#15521: Provide a strict version of sum -------------------------------------+------------------------------------- Reporter: dnadales | Owner: (none) Type: feature request | Status: new Priority: normal | Milestone: 8.6.1 Component: Prelude | Version: 8.4.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by svenpanne): Be careful, you're mixing things up here, because there are actually 3 different `sum`s: * In `Prelude`: This must behave like the definition on p. 121 from the report mentioned above. * In `Data.List`: The report doesn't state anything regarding strictness, but following the principle of least surprise, this should better behave like `Prelude.sum`. Note that GHC 7.10 (i.e. `base` 4.8) generalized the signature a bit. * In `Data.Foldable`: Basically the same holds here as for the previous item. Note that I'm not saying that the current strictness behavior of `sum` is a brilliant idea, but it's basically far too late to change this. Doing such a change would definitely wreak havoc in the package ecosystem, because it is not even reflected by a change in the signature. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15521#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler