Byte handling, STOREBYTE . . . 123
Byte manipulation, LOADBYTE procedure 117
Byte pointer manipulation, ADJPTR procedure 108
CALLI UUO executed directly from SIMULA, XCALLI procedure 129
CALLMIC EXTERNAL INTEGER PROCEDURE 110
CAT demo program, cat and mouse game 27
CDCSIM Conversion Program . . . 28
CHANGE EXTERNAL BOOLEAN PROCEDURE 74
Change partial word, DEPBYTE procedure 113
Character byte pointer manipulation 108
Character format transformation from ASCII to SIXBIT 116
Character input, echo control of 114
CHARACTER output, direct . . . 36
CHECKEXTENSION EXTERNAL TEXT PROCEDURE 113
CHECKFRAC EXTERNAL INTEGER PROCEDURE 66
Checking of terminal input data 17
CHECKINT EXTERNAL INTEGER PROCEDURE 64
CHECKREAL EXTERNAL INTEGER PROCEDURE 64
CLOCKTIME EXTERNAL REAL PROCEDURE 32
CLOSEOPEN EXTERNAL PROCEDURE . 45
Codasyl-type Data Base Management 22
Command input to SIMULA programs, RESCAN procedure 122
Command interpreter (DEC-10 style), DECOM 83
Command line scan, SCAN procedure 79
Communication between programs, TMPIN procedure 124
Communication between programs, TMPOUT procedure 125
Communication with monitor, XCALLI (CALLI UUO) 129
COMPRESS EXTERNAL TEXT PROCEDURE 71
CONC EXTERNAL TEXT PROCEDURE . 70
CONC2 EXTERNAL TEXT PROCEDURE . 70
Conditions of release . . . . . 2
CONTROL-C, simulated from program 50
CONTROLLED ERROR HANDLING. . . 46
Conversational I/O . . . . . . 17
Conversational system . . . . . 140
Conversational terminal . . . . 135
Conversion from ASCII to SIXBIT, SIXBIT procedure 123
Conversion from ASCII to SIXBIT, WILDSIX procedure 129
Conversion from binary to octal, OCTAL procedure 118
Conversion from RADIX50 to ASCII, IDRX50 procedure 116
Conversion from SIXBIT to ASCII, IDSIXBIT procedure 116
Conversion programs . . . . . . 28
Copying of disk files, FILCOPY procedure 114
Copyright of the SIMULA system 2
COREGUIDE EXTERNAL BOOLEAN PROCEDURE 53
CORELIMIT EXTERNAL BOOLEAN PROCEDURE 52
COSYS, part of FIGURE . . . . . 7
COSYSF, part of FIGURE . . . . 7
CP(U)TIME EXTERNAL REAL PROCEDURE 32
CRLF TTY bit setting from a SIMULA program 125
CTRL-C, simulated from program 50
CTRL-O bit resetting . . . . . 45
DAHELP EXTERNAL CLASS . . . . . 26
Data base handling . . . . . . 23
Data Base Management . . . . . 22
Data collection, form method . 27
Data entry by form fill in . . 26
Data transmission errors . . . 146
DATE . . . . . . . . . . . . . 31
DAYNO EXTERNAL INTEGER PROCEDURE 31
DAYTIME EXTERNAL TEXT PROCEDURE 32
DBMMIN, part of SIMDBM system . 23
DBMS error condition . . . . . 146
DBMSET, part of SIMDBM system . 23
DDTDEM SIMDDT demo program . . 27
De-editing procedure error . . 148
DEC-style command interpreter, DECOM 83
DECOM EXTERNAL CLASS, see also SCAN 83
Deleting a file, RENAME procedure 120
Deleting files . . . . . . . . 44
Demo programs . . . . . . . . . 27
Demonstration programs . . . . 27
DEPBYTE EXTERNAL PROCEDURE . . 113
DEPCHAR EXTERNAL PROCEDURE . . 60
Desynchronize . . . . . . . . . 133
Dialogue I/O . . . . . . . . . 17
DIMENSIONS EXTERNAL INTEGER PROCEDURE 53
Direct access files, application package with 23
Direct access files, text editing of 23
Direct Access Help files . . . 26
DIRECTFILE binary I/O . . . . . 42
