137 lines
1.6 KiB
Plaintext
137 lines
1.6 KiB
Plaintext
/*
|
|
* (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
|
|
* See the copyright notice in the ACK home directory, in the file "Copyright".
|
|
*
|
|
* Author: Ceriel J.H. Jacobs
|
|
*/
|
|
|
|
/* S T A T E M E N T S */
|
|
|
|
/* stripped down version from the one in the Modula-2 compiler */
|
|
|
|
/* $Header$ */
|
|
|
|
{
|
|
#include "idf.h"
|
|
#include "LLlex.h"
|
|
|
|
static int loopcount;
|
|
}
|
|
|
|
statement :
|
|
[
|
|
/*
|
|
* This part is not in the reference grammar. The reference grammar
|
|
* states : assignment | ProcedureCall | ...
|
|
* but this gives LL(1) conflicts
|
|
*/
|
|
designator
|
|
[
|
|
ActualParameters?
|
|
|
|
|
[ BECOMES
|
|
| '=' { error("':=' expected instead of '='");
|
|
DOT = BECOMES;
|
|
}
|
|
]
|
|
expression
|
|
]
|
|
/*
|
|
* end of changed part
|
|
*/
|
|
|
|
|
IfStatement
|
|
|
|
|
CaseStatement
|
|
|
|
|
WHILE
|
|
expression
|
|
DO
|
|
StatementSequence
|
|
END
|
|
|
|
|
REPEAT
|
|
StatementSequence
|
|
UNTIL
|
|
expression
|
|
|
|
|
{ loopcount++; }
|
|
LOOP
|
|
StatementSequence
|
|
END
|
|
{ loopcount--; }
|
|
|
|
|
ForStatement
|
|
|
|
|
WithStatement
|
|
|
|
|
EXIT
|
|
{ if (!loopcount) error("EXIT not in a LOOP"); }
|
|
|
|
|
ReturnStatement
|
|
|
|
|
/* empty */
|
|
]
|
|
;
|
|
|
|
StatementSequence :
|
|
statement
|
|
[ %persistent
|
|
';'
|
|
statement
|
|
]*
|
|
;
|
|
|
|
IfStatement :
|
|
IF expression
|
|
THEN StatementSequence
|
|
[
|
|
ELSIF expression
|
|
THEN StatementSequence
|
|
]*
|
|
[
|
|
ELSE StatementSequence
|
|
]?
|
|
END
|
|
;
|
|
|
|
CaseStatement :
|
|
CASE expression
|
|
OF case
|
|
[
|
|
'|' case
|
|
]*
|
|
[ ELSE StatementSequence
|
|
]?
|
|
END
|
|
;
|
|
|
|
case :
|
|
[ CaseLabelList ':'
|
|
StatementSequence
|
|
]?
|
|
;
|
|
|
|
ForStatement :
|
|
FOR IDENT BECOMES expression TO expression
|
|
[
|
|
BY ConstExpression
|
|
|
|
|
]
|
|
DO StatementSequence
|
|
END
|
|
;
|
|
|
|
WithStatement :
|
|
WITH designator DO StatementSequence
|
|
END
|
|
;
|
|
|
|
ReturnStatement :
|
|
RETURN
|
|
[
|
|
expression
|
|
|
|
|
]
|
|
;
|