I have not thought too deeply on Monads in Perl but my impression is that you can only borrow some ideas and get an approximation to what Monads are in e.g. Haskell (the only programing language where they play a really prominent part).

The reason for this is that Perl lacks the proper type-system, so you cannot properly type e.g. the "bind"-operator and so every attempt to implement something like Monads just end up using (basically untyped) subs and so you loose all the benefits of compile-time type-checking.

Or what do you think?