It looks like right now the default error message on a pattern uses the pattern name (key), but it would be nice to have a separate error message for a couple of reasons:
I could write a custom validator for this, but even the built in patterns I'd have to either write custom validators for or change the message to a generic "Field is not in correct format" or something like that.
I could write an extended pattern validator to do what I need too, but it seems like it might be functionality that other people would want.
Other than that, I love the library!
+1, I was about to log a request for allowing custom messages to be created for patterns.
Added ability to set error message per pattern. Closes #174