#2439: Missed optimisation with dictionaries and loops -------------------------------------+------------------------------------- Reporter: rl | Owner: simonpj Type: bug | Status: new Priority: lowest | Milestone: 7.12.1 Component: Compiler | Version: 6.9 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Runtime | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by simonpj): You don't give an actual example, and my brain is too small to reconstruct the code you have in mind. Still, I do agree that wrapping a single value in a data type carries an indirection cost. We could make GHC strict in non-single-method dictionaries; indeed that's the way it's supposed to work right now. But someone needs to actually try it out, benchmark etc. In short, I'm in no hurry to make this change. Meanwhile, it's a crime that you have to fake this stuff up. The more concrete your examples of what you can't do type-securely, the more likely someone is to fix them. At the moment I am clueless. Simon -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/2439#comment:24 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler