in reply to Custom error messages and moose

Type constraints allow custom error messages. So you could create an "IPAddress" type constraint as a subtype of "Str", and provide an error message for that.

See Moose::Util::TypeConstraints.

perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'

In Section Seekers of Perl Wisdom