From:	GBeushausen AT t-online DOT de (Gunnar Beushausen)
Newsgroups:	comp.os.msdos.djgpp
Subject:	Bison optionality
Date:	8 Feb 1997 03:05:33 GMT
Organization:	Telekom Online Internet Gateway
Lines:	18
Message-ID:	<5dgqht$nu3@news00.btx.dtag.de>
Mime-Version:	1.0
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

Hi there!

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();}

But when i execute the code i can't leave out the last expression,
otherwise there would be a parse error. 

Can somebody help me please?

---
Gunnar Beushausen
GBeushausen AT t-online DOT de
http://www.hof.de/~gbasic

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