[beautiful quote marks, thank you] | > Can you give some examples to back up this claim? I am skeptical | | I can look into it again after ICFP. | | I did spend some time trying to tease apart the performance | improvements we got from inlining foldl'. From what I remember, the | biggest gain from inlining is that the higher-order argument is known, Ah yes! But that is *quite different* from specialising only on the *type*! | foldl' :: (a -> b -> a) -> a -> [b] -> a | foldl' = ... | {-# SPECIALIZABLE foldl' #-} | | and then have foldl' be specialized in the client module at whatever | type it's called at, but only once for each type (instead of once per | call site). For overloaded functions, that is precisely what I'm proposing. For foldl' I think you will get no benefit from specialising on the type; only from specialising on the actual function passed. So in that case inlining probably really is the answer. Simon