DIRECTFILE HANDLING PROGRAMS . 30
Directfile text editing - DIRED 30
DIRECTFILE to seqeuential file conversion 30
Directory sorting, SORTDN procedure 99
DIRED Direct file editor . . . 23
DIRED program . . . . . . . . . 30
DIRHND EXTERNAL CLASS . . . . . 113
DIRSEQ program . . . . . . . . 30
Disk-to-disk copy, FILCOPY procedure 114
Display terminal . . . . . . . 25
Division by zero error . . . . 148
DOTYPEOUT EXTERNAL BOOLEAN PROCEDURE 45
ECHO EXTERNAL PROCEDURE . . . . 114
ECHO TTY bit setting from a SIMULA program 125
Edit overflow error . . . . . . 148
Editing of SIMULA direct access files 23
ENTERDEBUG EXTERNAL PROCEDURE . 46
Entry of data by form fill in . 26
ENVIRONMENT ENQUIRY . . . . . . 53
Error flags . . . . . . . . . . 146
ERROR INTERRUPT ROUTINES . . . 46
Error recovery . . . . . . . . 147
EXIT EXTERNAL PROCEDURE . . . . 50
EXIT, immediate, from execution 50
Extracting a field from a 36-bit word, BITFIELD procedure 109
FETCH.SIM part of SIMDBM . . . 23
FETCHAR EXTERNAL CHARACTER PROCEDURE 60
FIGURE graphic package . . . . 25
FILCOPY EXTERNAL INTEGER PROCEDURE 114
File conversion, to and from directfile 30
File directory handling, DIRHND class 113
FILE HANDLING . . . . . . . . . 44
File lookup, FLOKUP procedure . 115
File renaming or deletion, RENAME procedure 120
File specification string, FILSPC procedure 115
FILENAME EXTERNAL TEXT PROCEDURE 35
FILL TTY bit setting from a SIMULA program 125
FILSPC EXTERNAL TEXT PROCEDURE 115
FINDDIRECTFILE EXTERNAL REF (DIRECTFILE) PROCEDURE 44
FINDINFILE EXTERNAL REF (INFILE) PROCEDURE 44
FINDOUTFILE EXTERNAL REF (OUTFILE) PROCEDURE 44
FINDPRINTFILE EXTERNAL REF (PRINTFILE) PROCEDURE 44
FINDTRIGGER EXTERNAL CHARACTER PROCEDURE 62
Flags, marking errors . . . . . 146
Floating point error . . . . . 148
FLOKUP EXTERNAL INTEGER PROCEDURE 115
FORCEOUT EXTERNAL PROCEDURE . . 37
Form fill in data entry . . . . 26
FORM form fill in data entry package 26
Form method of data collection 27
FORM package, test programs . . 27
FORM TTY bit setting from a SIMULA program 125
FORSIM EXTERNAL PROCEDURE . . . 46
FORTRAN programming language . 146
FQC Program measurement system 29
FREEBITS EXTERNAL INTEGER PROCEDURE 51
FREEZE EXTERNAL PROCEDURE . . . 49
FROM EXTERNAL TEXT PROCEDURE . 59
FRONT EXTERNAL TEXT PROCEDURE . 59
FRONTCOMPARE EXTERNAL BOOLEAN PROCEDURE 63
FRONTSTRIP EXTERNAL TEXT PROCEDURE 60
GAG TTY bit setting from a SIMULA program 125
Game of cat and mouse . . . . . 27
Garbage collection . . . . . . 51
General Purpose System Simulator (GPSS) in SIMULA 24
GETCH EXTERNAL CHARACTER PROCEDURE 36
GETITEM EXTERNAL TEXT PROCEDURE 60
GETRADIX EXTERNAL INTEGER PROCEDURE 85
GETTAB EXTERNAL PROCEDURE . . . 116
Getting information from another program, TMPIN procedure 124
GETTYPE EXTERNAL INTEGER PROCEDURE 66
GETVIS terminal type enquirer . 26
GPSSS system written in SIMULA 24
GRAPHI, part of FIGURE . . . . 7
Graphic package for tektronix terminals 25
HASH EXTERNAL INTEGER PROCEDURE 66
Help facility in user programs 17
HELP facility, package for providing of 26
Hibernate . . . . . . . . . . . 133
HISTP EXTERNAL PROCEDURE . . . 90
I/O transmission error . . . . 148
IASHIFT EXTERNAL BOOLEAN PROCEDURE 101
