yacc: how to fix ambiguity

Hi,


I am writing a parser for a specific grammar and
found the following problem for which I have no answer:


In my grammar expr and func are defined as:


expr := expr + expr
                | ( expr )
                | IDENTIFIER


func := IDENTIFIER IDENTIFIER ( IDENTIFIER )


define -> DEFINE func expr
                    | DEFINE IDENTIFER expr


The grammar is ambiguous. For instance:


ID ( ID ) + ID yields (a) FUNC expr
                                            (b) ID expr + expr


/*
for instance if I parse "define sign (x) +y" I
would like to mean sign(x) = +y and not sign = (x)+y
*/


I would like to tell yacc to reduce rule (a).


Is-it possible to code it into yacc input?


Any help/advice welcome,


Laurent


--
Laurent Lemaitre
ASTL/Advanced Circuit Research Lab - Europe Tel: +41 22 799 1371
Motorola Semiconductor Products Sector Fax: +41 22 799 1304
Geneva, Switzerland r29173@email.sps.mot.com

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