[antlr-interest] ANTLR not generating correct end condition on greedy=false loop.

[Daniel Shane]

Hi,

Why does this grammar result in an invalid condition to break out of the 
loop:

a: LCURLY any RCURLY;
b: PLUS any MINUS;

any: ( options { greedy=false; } : . )*;

On input

{ fdsfa + fdsfds - fdsfds }

The condition for end of loop is all tokens that can follow any (in this 
case MINUS and RCURLY) even if its quite obvious from the grammar that when 
inside rule a, rule b can never trigger. This of course will give an invalid 
parse because the loop will stop at - and it will expect a RCURLY.

To make this grammar work I have to write:

a: LCURLY ( options { greedy=false; } : . )*  RCURLY;
b: PLUS ( options { greedy=false; } : . )*  MINUS;

so that the end condition is ok. Is there a way to make the above grammar 
work? Is there a good reason for this kind of limitation?

Daniel Shane

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