Higher-Order Parsing

Concatenation

Similarly, the rule

        expression → "(" expression ")"

Translates to:

        $expression = conc(lookfor("("),
                           $expression,
                           lookfor(")"),
                          );

Oops, no, not quite
In better functional languages, this is no problem
Even in Perl, this is fixable—but I don't have time to fix it