Hi all, Quite often in darcs we want to do a simple loop over a chunk of memory, looking for the first whitespace character or somesuch. Historically this has been done by writing a small snippet of C, but this has a number of downsides (less type safety in the C code, Int/int/HsInt/CInt mismatches, code artificially separated, complicates the Makefiles, have to write C code), so I'd like to replace them with little bits of Haskell. However, it would be easier to convince people that this is the right thing to do if there was no slow-down involved, so I've put some benchmarks together. Hopefully this will help find some cases where ghc is generating poor code, and perhaps help to spot regressions (although it's hard to spot that automatically currently). Essentially each test has n modules, each of which (are supposed to) do the same thing, and it compares certain pairs and it works out how much slower one is than the other on various test sizes. I arbitrarily declared x1.1 to be too slow. The code is at http://urchin.earth.li/~ian/bench/ and the results I get for ghc 6.4.1 are at http://urchin.earth.li/~ian/bench/all.html (interestingly some of the slowdowns I was trying to measure turned out to be speed/ups/). Thanks Ian