Message-ID:	<32FE037C.839@pobox.oleane.com>
Date:	Sun, 09 Feb 1997 18:03:56 +0100
From:	Francois Charton <deef AT pobox DOT oleane DOT com>
Organization:	CCMSA
MIME-Version:	1.0
To:	Gunnar Beushausen <GBeushausen AT t-online DOT de>
CC:	djgpp AT delorie DOT com
Subject:	Re: Bison optionality
References:	<5dgqht$nu3 AT news00 DOT btx DOT dtag DOT de>

Gunnar Beushausen wrote:
> Does anyone know how to implement optionality into a bison script?
> I'm creating a command that's called "circle" with the arguments
> x_position, y_position, radius and color. But i want color to be an
> optional argumend. My current code looks like this
> 
> | circle expression expression expression expression {circle();}
> 

Try:
| circle expression expression expression {circle();}
| circle expression expression expression expression {circle();}

Bison will warn you about shift/reduce conflicts, but it does not matter.

Francois

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