1.3.8 Functions

function → type identifier ( parameter‑list ? ) compound‑statement
parameter‑list → parameter ( , parameter )*
parameter → type identifier

The ParameterList rule contains a parameter declaration. A parameter declaration is syntactically similar to a variable declaration but lacks the var keyword.

The ParameterList rule is "called" in the Function rule with the function argument.

export module minilang.parser.function;

...

parser FunctionParser
{
    ...
    
    Function(var std::unique_ptr<minilang::ast::FunctionNode> function) : minilang::ast::FunctionNode*
        ::= 
        (
            Type:returnType 
            Identifier:functionName! 
            LPAREN!{ function.reset(new minilang::ast::FunctionNode(returnType, functionName)); } 
            ParameterList(function.get()):params? 
            RPAREN! 
            CompoundStatement:functionBody!{ function->SetBody(functionBody); }
        )
        {
            return function.release();
        }
        ;

    ParameterList(minilang::ast::FunctionNode* function)
        ::= 
        (
            Parameter:left{ function->AddParam(left); } 
            (
                COMMA Parameter:right!{ function->AddParam(right); }
            )*
        )
        ;
        
    ...
}