Dynamic Scope for Wrappers

        { my $temporarily = wrap 'myfunc', ...;

          myfunc(...);     # Wrappers are called here
        }
        myfunc(...);       # ... but not here

• If called in scalar or list context, wrap returns a special object:

        return bless sub{ $unwrap=1 }, 'Hook::LexWrap::Cleanup';

• The object is stored in $temporarily

• When $temporarily's lifetime is over, the object is destroyed

        package Hook::LexWrap::Cleanup;

        sub DESTROY { $_[0]->() }

• This sets $unwrap to 1

• The first thing that $imposter does is

                if ($unwrap) { goto &$original }

Next

Copyright © 2003 M. J. Dominus