#9345: Data.List.inits is extremely slow -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: Type: bug | Status: new Priority: high | Milestone: 7.8.4 Component: | Version: 7.8.3 libraries/base | Keywords: Resolution: | Architecture: Unknown/Multiple Operating System: | Difficulty: Easy (less than 1 Unknown/Multiple | hour) Type of failure: Runtime | Blocked By: performance bug | Related Tickets: Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by nomeata): Didn’t look at the core yet, but this might be a case of non-linear recursion where an arity analysis in insufficient to get good code for a left fold, see 5.1.1 in http://pp.ipd.kit.edu/uploads/publikationen/breitner14callarity.pdf. I can have a closer look later. Can you, with these examples, please always include one complete self-contained file? Otherwise there is a risk that I might be testing with the wrong version of inits/scanl'/whatever. I assume you are on GHC HEAD? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9345#comment:22 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler