[GHC] #3709: Data.Either.partitionEithers is not lazy enough
lemming at henning-thielemann.de
Thu Dec 3 09:12:24 EST 2009
On Thu, 3 Dec 2009, Malcolm Wallace wrote:
>> #3709: Data.Either.partitionEithers is not lazy enough
>> This is a behavioural change, e.g.:
>> Main> case partitionEithers1 [Left 'a', error "Not me"] of (x : _, _) -> x
>> Program error: Not me
>> Main> case partitionEithers2 [Left 'a', error "Not me"] of (x : _, _) -> x
> Yes, and isn't that the point of the bugfix? No non-bottoming program has
> changed, but fewer programs fail now. I find it hard to imagine that anyone
> could have been relying on getting a crash here.
Making something more lazy can cause a memory leak.
More information about the Libraries