Debuggin function RE -> String

[nomeata]

After creating some rather complex regular expression assembly DSL, in the end I get a pattern match failure, and now I am having a hard time to debug my code. It would be great if RE had a show instance, or maybe some debugShow :: Show s => RE s a -> String function that explains the structure of the regular expression.

[ocharles]

I'd love to have this too, but I don't think it's feasible. The fundamental matching primitive in RE is:

    Symbol :: ThreadId -> (s -> Maybe a) -> RE s a

That is, a function mapping tokens to some parsed variation. Thus there's no way to know what the regular expression expects to be able to proceed.

[UnkindPartition]

Related: #36

[UnkindPartition]

In fact, I think I'm going to close this one in favour of #36, as it is a bit more constructive.