Daniel Fischer wrote:
Am Samstag 17 Oktober 2009 22:24:08 schrieb Andrew Coppin:
Edward Z. Yang wrote:
Excerpts from Andrew Coppin's message of Sat Oct 17 15:21:28 -0400 2009:
Suppose we have
newtype Foo x
instance Monad Foo
runFoo :: Foo x -> IO x
Are you sure that's really the type you want for runFoo ?
By the definition below, runFoo :: Foo x -> M -> IO x would be the natural type.
M is a type containing a bunch of IORefs. runFoo generates M, feeds M to
Foo x, and then does magical stuff with M afterwards.
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