IBMSIM Conversion Program . . . 28
IDRX50 EXTERNAL TEXT PROCEDURE 116
IDSIXBIT EXTERNAL TEXT PROCEDURE 116
ILOG EXTERNAL INTEGER PROCEDURE 94
IMAX EXTERNAL INTEGER PROCEDURE 58, 101
IMIN EXTERNAL INTEGER PROCEDURE 58, 101
IMPLEMENTATION EXTERNAL TEXT PROCEDURE 53
Information Retrieval . . . . . 24
INITEM EXTERNAL TEXT PROCEDURE 61
INLINE EXTERNAL TEXT PROCEDURE 88
INORD EXTERNAL TEXT PROCEDURE . 107
Input data checking . . . . . . 17
INPUT EXTERNAL INTEGER PROCEDURE 39, 41
Input of characters from terminal, control of echoing 114
Input of data by form fill in . 26
Input-Output errors . . . . . . 146
INPUT/OUTPUT . . . . . . . . . 35, 87
INPUTCHECK EXTERNAL BOOLEAN PROCEDURE 33
INPUTWAIT EXTERNAL INTEGER PROCEDURE 34
INSINGLECHAR EXTERNAL CHARACTER PROCEDURE 35
INSNGL EXTERNAL CHARACTER PROCEDURE 36
INTEGER to REAL conversion, REAINT procedure 122
Intra-job communication, TMPIN procedure 124
Intra-job communication, TMPOUT procedure 125
INTREA EXTERNAL PROCEDURE . . . 117
ISUM EXTERNAL INTEGER PROCEDURE 94
Job control . . . . . . . . . . 118
Job control, JOBSTATUS procedure 117
Job control, PTYCHECK procedure 119
Job control, PTYFIL procedure . 120
Job control, PTYINIMAGE procedure 120
JOBSTATUS EXTERNAL INTEGER PROCEDURE 117
JUMPERROR procedure . . . . . . 149
LASTLOC EXTERNAL INTEGER PROCEDURE 45
Line-numbered file, input of . 118
LINECOUNT EXTERNAL INTEGER PROCEDURE 35
LITENBOKSTAV EXTERNAL TEXT PROCEDURE 107
LMAX EXTERNAL LONG REAL PROCEDURE 58
LMIN EXTERNAL LONG REAL PROCEDURE 58
LOAD.SIM part of SIMDBM . . . . 23
LOADBYTE EXTERNAL INTEGER PROCEDURE 117
LOADWORD EXTERNAL INTEGER PROCEDURE 117
LOGININFORMATION EXTERNAL TEXT PROCEDURE 54
LOOK EXTERNAL BOOLEAN PROCEDURE 43
LOOKAHEAD EXTERNAL CHARACTER PROCEDURE 87
LOOKUP EXTERNAL BOOLEAN PROCEDURE 68
LOOKUP of files . . . . . . . . 44
LOWCASE EXTERNAL TEXT PROCEDURE 71
LSUM EXTERNAL LONG REAL PROCEDURE 94
MAKEDF program . . . . . . . . 30
MAKETEXT EXTERNAL TEXT PROCEDURE 71
MAKHLP PROGRAM generating DAHELP files 30
MASKERROR procedure . . . . . . 148
MATCH6 EXTERNAL INTEGER PROCEDURE 117
Mathematical function error . . 148
Max and min, IMAX procedure . . 58
Max and min, IMIN procedure . . 58
Max and min, LMAX procedure . . 58
Max and min, LMIN procedure . . 58
Max and min, RMAX procedure . . 58
Max and min, RMIN procedure . . 58
MAXINT EXTERNAL INTEGER PROCEDURE 53
MAXLOC EXTERNAL INTEGER PROCEDURE 45
MAXREAL EXTERNAL LONG REAL PROCEDURE. 53
Memory access without SIMULA checks, LOADBYTE 117
Memory access without SIMULA checks, LOADWORD 117
Memory access without SIMULA checks, STOREBYTE 123
Memory access without SIMULA checks, STOREWORD 124
MEMORY HANDLING . . . . . . . . 51
MENU EXTERNAL BOOLEAN PROCEDURE 67
MENY EXTERNAL BOOLEAN PROCEDURE 107
MIC control from a SIMULA program, CALLMIC procedure 110
MIN AND MAX . . . . . . . . . . 58
Min and max, IMAX procedure . . 58
Min and max, IMIN procedure . . 58
Min and max, LMAX procedure . . 58
Min and max, LMIN procedure . . 58
Min and max, RMAX procedure . . 58
Min and max, RMIN procedure . . 58
MINREAL EXTERNAL LONG REAL PROCEDURE 53
Monitor calls from SIMULA, XCALLI procedure 129
Monitor tables, GETTAB procedure 116
