Ticket: http://hackage.haskell.org/trac/ghc/ticket/4280 Proposal: Performance improvements for Data.Set Following on from ticket #4277 here is a similar patch for Data.Set. This proposal provides a patch that improves performance for many parts of the API. Three standard techniques are applied to the code: * Worker/Wrapper transformations of recursive functions with constant arguments (aka. the static argument transformation). * Explicit inlining of wrapper functions. * Explicit strictness of keys to functions. Three complementary, but orthogonal patches are provided. * Add a testsuite, with coverage data (currently 51% of top level functions, and all core functions). * Add a micro-benchmark suite based on Criterion, for empirical evidence of improvements to each function. * The optimization patch itself. All 3 patches should be applied, under this proposal. The benchmark results are relatively clear: 32% faster on OS X 10.5.8 on 2 GHz Core 2 Duo The consideration period is 3 weeks (before ICFP). Work carried out over 28/29th August, 2010 in Utrecht, NL, by Johan Tibell and Don Stewart.