Re: [GHC] #9742: The default definitions of foldl1 and foldr1 are too strict

#9742: The default definitions of foldl1 and foldr1 are too strict -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: ekmett Type: bug | Status: patch Priority: normal | Milestone: 7.10.1 Component: Core | Version: 7.9 Libraries | Keywords: Resolution: | Architecture: Unknown/Multiple Operating System: | Difficulty: Easy (less than 1 Unknown/Multiple | hour) Type of failure: Runtime | Blocked By: crash | Related Tickets: Test Case: | Blocking: | Differential Revisions: Phab:D423 | -------------------------------------+------------------------------------- Comment (by Herbert Valerio Riedel ): In [changeset:"6dd218e5f82f19523f9e7aa5371f5bd7beb19663/ghc"]: {{{ #!CommitTicketReference repository="ghc" revision="6dd218e5f82f19523f9e7aa5371f5bd7beb19663" Make Foldable's foldr1 and foldl1 defaults lazier Fixes #9742. Previously, `foldr1` as applied to a list-like structure would be strict in the spine, and `foldl1` would be strict in the spine of a snoc-list. See also https://www.haskell.org/pipermail/libraries/2014-October/024035.html Differential Revision: https://phabricator.haskell.org/D423 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9742#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler