It was ready to merge 3 months ago... but perhaps just got lost in the press of events. liyang said then " Since this issue affects a large number of users and doesn't seem too contentious, could this fix be included in 7.6.2?" But we are where we are. I honestly don't know if it's worth the risk, though it seems very slight, and certainly only affects 'deriving Foldable/Traversable". Simon | -----Original Message----- | From: Ian Lynagh [mailto:ian@well-typed.com] | Sent: 17 April 2013 14:54 | To: Simon Peyton-Jones; ghc-devs@haskell.org | Subject: Re: [GHC] #7436: Derived Foldable and Traversable instances become | extremely inefficient due to eta-expansion | | | Hi Simon, | | On Tue, Apr 16, 2013 at 03:55:16PM -0000, GHC wrote: | > #7436: Derived Foldable and Traversable instances become extremely | inefficient due | > to eta-expansion | > | > Comment(by simonpj): | > | > This one is fixed, just awaiting merging into 7.6.3 | | My suggestion was that we only fix #7748 in 7.6.3, as that seems to be a | show-stopper. There are several other fixes that we would ordinarily | merge into 7.6.3, but every change has a risk of causing a regression | (after all, 7.6.2 made #7748 worse), and we want to get 7.6.3 out as | quickly as possible (so as not to hold up the HP release) so we don't | have the luxury of being able to have a long testing/RC phase. | | But if you think it's important enough, and the fix safe enough, please | let me know and I'll merge it. | | | Thanks | Ian