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updated for new Basic compiler

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ceriel 1988-07-04 13:19:09 +00:00
parent 93bdacae44
commit 0cf8ad9930
3 changed files with 189 additions and 94 deletions
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3
distr/Action
View file

@ -7,9 +7,6 @@ end
name "Pascal bootstrap files"
dir lang/pc/pem
end
name "Basic yacc files"
dir lang/basic/src
end
name "C compiler makefile"
dir lang/cem/cemcom
action "cp AckMake makefile"

2
distr/Exceptions
View file

@ -2,8 +2,6 @@
-- ./h/em_mnem.h no RCS file
-- ./h/em_pseu.h no RCS file
-- ./h/em_spec.h no RCS file
-- ./lang/basic/src/y.tab.c no RCS file
-- ./lang/basic/src/y.tab.h no RCS file
-- ./lang/cem/cemcom/makefile no RCS file
-- ./lang/pc/pem/pem22.m no RCS file
-- ./lang/pc/pem/pem24.m no RCS file

278
doc/basic.doc
View file

@ -1,5 +1,5 @@
.\" $Header$
.TL
.\" $Header$
.TL
.de Sy
.LP
.IP \fBsyntax\fR 10
@ -13,10 +13,17 @@
The ABC compiler
.AU
Martin L. Kersten
Gert-Jan Akkerman
Marcel Worring
Edo Westerhuis
Frans Kunst
Ronnie Lachniet
.AI
Department of Mathematics and Computer Science.
.br
Vrije Universiteit
Free University
.br
Amsterdam
.AB
This manual describes the
programming language BASIC and its compiler
@ -28,35 +35,40 @@ INTRODUCTION.
The BASIC-EM compiler is an extensive implementation of the
programming language BASIC.
The language structure and semantics are modelled after the
BASIC interpreter/compiler of Microsoft (tr), a detailed comparison
BASIC interpreter/compiler of Microsoft (tr), a short comparison
is provided in appendix A.
.LP
The compiler generates code for a virtual machine, the EM machine
[[ACM, etc]]
[[ACM, etc]].
Using EM as an intermediate machine results in a highly portable
compiler and BASIC code.
.br
The drawback of EM is that it does not directly reflect one particular
hardware design, which means that many of
the low level operations available within
BASIC are ill-defined or even inapplicable.
hardware design, which means that many of the low level operations available
within BASIC are ill-defined or even inapplicable.
To mention a few, the peek and poke instructions are likely
to be behave errorneous, while line printer and tapedeck
primitives are unknown.
.LP
This manual is divided into three chapters.
The first chapter discusses the general language syntax and semantics.
Chapter two describes the statements available in BASIC-EM.
Chapter 3 describes the predefined functions,
ordered alphabetically.
Appendix A discusses the differences with
Microsoft BASIC. Appendix B describes all reserved symbols.
Appendix C lists the error messages in use.
.br
Chapter 1 discusses the general language syntax and semantics.
.br
Chapter 2 describes the statements available in BASIC-EM.
.br
Chapter 3 describes the predefined functions, ordered alphabetically.
.LP
Appendix A discusses the differences with Microsoft BASIC.
.br
Appendix B describes all reserved symbols.
.LP
.LP
.SH
SYNTAX NOTATION
.LP
The conventions for syntax presentation are as follows:
.IP CAPS 10
Items are reserved words, must be input as shown
Items are reserved words, must be input as shown.
.IP <> 10
Items in lowercase letters enclosed in angular brackets
are to be supplied by the user.
@ -71,6 +83,7 @@ must be chosen.
Vertical bars separate the choices within braces.
.LP
All punctuation must be included where shown.
.bp
.NH 1
GENERAL INFORMATION
.LP
@ -81,7 +94,7 @@ an executable file, called a.out.
LINE FORMAT
.LP
A BASIC program consists of a series of lines, starting with a
positive line number in the range 0 to 65529.
positive line number in the range 0 to 32767.
A line may consists of more then one physical line on your terminal, but must
is limited to 1024 characters.
Multiple BASIC statements may be placed on a single line, provided
@ -105,19 +118,24 @@ character set enclosed by double quotation marks.
Numeric constants are positive or negative numbers, grouped into
five different classes.
