updated for new Basic compiler

distr/Action

@@ -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"

distr/Exceptions

@@ -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

doc/basic.doc

@@ -1,5 +1,5 @@
-.\" $Header$
+.\" $Header$ 
-.TL
+.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 
+hardware design, which means that many of the low level operations available 
-the low level operations available within 
+within BASIC are ill-defined or even inapplicable.
-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.
+.br
-Chapter two describes the statements available in BASIC-EM.
+Chapter 1 discusses the general language syntax and semantics.
-Chapter 3 describes the predefined functions,
+.br
-ordered alphabetically.
+Chapter 2 describes the statements available in BASIC-EM.
-Appendix A discusses the differences with
+.br
-Microsoft BASIC. Appendix B describes all reserved symbols.
+Chapter 3 describes the predefined functions, ordered alphabetically.
-Appendix C lists the error messages in use.
+.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
+Beside single valued variables, values may be grouped into tables or arrays.
-considered illegal.
-.LP
-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.
+the maximum value of the array subscript is assumed to be 10.
-A subscript out of range is signalled by the program (when RCK works)
+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 
+The list of error messages currently in use can be found in appendix B.
-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
+.IP CSNG(X) 25
-Converts X to a double precision number.
+Converts X to a single precision number.
-.IP CVI(<2-bytes>) 12
+.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
+.IP MID$(X,I,[J]) 25
-To be implemented.
+Returns first J characters from string X starting at position I in X.
-.IP MKI$(X) 12
+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