Monitoring . . . . . . . . . . 143
Multi-terminal . . . . . . . . 138
Network, TTYLINE procedure . . 127
Network, TTYNUMBER procedure . 128
NEXTRANDOM EXTERNAL PROCEDURE . 104
NO (FORM, CRLF, GAG, TAB etc.) TTY bit setting 125
Number on input line . . . . . 118
NUMBERED EXTERNAL BOOLEAN PROCEDURE 118
Object input/output . . . . . . 38
OCTAL EXTERNAL TEXT PROCEDURE . 118
ON condition in PL/1 . . . . . 145
OPERATIONS ON TEXTS . . . . . . 69
OUTCHR EXTERNAL PROCEDURE . . . 36
OUTLINE EXTERNAL PROCEDURE . . 87
OUTPUT EXTERNAL INTEGER PROCEDURE 39
Output of CHARACTER immediately 36
Output of TEXT immediately . . 37
Output, forced, to the TTY . . 37
OUTSTRING EXTERNAL PROCEDURE . 37
OUTTIME EXTERNAL PROCEDURE . . 90
Overflow error . . . . . . . . 148
PACK EXTERNAL BOOLEAN PROCEDURE 54
PACKING INTO PARTS OF WORDS . . 54
Parallel processes in the real world 142
PARTITIONING OF TEXTS . . . . . 59
PERGEN EXTERNAL CLASS . . . . . 102
Picture processing . . . . . . 25
PL/1 programming language . . . 145
PREP1.SIM part of SIMDBM . . . 23
Preprocessor in SIMDBM producing SIMULA classes 23
PRIMARY MEMORY HANDLING . . . . 51
Process control . . . . . . . . 142
Program measurement system FQC 29
PTY handling . . . . . . . . . 118
PTY handling, JOBSTATUS procedure 117
PTY handling, PTYCHECK procedure 119
PTY handling, PTYFIL procedure 120
PTY handling, PTYINIMAGE procedure 120
PTYCHECK EXTERNAL INTEGER PROCEDURE 119
PTYFIL EXTERNAL INTEGER PROCEDURE 120
PTYINIMAGE EXTERNAL INTEGER PROCEDURE 120
PUTFLOAT EXTERNAL TEXT PROCEDURE 77
PUTSIZE EXTERNAL INTEGER PROCEDURE 42
PUTTEXT EXTERNAL BOOLEAN PROCEDURE 70
PUTTIME EXTERNAL TEXT PROCEDURE 75
QASETE question-answering demo program 27
QSIM demo program, doctor's waiting room 27
Question-answering demo program 27
QUEUE system simulation using GPSSS 24
RADIX EXTERNAL TEXT PROCEDURE . 84
Radix50 conversion, RDX50 procedure 121
RADIX50 to ASCII conversion, IDRX50 procedure 116
RADIX50 to SIXBIT code, SXRX50 procedure 123
RANDOM EXTERNAL REAL PROCEDURE 103
RANDOM NUMBER GENERATION ETC. . 102
Range error for array index . . 148
RDX50 EXTERNAL PROCEDURE . . . 121
Reaction time . . . . . . . . . 140
READ errors . . . . . . . . . . 146
READ EXTERNAL PROCEDURE . . . . 37
REAINT EXTERNAL PROCEDURE . . . 122
REAL to INTEGER conversion, INTREA procedure 117
REAL-TIME FOR MULTI-TERMINAL SIMULTANEOUS I/O. 32
REALTIME EXTERNAL SIMULATION CLASS 130
Receiving information from another program, TMPIN procedure 124
Record input/output . . . . . . 38
Recovery after error . . . . . 145
REL file information, RDX50 procedure 121
Release version . . . . . . . . 1
RENAME EXTERNAL INTEGER PROCEDURE 120
Renaming a file, RENAME procedure 120
REQUEST EXTERNAL TEXT PROCEDURE 88
RESCAN EXTERNAL BOOLEAN PROCEDURE 122
Reseterror procedure . . . . . 150
Responsibility for errors . . . 2
REST EXTERNAL TEXT PROCEDURE . 59
RESTORE EXTERNAL PROCEDURE . . 49
REWIND of magtapes . . . . . . 44
RMAX EXTERNAL REAL PROCEDURE . 58
RMIN EXTERNAL REAL PROCEDURE . 58
ROUTINES WRITEABLE IN SIMULA. . 59
RSUM EXTERNAL REAL PROCEDURE . 94
RUBOUT, part of FIGURE . . . . 7
RUN EXTERNAL PROCEDURE . . . . 47
SAFEI EXTERNAL CLASS . . . . . 22
