If you have a type error message at the very start of a do statement, the result
can be rather confusing, because the typechecker doesn't know that do's are
almost always have type (IO (something)) and so tries to shoehorn the monad
to fit the type. This has actually happened to me several
| -Original Message-
| From: George Russell [mailto:[EMAIL PROTECTED]]
| Sent: 16 July 2001 15:56
| To: [EMAIL PROTECTED]
| Subject: do's and error messages
|
|
| If you have a type error message at the very start of a do
| statement, the result can be rather confusing, because
On 2001-07-16T09:48:46-0700, Simon Peyton-Jones wrote:
Here's an example:
f x = do { c ; putStrLn x; return () }
Would
asIO :: IO a - IO a
asIO = id
help here?
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