I disagree -- see below Dan Weston wrote:
I suggest that it be removed and the real Control.Monad.Fix.fix function be defined in its own section, with an side-by-side comparison with a named recursive function. This would be useful because the type
fix :: (a -> a) -> a
is highly confusing, suggesting to newcomers a usage like:
f = fix (+1)
which is undefined (and seems to be "missing an argument"), when invariably its type is in practice restricted to:
fix :: ((a -> b) -> (a -> b)) -> (a -> b)
which is much more suggestive (but nowhere to be found in the docs).
Dan Weston
Useful counterexample: -- import Data.Function(fix) fix :: (t -> t) -> t fix f = let f' = f f' in f' one :: [Int] -> [Int] one = (1:) ones = [Int] ones = fix one This emphasizes that Haskell's fix can define non-function types, which the Y combinator in strict languages is not useful for. (Unless someone would like to correct me...) -- Chris