150 lines
1.5 KiB
Text
150 lines
1.5 KiB
Text
/*
|
|
* (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
|
|
*/
|
|
|
|
/* E X P R E S S I O N S */
|
|
|
|
/* stripped down version of the one in the Modula-2 compiler */
|
|
|
|
/* $Header$ */
|
|
|
|
qualident :
|
|
IDENT
|
|
[
|
|
selector
|
|
]*
|
|
;
|
|
|
|
selector :
|
|
'.' IDENT
|
|
;
|
|
|
|
ExpList :
|
|
expression
|
|
[
|
|
',' expression
|
|
]*
|
|
;
|
|
|
|
ConstExpression :
|
|
expression
|
|
/*
|
|
* Changed rule in new Modula-2.
|
|
*/
|
|
;
|
|
|
|
expression :
|
|
SimpleExpression
|
|
[
|
|
/* relation */
|
|
[ '=' | '#' | '<' | LESSEQUAL | '>' | GREATEREQUAL | IN ]
|
|
SimpleExpression
|
|
|
|
|
/* empty */
|
|
]
|
|
;
|
|
|
|
SimpleExpression :
|
|
[
|
|
'+'
|
|
|
|
|
'-'
|
|
|
|
|
/* empty */
|
|
]
|
|
term
|
|
[
|
|
/* AddOperator */
|
|
[ '+' | '-' | OR ] term
|
|
]*
|
|
;
|
|
|
|
term :
|
|
factor
|
|
[
|
|
/* MulOperator */
|
|
[ '*' | '/' | DIV | MOD | AND ] factor
|
|
]*
|
|
;
|
|
|
|
factor :
|
|
qualident
|
|
[
|
|
designator_tail?
|
|
[
|
|
ActualParameters
|
|
|
|
|
/* empty */
|
|
]
|
|
|
|
|
bare_set
|
|
]
|
|
|
|
|
bare_set
|
|
| %default
|
|
[ %default
|
|
INTEGER
|
|
|
|
|
REAL
|
|
|
|
|
STRING
|
|
]
|
|
|
|
|
'(' expression ')'
|
|
|
|
|
NOT factor
|
|
;
|
|
|
|
bare_set :
|
|
'{'
|
|
[
|
|
element
|
|
[
|
|
',' element
|
|
]*
|
|
|
|
|
/* empty */
|
|
]
|
|
'}'
|
|
;
|
|
|
|
ActualParameters :
|
|
'(' ExpList? ')'
|
|
;
|
|
|
|
element :
|
|
expression
|
|
[
|
|
UPTO expression
|
|
|
|
|
/* empty */
|
|
]
|
|
;
|
|
|
|
designator :
|
|
qualident designator_tail?
|
|
;
|
|
|
|
designator_tail :
|
|
visible_designator_tail
|
|
[ %persistent
|
|
%default
|
|
selector
|
|
|
|
|
visible_designator_tail
|
|
]*
|
|
;
|
|
|
|
visible_designator_tail :
|
|
'['
|
|
expression
|
|
[
|
|
',' expression
|
|
]*
|
|
']'
|
|
|
|
|
'^'
|
|
;
|