[antlr-interest] Antlr won't backtrack?

[Terence Parr]

On Feb 8, 2009, at 2:48 AM, Vitaliy wrote:
> root                        : statements EOF;
> statements            : (statement)+;
> statement             : label
>                                   | keyword
>                                   | variable
>                                   ;
>
> identifier               : Identifier;
> label                       : identifier COLON;
> keyword                : KEYWORD (identifier)?;
> variable                 : identifier;


"keyword label:" will always match rule keyword and then fail.  ANTLR  
will match greedily because you told it to shut up and backtrack.   
It's hiding the warning that identifier can match now or later (during  
statements loop).

Ter
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