Antlr: ignore keywords in specific context

Question

I'm constructing an English-like domain specific language with ANTLR. Its keywords are context-sensitive. (I know it sounds dirty, but it makes a lot of sense for the non-programmer target users.) For example, the usual logical operators such as or and not are to be treated as identifiers when surrounded in brackets, [like this and this]. My current approach looks like this:

bracketedStatement
    : '[' bracketedWord+ ']'
    ;

bracketedWord
    :   (~(']')+
    ;

This, when combined with lexical definitions such as the following:

AND: 'and' ;
OR: 'or' ;

Produces the warning"Decision can match input such as "{AND..PROCESS, RPAREN..'with'}" using multiple alternatives: 1, 2". I'm clearly creating ambiguity for ANTLR, but I don't know how to resolve it. How do I fix this?

Could you show a more complete example? In ANTLR, the order of the rules is important, and may lead to ambiguity. — Apalala, Oct 18 '13 at 04:56
`~(']')` inside a parser rule does not do what you think it does. See: http://stackoverflow.com/questions/8284919/negating-inside-lexer-and-parser-rules — Bart Kiers, Oct 18 '13 at 05:41
Possible duplicate of [Negating inside lexer- and parser rules](https://stackoverflow.com/questions/8284919/negating-inside-lexer-and-parser-rules) — Mark Rotteveel, Dec 01 '18 at 13:57

score 0 · Accepted Answer · edited May 23 '17 at 12:10

0

For anyone who finds this, check out this stack overflow question. It clarifies how to use the negation symbol correctly.

edited May 23 '17 at 12:10

Community

1
1

answered Oct 22 '13 at 17:08

Dylan Knowles

2,726
1
26
52

Antlr: ignore keywords in specific context

1 Answers1