7 Feb
2009
7 Feb
'09
7:25 p.m.
On Mon, 12 Jan 2009, Duncan Coutts wrote:
On Mon, 2009-01-12 at 15:06 +0100, Henning Thielemann wrote:
It has to be manually transformed into a version that is not recursive at the top level:
map :: (a -> b) -> [a] -> [b] map f = go where go [] = [] go (x:xs) = f x : go xs
Then the map can be inlined at the call site and the 'f' inlined into the body of 'go'.
Maybe HLint can make such suggestions ...
I think HLint's philosophy prefers elegant code to performance hacks.
I encountered just another instance of 'jumping into the wrong loop' when experimenting with a function using top-level recursion. Thus I summarized the stylistic reasons pro local recursion: http://www.haskell.org/haskellwiki/Top-level_vs._local_recursion