#! perl use strict; use warnings; use Type::Utils -all; use Type::Library -base, -declare => qw( IncreaseMagnetude ); use Types::Standard qw( Num Str ); use Type::Coercion; my $lookup ={ Ten => 10 }; declare_coercion IncreaseMagnetude, to_type Num, from Str, via{ $lookup->{$_} * 10 }; # Alternate on-the-fly version my $more_magnetude = Type::Coercion->new( name => 'MoreMagnitude', to_type => Num, from => Str, via => sub{ $lookup->{$_}* 11 }, ); print "Using: " . IncreaseMagnetude->display_name . " -> "; print IncreaseMagnetude->( 'Ten' ) . "\n"; print "Using: " . $more_magnetude->display_name . " -> "; print $more_magnetude->( 'Ten' ) . "\n"; #### Using: IncreaseMagnetude -> 100 Using: MoreMagnitude -> 110 #### Using: IncreaseMagnetude -> 100 Using: MoreMagnitude -> Ten