antlrgrammartokenizeantlr4lexical-analysis

ANTLR 4 token rule that matches any characters until it encounters XYZ

I want a token rule that gobbles up all characters until it gets to the characters XYZ.

Thus, if the input is this: 

helloXYZ

then the token rule should return this token:

hello

If the input is this:

Blah Blah XYZ

then the token rule should return this token:

Blah Blah

How do I define a token rule to do this?

Solution

  • Using the hint that Terrance gives in his answer, I think this is what Roger is looking for:

    grammar UseLookahead;

parserRule : LexerRule;

LexerRule : .+? { (_input.LA(1) == 'X') &&
                  (_input.LA(2) == 'Y') &&
                  (_input.LA(3) == 'Z') 
                }?
          ;

    This gives the answers required, hello and Blah Blah respectively. I confess that I don't understand the significance of the final ?.