150 lines
1.5 KiB
Text
150 lines
1.5 KiB
Text
/*
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* (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
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* See the copyright notice in the ACK home directory, in the file "Copyright".
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*
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* Author: Ceriel J.H. Jacobs
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*/
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/* E X P R E S S I O N S */
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/* stripped down version of the one in the Modula-2 compiler */
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/* $Id$ */
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qualident :
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IDENT
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[
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selector
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]*
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;
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selector :
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'.' IDENT
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;
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ExpList :
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expression
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[
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',' expression
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]*
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;
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ConstExpression :
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expression
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/*
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* Changed rule in new Modula-2.
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*/
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;
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expression :
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SimpleExpression
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[
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/* relation */
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[ '=' | '#' | '<' | LESSEQUAL | '>' | GREATEREQUAL | IN ]
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SimpleExpression
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/* empty */
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]
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;
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SimpleExpression :
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[
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'+'
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'-'
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/* empty */
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]
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term
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[
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/* AddOperator */
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[ '+' | '-' | OR ] term
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]*
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;
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term :
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factor
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[
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/* MulOperator */
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[ '*' | '/' | DIV | MOD | AND ] factor
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]*
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;
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factor :
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qualident
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[
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designator_tail?
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[
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ActualParameters
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/* empty */
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]
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bare_set
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]
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bare_set
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| %default
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[ %default
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INTEGER
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REAL
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STRING
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]
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'(' expression ')'
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NOT factor
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;
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bare_set :
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'{'
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[
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element
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[
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',' element
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]*
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/* empty */
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]
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'}'
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;
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ActualParameters :
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'(' ExpList? ')'
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;
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element :
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expression
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[
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UPTO expression
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/* empty */
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]
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;
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designator :
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qualident designator_tail?
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;
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designator_tail :
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visible_designator_tail
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[ %persistent
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%default
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selector
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visible_designator_tail
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]*
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;
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visible_designator_tail :
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'['
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expression
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[
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',' expression
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]*
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']'
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'^'
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;
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