[antlr-interest] Parsing advice: predicate needed?

[Rick Schumeyer]

I have a lexer rule

LETTER  :    ('a'..'z')|('A'..'Z');

At a certain point in my parser, I want to know if the next several letters
are the word 'Article'.  I don't want an article token, because that word
can appear at other points, and I don't care.

Can I simply define a parser rule

article_string : 'A' 'r' 't' 'i' 'c' 'l' 'e';

If this works, then I'm really confused because I would think that the lexer
would have already decided that there are several LETTER tokens, so I'm not
sure how the parser would see an 'A' and an 'r', etc.

Or should I use a predicate, something like

my_rule : (do the next several letters spell article)? => LETTER LETTER
LETTER etc.
         | next alternative

If so, then how exactly do I implement "do the next several letters spell
article" ?
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