[antlr-interest] Allowing and maintaining space characters in string literals

[Janet.Hurwitz at usc-bt.com]

Hello- I'm working on a grammar that needs to support embedded blanks in strings: "identifier=two words"
The interpreter keeps breaking at 'two' and doesn't know what to do with 'words'.
I was initially ignoring white space (because 'id1 = oneword, id2 =" two words"' must also be supported with spaces around the = and ,), but obviously, can't do that.
I have tried what was suggested in an archived post:

STRING_LITERAL : (STRCHAR)+ ( ((' ')+ STRCHAR)=> (' ')+ (STRCHAR)+ )*

But that didn't work either! (no viable alternative at input 'words'). It's not including 'words' as part of the string.

In my grammar:
fragment LETTER :('a'..'z' | 'A'..'Z');
fragment DIGIT : '0'..'9';
fragment OTHERCHARS : ('.' | '/' | '-' | '&');
STRCHAR : (LETTER | DIGIT | OTHERCHARS)+;

I have tried various combinations of handling the blank in the lexing v. the parsing, including trying to create a quoted-string rule.
I will have to support the following:

"identifier =two words"
identifier ="two words"

The identifier=value pairs appear in a comma-separated line. There are various nested structures of identifier=value pairs involved, which is why both of the above formats are supported.

*** Bottom line*** I just want to indicate: If a space appears between quotation marks, include it as part of the current token; if not, throw it away.

I have everything working in a complex structure and tree walker except for the embedded blanks allowed in strings! Any suggestions are appreciated.