[Haskell-cafe] Spot the difference!
prstanley at ntlworld.com
Thu Sep 20 01:30:06 EDT 2007
> test1 n _ = 1 + n
> test2 n = \_ -> 1 + n
>I don't know if it's still the case, but GHC used to compile different
>code for these at high optimisation levels. The first was essentially
> test1 = \n _ -> 1+n
>And the second to:
> test2 = \n -> let x = n+1 in \_ -> x
>The difference is that test1 is faster if it's usually fully applied,
>test2 is fully lazy.
Fully lazy? Can you elaborate please?
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