If I have this right, Stream is a monad transformer.
Stream s m t means that it parses 's', is stacked with monad 'm' and has a result of type 't'

So Identity is a monad, the simplest monad, defined as such:

newtype Indentity t = Identity { runIdentity :: t }

It's the identity monad, that does nothing special but wrapping its result.

2011/10/8 Captain Freako <capn.freako@gmail.com>

Hi all,

In this definition from the Parsec library:
parse :: (Stream s Identity t)
      => Parsec s () a -> SourceName -> s -> Either ParseError a
parse p = runP p ()
what's the significance of `Identity t'?
(`t' isn't used anywhere.)

Thanks,
-db

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