[antlr-interest] How does one handle variable number of function parameters?

[Rob Greene]

> A function call sounds like it looks something like this:
>
>    function_call : ID LPAREN^ args RPAREN!;
>    args  :  expr ( COMMA! expr )* { ## = #( #[ARGLIST,"ARGLIST"], ## ); } ;
>
> Is this the place you need help, or is it something after this? Once
> you have it parsed, where do you need to go?

Yes, I think this is where I need help. I've currently got the
function defined as this (identifier piece, of course):

term
	: NUMBER
	| LPAREN! expression RPAREN!
	| IDENTIFIER^ ( LPAREN! expression (COMMA! expression)* RPAREN! )?
	;

I see:
1) You've made the LPAREN the root - why? I figured I'd have the
IDENTIFIER as the root with the expressions as the children. Probaby
doesn't matter if I get the tree parser setup right...?

2) What the heck does this mean? I've seen it mentioned in the ANTLR
documentation, but I didn't grok it.
    args  :  expr ( COMMA! expr )* { ## = #( #[ARGLIST,"ARGLIST"], ## ); } ;

3) I'd like to have the parenthesis optional. Do I want to have two
definitions to pick up the parenthesis in the parser grammar file?
	| (IDENTIFIER LPARN) => IDENTIFIER^ LPAREN! expression (COMMA!
expression)* RPAREN!
	| IDENTIFIER^

4) and, finally, I need to figure out how to "process" this. With my
expression parser, I'm basically doing an interpreter, so that seems
to make everything a lot simpler. All the other functions are working
(you'll see it at the bottom of the expression.g file.

I've re-attached my current grammar and hacking file just in case that
helps. Note that I think the Main class will hold the function
arguments as they get evaluated and then they will be available for
the function call itself.

Thanks again! This is really neat - but I keep on missing important tidbits. :-(
-Rob
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