rjbs/rx — pull request #1 by dakkar (2012-03-20 14:52:43+00:00)
Title: Interesting values of failure

Hello.

This commit replaces the undef/false values returned by the core checkers with a failure object that:

* overloads to false (all tests still pass)
* has a `->message` method that returns a (hopefully) readable explanation of the failure
* contains the original value
* has some more attributes that may be inspected to diagnose where the failure comes from

Would this be useful? Should I instead release a fork (`Data::Rx::WithExplanation`?)?

By the way, if a user-defined checker returns just a false value, the whole system keeps working, you just don't get any explanation from that checker.