SAFEIO conversational i/o package 17
SAFEIO EXTERNAL CLASS . . . . . 17
SAFMIN EXTERNAL CLASS . . . . . 22
SAVE EXTERNAL INTEGER PROCEDURE 48
SCALESTEP EXTERNAL REAL PROCEDURE 100
SCAN EXTERNAL INTEGER PROCEDURE, see also DECOM 79
SCANFRAC EXTERNAL INTEGER PROCEDURE 70
SCANINT EXTERNAL INTEGER PROCEDURE 69
SCANREAL EXTERNAL LONG REAL PROCEDURE 69
SCANTO EXTERNAL TEXT PROCEDURE 62
SCHEDULING AND JOB CONTROL . . 47
SCHEMA, entering into a data base 23
SCRAMBLE EXTERNAL PROCEDURE . . 102
SCRATCHFILE EXTERNAL BOOLEAN PROCEDURE 44
Scratching a file, RENAME procedure 120
Scratching files . . . . . . . 44
SEARCH EXTERNAL INTEGER PROCEDURE 63
Search with Boolean condition . 24
SEARCHING AND TESTING OF TEXTS 62
Segmentation into overlayed core code segments 52
SELECT EXTERNAL CLASS . . . . . 24
Semaphore . . . . . . . . . . . 142
Sending information to another program, TMPOUT procedure 125
SENSEERROR procedure . . . . . 150
Sequentail file to DIRECTFILE conversion 30
SET TTY performed from a SIMULA program 125
SFD sorting, SORTDN procedure . 99
SFD-file handling . . . . . . . 113
SHIP demo program, troup transport simulation 27
SIGMA2 EXTERNAL REAL PROCEDURE 95
SIGMEAN EXTERNAL PROCEDURE . . 96
SIMATR program for displaying attribute files 123
SIMDBM data base query system . 23
SIMDBM files on the distribution tape 23
SIMDBM system . . . . . . . . . 22
SIMDBM, ARRLGD utility procedure 86
SIMDBM, ARRTXT utility procedure 86
SIMDBM, class DBMMIN . . . . . 23
SIMDBM, class FETCH.SIM . . . . 23
SIMDBM, routine LOAD.SIM . . . 23
SIMDBM, routine PREP1.SIM . . . 23
SIMDDT demo program DDTDEM . . 27
SIMDDT, procedure for calling . 46
SIMDEM demo programs . . . . . 27
SIMED SIMULA Program Editor . . 28
SIMEI EXTERNAL SIMULATION CLASS 22
SIMEIO EXTERNAL SIMULATION CLASS 22
SIMEXP program for merging source files 28
SIMIBM Conversion Program . . . 28
SIMMIN EXTERNAL SIMULATION CLASS 22
SIMSTR SIMULA PROGRAM Stripper 28
SIMULA SOURCE PROGRAM CONVERSION PROGRAMS 28
Simulation demo program . . . . 27
Simulation of cat and mouse game 27
Simulation of doctor's waiting room 27
Simulation of troup transport . 27
SIXBIT EXTERNAL INTEGER PROCEDURE 123
SIXBIT from RADIX50, SXRX50 procedure 123
SIXBIT match with "wildcards", MATCH6 procedure 117
SIXBIT to ASCII conversion, IDSIXBIT procedure 116
SKIP EXTERNAL TEXT PROCEDURE . 63
SLEEP EXTERNAL PROCEDURE . . . 34
SORT PROCEDURES . . . . . . . . 97
SORTDN EXTERNAL PROCEDURE for sorting 2-dim integer array 99
Sorting a 2-dimensional integer array, SORTDN procedure 99
SORTING AND SUMMATION ETC. . . 94
SORTTA EXTERNAL PROCEDURE . . . 97
SORTTD EXTERNAL PROCEDURE . . . 98
SPLIT EXTERNAL PROCEDURE . . . 72
SPLITA EXTERNAL INTEGER PROCEDURE 73
SPLITC EXTERNAL INTEGER PROCEDURE 73
SQHELP EXTERNAL BOOLEAN PROCEDURE 26
SSCAN version of SCAN . . . . . 83
STARTPOS EXTERNAL INTEGER PROCEDURE 72
STAT1E simulation demo program 27
STAT2E simulation demo program 27
Status query . . . . . . . . . 143
STOP, immediate, of execution . 50
STORBOKSTAV EXTERNAL TEXT PROCEDURE 107
STORE data base handling package 23
STOREBYTE EXTERNAL INTEGER PROCEDURE 123
STOREWORD EXTERNAL INTEGER PROCEDURE 124
Structure of a SIMULA program, output of 123