.IP "a) integer constants" 25
.br
Whole numbers in the range of -32768 and 32767. Integer constants do
not contain decimal points.
.IP "b) fixed point constants" 25
.br
Positive or negative real numbers, i.e. numbers with a decimal point.
.IP "c) floating point constants" 25
.br
Real numbers in scientific notation. A floating point constant
consists of an optional signed integer or fixed point number
followed by the letter E (or D) and an optional signed integer
(the exponent).
The allowable range of floating point constants is 10^-38 to 10^+38.
.IP "d) Hex constants" 25
.br
Hexadecimal numbers, denoted by the prefix &H.
.IP "d) Octal constants" 25
.IP "e) Octal constants" 25
.br
Octal numbers, denoted by the prefix &O.
.NH 2
VARIABLES
@ -128,7 +146,7 @@ Before a variable is assigned its value is assumed to be zero.
.br
Variable names are composed of letters, digits or the decimal point,
starting with a letter. Up to 40 characters are significant.
A variable name be be followed by any of the following type
A variable name can be followed by any of the following type
declaration characters:
.IP % 5
Defines an integer variable
@ -139,11 +157,7 @@ Defines a double precision variable
.IP $ 5
Defines a string variable.
.LP
NOTE: Two variables with the same name but different type is
considered illegal.
.LP
Beside single valued variables, values may be grouped
into tables or arrays.
Beside single valued variables, values may be grouped into tables or arrays.
Each element in an array is referenced by the array name and an index,
such a variable is called a subscripted variable.
An array has as many subscripts as there are dimensions in the array,
@ -154,14 +168,25 @@ function.
.br
A variable name may not be a reserved word nor the name
of a predefined function.
A list of all reserved identifiers is included as Appendix ?.
A list of all reserved identifiers is included as Appendix B.
.LP
NOTES:
.br
Two variables with the same name but different type is
considered illegal.
.br
The type of a variable without typedeclaration-character is set,
at it's first occurence in the program,
to the defaulttype which is (in this implementation) double precision.
.br
Multi-dimensional array's must be declared before use (see
DIM-statement ).
.br
BASIC-EM differs from Microsoft BASIC in supporting floats in one precision
only (due to EM), eg doubles and floats have the same precision.
.NH 2
EXPRESSIONS
.LP
BASIC-EM differs from Microsoft BASIC in supporting floats in one precision
only (due to EM).
All floating point constants have the same precision, i.e. 16 digits.
.LP
When necessary the compiler will convert a numeric value from
one type to another.
A value is always converted to the precision of the variable it is assigned
@ -179,9 +204,9 @@ Arithmetic
.LP
The arithmetic operators in order of precedence,a re:
.DS L
\^ Exponentiation
^ Exponentiation
- Negation
*,/,\\,MOD Multiplication, Division, Remainder
*,/,\\\\\\\\,MOD Multiplication, Division, Remainder
+,- Addition, Substraction
.DE
The operator \\\\ denotes integer division, its operands are rounded to
@ -189,7 +214,7 @@ integers before the operator is applied.
Modulus arithmetic is denoted by the operator MOD, which yields the
integer value that is the remainder of an integer division.
.br
The order in which operators are performed can be changec with parentheses.
The order in which operators are performed can be changed with parentheses.
.SH
Relational
.LP
@ -210,7 +235,7 @@ then the arithmetic operators.
Logical
.LP
The logical operators performs tests on multiple relations, bit manipulations,
or Boolean operations.
or boolean operations.
The logical operators returns a bitwise result ("true" or "false").
In an expression, logical operators are performed after the relational and
arithmetic operators.
@ -241,6 +266,7 @@ ERROR MESSAGES
.LP
The occurence of an error results in termination of the program
unless an ON....ERROR statement has been encountered.
.bp
.NH 1
B-EM STATEMENTS
.LP
@ -266,7 +292,7 @@ The argument list consist of (subscripted) variables.
The BASIC compiler pushes the address of the arguments on the stack in order
of encounter.
.RM
Not yet available
Not yet available.
.NH 2
CLOSE
.Sy
@ -274,7 +300,7 @@ CLOSE [[#]<file number>[,[#]<file number...>]]
.PU
To terminate I/O on a disk file.
<file number> is the number associated with the file
when it was OPENed (See OPEN). Ommission of parameters results in closing
when it was OPENed (See OPEN-statement). Ommission of parameters results in closing
all files.
