http://qs1969.pair.com?node_id=342862


in reply to Why breaking can() is acceptable

I think this discussion is pointless. You either provide an interface to your module---then you decide if it supports can()---or you implement an interface another module expects---then the author of that module decided if can() is needed. That's it.

Implementing a working can() isn't that hard. I'd say this should work (ATTN: untested, WILL contain syntax errors):

sub can { my ($self, $what, $code) = (@_[0,1], undef); return $code if $code = $self->UNIVERSAL::can($what); return $code if $code = $self->_can($what); foreach my $superclass (@ISA) { return $code if $code = eval "\$self->${superclass}::can(\$wha +t)"; } return undef; } sub _can { # aka _load() my ($self, $what) = @_; if ($what eq 'foo') { return sub {'foo'}; } else { return undef; } } sub AUTOLOAD { my ($self, $code) = ($_[0], undef); goto &$code if $code = $self->can($AUTOLOAD); die "oops"; }
PS: This even provides a working way for using AUTOLOAD with multi-inheritance, I'd say.

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