Ashley Yakeley wrote:
At 2002-11-22 08:12, Lu Mudong wrote:
what i need is a string,
You can do the conversion with "<-", but only inside a "do" block. For
instance:
myReadFile :: IO String
myReadFile = ...
main = do
s <- myReadFile
putStrLn s
Here, s has type String.
'do' is a syntactic sugar of monadic operations.
The original form can be written as
main = myReadFile >>= \s -> putStrLn s
and more short by eta-conversion
main = myReadFile >>= putStrLn
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