Structured programming . . . . 27
Subjob control . . . . . . . . 118
Subjob control, JOBSTATUS procedure 117
Subjob control, PTYCHECK procedure 119
Subjob control, PTYFIL procedure 120
Subjob control, PTYINIMAGE procedure 120
SUBMIT EXTERNAL BOOLEAN PROCEDURE 48
SUMMARY LIST OF ROUTINES . . . 7
SWAP EXTERNAL PROCEDURE . . . . 52
SWEDISH LANGUAGE TEXT HANDLING AND INPUT/OUTPUT 107
SXRX50 EXTERNAL INTEGER PROCEDURE 123
Synchronize . . . . . . . . . . 133
TAB TTY bit setting from a SIMULA program 125
TABLE package, test of formula data collection 27
TAGORD EXTERNAL TEXT PROCEDURE 107
TAGTYP EXTERNAL INTEGER PROCEDURE 107
Tektronix terminal graphics package 25
Terminal character input, control of echoing 114
Terminal communication, TRMOP procedure 125
Terminal input data checking . 17
Terminal type enquiry . . . . . 26
Test programs . . . . . . . . . 27
Text editing of SIMULA direct access files 23
Text editing on directfiles . . 30
TEXT handling . . . . . . . . . 59
Text transformation from ASCII to SIXBIT 116
Text value comparison . . . . . 63
TIME AND DATE . . . . . . . . . 31
TIMELIMIT EXTERNAL PROCEDURE . 32
TMP:TRM file containing terminal type identification 26
TMPCOR input, TMPIN procedure . 124
TMPCOR output, TMPOUT procedure 125
TMPIN EXTERNAL TEXT PROCEDURE . 124
TMPNAM EXTERNAL TEXT PROCEDURE 124
TMPOUT EXTERNAL BOOLEAN PROCEDURE 125
TODAY EXTERNAL TEXT PROCEDURE . 31
TOPS-10 directory file handling, DIRHND class 113
Transferring control to another program, RUN procedure 47
Transmission of data, errors . 146
TRMOP EXTERNAL INTEGER PROCEDURE 125
TSUB EXTERNAL TEXT PROCEDURE . 60
TTY (.SET TTY) performed from a SIMULA program 125
TTY line number in DEC-10 network, TTYLINE procedure 127
TTY number in DEC-10 network, TTYNUMBER procedure 128
TTYCHECK EXTERNAL BOOLEAN PROCEDURE 36
TTYLINE external procedure . . 127
TTYNUMBER external procedure . 128
Type conversion, INTREA procedure 117
Type conversion, REAINT procedure 122
UFD sorting, SORTDN procedure . 99
UFD-file handling . . . . . . . 113
Unchecked memory access, LOADBYTE procedure 117
Unchecked memory access, LOADWORD 117
Unchecked memory access, STOREBYTE 123
Unchecked memory access, STOREWORD 124
Underflow error . . . . . . . . 148
UNFORMATTED (BINARY) I/O. . . . 38
Unformatted input/output . . . 38
UNIQUE EXTERNAL INTEGER PROCEDURE 103
UNLOAD of magtapes . . . . . . 44
UNPACK EXTERNAL BOOLEAN PROCEDURE 54
Unpacking a field from a 36-bit word, BITFIELD procedure 109
Unrestricted access to core, ABSADR procedure 108
UPCASE EXTERNAL TEXT PROCEDURE 71
UPCOMPARE EXTERNAL BOOLEAN PROCEDURE 63
UPTO EXTERNAL TEXT PROCEDURE . 59
UTILITY PACKAGES . . . . . . . 17
VIRTUAL MEMORY HANDLING . . . . 52
VIRTUAL MEMORY HANDLING (OR OVERLAY FACILITY) 52
VISTA EXTERNAL CLASS . . . . . 25
VISTA package, applications . . 27
Wait . . . . . . . . . . . . . 133
Wild card match, MATCH6 procedure 117
WILDSIX EXTERNAL INTEGER PROCEDURE 129
WRITE errors . . . . . . . . . 146
WRITE EXTERNAL PROCEDURE . . . 38
XCALLI EXTERNAL INTEGER PROCEDURE 129
ZIMSET EXTERNAL CLASS (SIMSET) 105
ZIMULATION EXTERNAL CLASS (SIMULATION) 105
^C, simulated from program . . 50
^O bit resetting . . . . . . . 45