[antlr-interest] just added $FIRST(rule) and $FOLLOW(rule)

Terence Parr parrt at jguru.com
Sat Sep 14 23:02:55 PDT 2002


Extending Ric's work, I have made $FIRST and $FOLLOW computations 
available to actions and exception actions.  If you omit the arg it 
assumes current rule.  Note that this returns the name of a bitset you 
can use to test or pass to consumeUntil().

a : A {$FIRST(a); $FIRST} B
     catch [MyExc e] {
         foo = $FOLLOW(a);

You can use for a variety of things:

if ( $FIRST(a).member(LBRACK) ) {...}

PS	Ric, note that I've moved the computation into the two action.g 
files (moving from code generators; cleaner).
Co-founder, http://www.jguru.com
Creator, ANTLR Parser Generator: http://www.antlr.org


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