Re: [Haskell-cafe] ordNub

2013-10-13 Thread AntC
> Niklas Hambüchen nh2.me> writes: > > > On 14/10/13 03:20, AntC wrote: > > ... > > Then here's a further possible optimisation, instead of making > > separate calls to `member` and `insert`: > > This I understand again. Where do you get insert' from? containers > doesn't seem to have it. Do y

Re: [Haskell-cafe] ordNub

2013-10-13 Thread Niklas Hambüchen
On 14/10/13 03:20, AntC wrote: > Thanks Niklas, I hadn't spotted those benchmarks back in July. No worries :) > I'm surprised at that result for singletons > (and for very small numbers of elements which are in fact each different). I think one of the main reasons for the performance difference

Re: [Haskell-cafe] ordNub

2013-10-13 Thread AntC
> Niklas Hambüchen nh2.me> writes: > > > On 13/10/13 21:42, AntC wrote: > > ... > > If you use the Set library, that fact may be very visible! > > Because Set re-sequences the whole list, as per its Ord instance. > > > > But List.nub preserves the list sequence > > (except for omitting duplicate

Re: [Haskell-cafe] ordNub

2013-10-13 Thread Niklas Hambüchen
On 13/10/13 21:42, AntC wrote: >> Niklas Hambüchen nh2.me> writes: >> >> In sets, the order does not matter, while for nub it does. >> > > Let's be careful here!. Niklas, when you say "order", do you mean: > * the _ordering_ from the Ord instance? Or > * the relative sequence of elements in the l

Re: [Haskell-cafe] ordNub

2013-10-13 Thread AntC
> Niklas Hambüchen nh2.me> writes: > > In sets, the order does not matter, while for nub it does. > Let's be careful here!. Niklas, when you say "order", do you mean: * the _ordering_ from the Ord instance? Or * the relative sequence of elements in the list? > ... the fact that Set is used ins

[Haskell-cafe] Stackage with GHC 7.8 has started

2013-10-13 Thread Michael Snoyman
Hi everyone, I wanted to announce that FP Complete is now running a Jenkins job to build Stackage with GHC 7.8. You can see the current results in the relevant Github issue[1]. Essentially, we're still trying to get version bounds updated so that a build can commence. I'd like to ask two things f

Re: [Haskell-cafe] Nested monadic monoids via Traversable?

2013-10-13 Thread Hans Höglund
If anyone is interested, Typeclassopedia pointed me to Composing Monads by Jones and Duponcheel (1993), which contains exactly my implementation along with some other nice patterns for composing Monads via Traversable.sequence (called swap in the paper) and related operators. It would be interes