[antlr-interest] A Question on FAQ

[Gokulakannan Somasundaram]

Hi,
   I was going through the FAQ "How can I allow keywords as identifiers?".
The example is like this

*grammar Pred;

prog: stat+ ;

stat: keyIF expr stat
   | keyCALL ID ';'
   | ';'
   ;

expr: ID
   ;

keyIF : {input.LT(1).getText().equals("if")}? ID ;

keyCALL : {input.LT(1).getText().equals("call")}? ID ;

ID : 'a'..'z'+ ;
WS : (' '|'\n')+ {$channel=HIDDEN;} ;

*
My doubt is, why can't we write KeyIF and KeyCall as

KEYIF : 'if';

KEYCALL : 'call';

instead of writing like the above one. Or am i just repeating what is
already told in the second alternative in the same FAQ?

Thanks,
Gokul.
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