[antlr-interest] Problem w/ string rule

[Anthony Youngman]

Ummm ...

Just a quickie (I've been reading the ANTLR manual :-) and the language
I'm implementing can use ", ', or \ as the string delimiter.

Might it be an idea to have two rules

STRINGDATA : (options {greedy=false;} : (.)* ) ;
STRING : '"' STRINGDATA '"'
       | '\'' STRINGDATA '\''
       | '\\' STRINGDATA '\\'
       ;

And (given that I've been reading the ESC stuff :-) I presume if my
STRINGDATA looked for things like \r or \t, then the "greedy=false" bit
of stringdata would mean that the third option for STRING would eat the
\ before the ESC would see it?

(This is more as info for me and hints to chiplastique than a current
need for a definitive answer - I can always experiment :-)

Cheers,
Wol

-----Original Message-----
From: chiplastique [mailto:jeremyj at imtc.gatech.edu] 
Sent: 19 May 2004 23:18
To: antlr-interest at yahoogroups.com
Subject: [antlr-interest] Problem w/ string rule

I have the following simple lexer rule for identifying strings:

STRING
	:	'"' (~'"')* '"'
	;

This rule should recognize any sequence of characters enclosed by 
double quotes.  However, I've discovered that strings including 
certain punctuation characters such as '\', '`', or ';' cause ANTLR 
to throw a TokenStreamRecognitionException in the STRING rule.

Is this a bug or am I doing something wrong?  I'm using the 2.7.2 
runtime for C#.

Thanks!



 
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