.sp
The END statement and STOP statement always issue a CLOSE of
@ -334,14 +360,15 @@ DIM <list of subscripted variable>
.PU
The DIM statement allocates storage for subscripted variables.
If an undefined subscripted variable is used
the maximum value of the array subscript(s) is assumed to be 10.
A subscript out of range is signalled by the program (when RCK works)
the maximum value of the array subscript is assumed to be 10.
A subscript out of range is signalled by the program (when ACK works)
The minimum subscript value is 0, unless the OPTION BASE statement has been
encountered.
.sp
All variables in a subscripted variable are initially zero.
.sp
BUG. Multi-dimensional arrays MUST be defined.
BUGS. Multi-dimensional arrays MUST be defined. Subscript out of range is
left unnotified.
.NH 2
END
.Sy
@ -351,6 +378,10 @@ END terminates a BASIC program and returns to the UNIX shell.
An END statement at the end of the BASIC program is optional.
.NH 2
ERR and ERL
.Sy
<identifier name>= ERR
.br
<identifier name>= ERL
.PU
Whenever an error occurs the variable ERR contains the
error number and ERL the BASIC line where the error occurred.
@ -364,8 +395,7 @@ ERROR <integer expression>
To simulate the occurrence of a BASIC error.
To define your own error code use a value not already in
use by the BASIC runtime system.
The list of error messages currently in use
can be found in appendix B.
The list of error messages currently in use can be found in appendix B.
.NH 2
FIELD
.PU
@ -383,18 +413,15 @@ The FOR statements allows a series of statements to be performed
repeatedly. <variable> is used as a counter. During the first
execution pass it is assigned the value <low>,
an arithmetic expression. After each pass the counter
is incremented with the step size <size>, an expression.
is incremented (decremented) with the step size <size>, an expression.
Ommission of the step size is intepreted as an increment of 1.
.br
Execution of the program lines specified between the FOR and the NEXT
statement is terminated as soon as <low> is greater than <high>
statement is terminated as soon as <low> is greater (less) than <high>
.sp
The NEXT statement is labeled with the name(s) of the counter to be
incremented.
.sp
The body of the FOR statement is skipped when the initial value of the
loop times the sign of the step exceeds the value of the highest value
times the sign of the step.
.sp
The variables mentioned in the NEXT statement may be ommitted, in which case
the variable of increment the counter of the most recent FOR statement.
If a NEXT statement is encountered before its corresponding FOR statement,
@ -408,7 +435,7 @@ To be implemented.
.NH 2
GOSUB...RETURN
.Sy
GOSUB <line number
GOSUB <line number>
...
.br
RETURN
@ -512,7 +539,7 @@ LET
[LET]<variable>=<expression>
.PU
To assign the value of an expression to a (subscribted) variable.
The type convertions as dictated in section 1.X apply.
The type convertions as dictated in chapter 1 apply.
.NH 2
LINE INPUT
.Sy
@ -558,18 +585,30 @@ Subsequent errors result in an error message and program termination.
ON...GOSUB and ON ...GOTO
.Sy
ON <expression> GOSUB <list of line numbers>
.br
ON <expression> GOTO <list of line numbers>
.PU
To branch to one of several specified line numbers or subroutines, based
on the result of the <expression>. The list of line numbers are considered
the first, second, etc alternative. Branching to the first occurs when
the expression evaluates to one, to the second alternative on two, etc.
If the value of the expression in zero or greater than the number of alternatives, processing continues at the first statement following the ON..GOTO
If the value of the expression is zero or greater than the number of alternatives, processing continues at the first statement following the ON..GOTO
(ON GOSUB) statement.
.sp
When the expression results in a negative number the
an "Illegal function call" error occurs.
.sp
BUG If the value of the expression is zero or greater than the number of
alternatives, processing does NOT continue at the first statement
following the ON..GOTO (ON GOSUB) statement.
.NH 2
OPEN
.Sy
OPEN {"i" | "o" | "r" } , [#]<file number> , <file-name>
.PU
To open <file-name> (filename should be quoted) for input/reading or output.
If file is not opened for output it has to be existent, otherwise an
"file not found" error will occur.
