Can HLint help spot space leaks? (was: Re: [Haskell-cafe]
Generating Haskell with associated types (and kind annotations))
ndmitchell at gmail.com
Sat May 9 05:08:13 EDT 2009
> Hi Neil,
> A bit off-topic, but your post reminded me: Does HLint currently help the
> user find space leaks? For example, does it recommend strict folds instead
> of lazy folds? I looked at the FAQ but this was not listed. I don't really
> know how feasible this is.
It spots when you use replicateM or mapM, but don't use the result,
and should have actually used the _ versions.
It doesn't spot foldl s that should be foldl' s - in general you only
know that if you have the strictness information, which HLint doesn't.
You could add the rule foldl ==> foldl', but it's not in general
correct, so it won't be added to the default rule set.
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