So I keep hearing (from various AI professors) how great lisp is. They're probably right. One of the big things is macros: how they allow you generate new code on the fly. While writing some nice, old-fashioned perl code, I noticed myself making a bunch of nearly-identical functions to set and retrieve values in my object, and thought "Wow! What we need here is macros!" So here's my take on it. My main question is whether there's a better way than using evals to do this; the second question is what's the better way in general to do this? 

sub _setter_getter_maker
{
  my $subname = shift;
  my $funcref;

  $funcref = eval<<"END";
  sub
  {
    my(\$self, \$$subname) = \@_;
    \$self->{'$subname'} = \$$subname if defined \$$subname;
    return \$self->{'$subname'};
  };
END

  return $funcref;
}

[download]

The idea for use is basically thus: 

my $pretend_object = {};
my $new_func = _setter_getter_maker($pretend_object, 'attrib');

#Now we can set a value for 'attrib' in this object
$new_func->('value');

[download]

In reply to Pretending to be lisp: macros by anjiro

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