[antlr-interest] how to resolve ambiguity considering identifiers vs mathematical constants

[Gerard van de Glind]

Hi,

 

I am writing a grammar (using antlr 3) that should be able to parse
identifiers and mathematical constants (they may be used in more complex
constructs). For example, the mathematical constant PI and E. Depending
on the context they can also be identifiers.

How can I best resolve this ambiguity? 

 

Thanks in advance!

 

Gerard

 

 

Here is a simplified grammar: 

 

expression

                :              MATH_CONSTANT | IDENTIFIER;

 

MATH_CONSTANT 

                :              'E' | 'PI';

 

IDENTIFIER 

 :             ('a'..'z'|'A'..'Z')
('0'..'9'|'a'..'z'|'A'..'Z'|'_'|'.')*;

 

 

 

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.antlr.org/pipermail/antlr-interest/attachments/20080527/7ef67585/attachment.html