[antlr-interest] simple novice grammar question

[Greg Gimler]

I'm trying to define a simple parser which constructs a series of boolean 
conditions.  Basically, just like a Java or C boolean condition.

So the string "( (x=='somestring') && (y>3 || z>4) )"  would be accepted by 
this language.  Likewise,
Strings: "( (x>3) (y>2) )",   "()",  "x>3 y=='somestring'" ,and " (x>3 
y=='somestring')" should all fail.

I looked at some of the sample GNU C and Java grammars for this section but 
it proved to be a little above my understanding of the antlr syntax.  Right 
now, my parser works for most strings but lets
"(x>3)(y=='somestring')"  pass as a valid string when I would like it to 
fail.

I've attached just the parser below (if seeing my lexer helps, let me know).


// parser rules
startRule
    : filter
    ;

filter
    : LPAREN^ bool_or RPAREN!
    ;

bool_or
    : bool_and (OR^ bool_and)*
    ;

bool_and
    : bool_comp_seq (AND^ bool_comp_seq)*
    ;

bool_comp_seq
    : bool_comp
    ;

bool_comp
    : factor ((EQ^|NEQ^|LT^|LTE^|GT^|GTE^) factor)*
    ;

factor
    : LPAREN^ bool_or RPAREN!
    | IDENTIFIER
    | (NUMBER|STRING)
    ;

If anyone could provide some assistance getting this fixed I would 
appreciate it.  Whenever I've tried, I end up with warnings that I don't 
know how to remedy.  Perhaps there's a better way of defining what I already 
have?  Thanks.


                                                      -Greg





 
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