.NH 2
OPTION BASE
.Sy
@ -587,7 +626,21 @@ because it requires full understanding of both
the implementation of the Amsterdam
Compiler Kit and the hardware characteristics.
.NH 2
PRINT [USING]
PRINT
.Sy
PRINT <list of variables and/or constants>
.PU
To print constants or the contents of variables on the terminal-device.
If the variables or constants are seperated by comma's the values will
be printed seperated by tabs.
If the variables or constants are seperated by semi-colon's the values
will be printed without spaces in between.
The new-line generated at the end of the print-statement can be suppressed by
a semi-colon at the end of list of variables or constants.
.NH 2
PRINT USING
.PU
To be implemented
.NH 2
PUT
.PU
@ -608,7 +661,8 @@ READ <list of variables>
.PU
To read values from the DATA statements and assign them to variables.
The type of the variables should match to the type of the items being read,
otherwise a "Syntax error" occurs.
otherwise a "Syntax error" occurs. If all data is read the message "Out of
data" will be displayed.
.NH 2
REM
.Sy
@ -651,6 +705,8 @@ SWAP
SWAP <variable>,<variable>
.PU
To exchange the values of two variables.
.sp
BUG. Strings cannot be swapped !
.NH 2
TRON/TROFF
.Sy
@ -684,118 +740,121 @@ WRITE #<file number> ,<list of expressions>
.PU
To write a sequential data file, being opened with the "O" mode.
The values are being writting using the DATA statements layout conventions.
.bp
.NH
FUNCTIONS
.LP
.IP ABS(X) 12
.IP ABS(X) 25
Returns the absolute value of expression X
.IP ASC(X$) 12
.IP ASC(X$) 25
Returns the numeric value of the first character of the string.
If X$ is not initialized an "Illegal function call" error
is returned.
.IP ATN(X) 12
.IP ATN(X) 25
Returns the arctangent of X in radians. Result is in the range
of -pi/2 to pi/2.
.IP CDBL(X) 12
.IP CDBL(X) 25
Converts X to a double precision number.
.IP CHR$(X) 12
.IP CHR$(X) 25
Converts the integer value X to its ASCII character.
X must be in the range of 0 to 127.
X must be in the range of 0 to 257.
It is used for cursor addressing and generating bel signals.
.IP CINT(X) 12
.IP CINT(X) 25
Converts X to an integer by rounding the fractional portion.
If X is not in the range -32768 to 32767 an "Overflow"
error occurs.
.IP COS(X) 12
.IP COS(X) 25
Returns the cosine of X in radians.
.IP CSNG(X) 12
Converts X to a double precision number.
.IP CVI(<2-bytes>) 12
.IP CSNG(X) 25
Converts X to a single precision number.
.IP CVI(<2-bytes>) 25
Convert two byte string value to integer number.
.IP CVS(<4-bytes>) 12
.IP CVS(<4-bytes>) 25
Convert four byte string value to single precision number.
.IP CVD(<8-bytes>) 12
.IP CVD(<8-bytes>) 25
Convert eight byte string value to double precision number.
.IP EOF[(<file-number>)] 12
.IP EOF[(<file-number>)] 25
Returns -1 (true) if the end of a sequential file has been reached.
.IP EXP(X) 12
.IP EXP(X) 25
Returns e(base of natural logarithm) to the power of X.
X should be less then 10000.0.
.IP FIX(X) 12
.IP FIX(X) 25
Returns the truncated integer part of X. FIX(X) is
equivalent to SGN(X)*INT(ABS(X)).
The major difference between FIX and INT is that FIX does not
return the next lower number for negative X.
.IP HEX$(X) 12
.IP HEX$(X) 25
Returns the string which represents the hexadecimal value of
the decimal argument. X is rounded to an integer using CINT
before HEX$ is evaluated.
.IP INT(X) 12
.IP INT(X) 25
Returns the largest integer <= X.
.IP INPUT$(X[,[#]Y]) 12
.IP INP$(X[,[#]Y]) 25
Returns the string of X characters read from the terminal or
the designated file.
.IP LEX(X$) 12
.IP LEN(X$) 25
Returns the number of characters in the string X$.
Non printable and blancs are counted too.
.IP LOC(<file\ number>) 12
.IP LOC(<file\ number>) 25
For sequential files LOC returns
position of the read/write head, counted in number of bytes.
