Building an Interpreter

Why write a parser and an interpreter?

We already have one.

In Perl:

x.E => sub { my $x = shift; E }

(E F) => $E->($F)

For example:

        # TRUE = pq.p
        $TRUE = sub { my $p = shift;
                      sub { my $q = shift; 
                            $p
                          };
                    };

We can use this to try out the abstract stuff from the previous slides