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>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

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