For random files the function returns the record number just
read or written from a GET or PUT statement.
If nothing was read or written 0 is returned.
.IP LOG(X) 12
.IP LOG(X) 25
Returns the natural logarithm of X. X must be greater than zero.
.IP MID$(X,I,[J]) 12
To be implemented.
.IP MKI$(X) 12
.IP MID$(X,I,[J]) 25
Returns first J characters from string X starting at position I in X.
If J is omitted all characters starting of from position I in X are returned.
.IP MKI$(X) 25
Converts an integer expression to a two-byte string.
.IP MKS$(X) 12
.IP MKS$(X) 25
Converts a single precision expression to a four-byte string.
.IP MKD$(X) 12
.IP MKD$(X) 25
Converts a double precision expression to a eight-byte string.
.IP OCT$(X) 12
.IP OCT$(X) 25
Returns the string which represents the octal value of the decimal
argument. X is rounded to an integer using CINT before OCTS is evaluated.
.IP PEEK(I) 12
.IP PEEK(I) 25
Returns the byte read from the indicated memory. (Of limited use
in the context of ACK)
.IP POS(I) 12
.IP POS(I) 25
Returns the current cursor position. To be implemented.
.IP RIGHT$(X$,I)
Returns the right most I characters of string X$.
If I=0 then the empty string is returned.
.IP RND(X) 12
.IP RND(X) 25
Returns a random number between 0 and 1. X is a dummy argument.
.IP SGN(X) 12
.IP SGN(X) 25
If X>0 , SGN(X) returns 1.
.br
if X=0, SGN(X) returns 0.
.br
if X<0, SGN(X) returns -1.
.IP SIN(X) 12
.IP SIN(X) 25
Returns the sine of X in radians.
.IP SPACE$(X) 12
.IP SPACE$(X) 25
Returns a string of spaces length X. The expression
X is rounded to an integer using CINT.
.IP STR$(X)
Returns the string representation value of X.
.IP STRING$(I,J) 12
.IP STRING$(I,J) 25
Returns thes string of length Iwhose characters all
have ASCII code J. (or first character when J is a string)
.IP TAB(I) 12
.IP TAB(I) 25
Spaces to position I on the terminal. If the current
print position is already beyond space I,TAB
goes to that position on the next line.
Space 1 is leftmost position, and the rightmost position
is width minus 1. To be used within PRINT statements only.
.IP TAN(X) 12
.IP TAN(X) 25
Returns the tangent of X in radians. If TAN overflows
the "Overflow" message is displayed.
.IP VAL(X$) 12
.IP VAL(X$) 25
Returns the numerical value of string X$.
The VAL function strips leading blanks and tabs from the
argument string.
.bp
.SH
APPENDIX A DIFFERENCES WITH MICROSOFT BASIC
.LP
@ -847,3 +906,44 @@ LSET
RSET
PUT
.DE
.bp
.SH
APPENDIX B RESERVED WORDS IN BASIC-EM
.LP
The following list of words/symbols/names/identifiers are reserved, which
means that they can not be used for variable-names.
.DS
ABS AND ASC AS
ATN AUTO BASE CALL
CDBL CHAIN CHR CINT
CLEAR CLOAD CLOSE COMMON
CONT COS CSNG CSAVE
CVI CVS CVD DATA
DEFINT DEFSNG DEFDBL DEFSTR
DEF DELETE DIM EDIT
ELSE END EOF ERASE
ERROR ERR ERL ELSE
EQV EXP FIELD FIX
FOR FRE GET GOSUB
GOTO HEX IF IMP
INKEY INPUT INP INSTR
INT KILL LEFT LEN
LET LINE LIST LLIST
LOAD LOC LOG LPOS
LPRINT LSET MERGE MID
MKI MKS MKD MOD
NAME NEW NEXT NOT
NULL ON OCT OPEN
OPTION OR OUT PEEK
POKE PRINT POS PUT
RANDOMIZE READ REM RENUM
REN RESTORE RESUME RETURN
RIGHT RND RUN SAVE
STEP SGN SIN SPACE
SPC SQR STOP STRING
STR SWAP TAB TAN
THEN TO TRON TROFF
USING USR VAL VARPTR
WAIT WHILE WEND WIDTH
WRITE XOR
.DE