Question

I am writing a compiler with Yacc and having trouble figuring out how to write productions to match a function. In my language, functions are defined like this:

function foo(a, b, c);

I created lex patterns to match the word function to FUNC, and any C style name to NAME.

Ideally, I would want something like this:

FUNC NAME OBRACKET NAME (COMMA NAME)* CBRACKET

Which would allow some unknown number of pairs of COMMA NAME in between NAME and CBRACKET.

Additionally, how would I know how many it found?

Answer 1

After a little experimentation, I found this to work quite well:

int argCount;
int args[128];

arglist: nonemptyarglist
       |
        ;

nonemptyarglist: nonemptyarglist COMMA singleArgList
               | singleArgList
        {

        };

singleArgList:
            REGISTER
        {
            args[argCount++] = $1;
        };