Hi Sjoerd, I don't know the cause of the problem, but if I add this rule, it works: {-# RULES "inline_map" forall g x. map g x = transform (. g) x -#} maybe, for whatever reason, the 'map' is inlined "too late" for the transform/transform rule to see it? Greetings, Daniel On Monday 22 June 2009 11:41:33 Sjoerd Visscher wrote:

Hi all,

I have a rewrite rule as follows:

{-# RULES "transform/transform" forall (f::forall m. Monoid m => (a -> m) -> (b -

...

m))

(g::forall m. Monoid m => (b -> m) -> (c -> m)) (l::FMList c). transform f (transform g l) = transform (g.f) l #-}

It fires on this code:

print $ transform (. (*2)) (transform (. (+1)) (upto 10))

But it doesn't fire on this code:

print $ map (*2) (map (+1) (upto 10)))

with

map g x = transform (. g) x

and with or without {-# INLINE map #-}.

What am I doing wrong?

-- Sjoerd Visscher sjoerd@w3future.com

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