| dons | ?src concatMap |
| lambdabot | concatMap f = foldr ((++) . f) [] |
| skew | hi dons |
| sioraiocht | ?src Maybe (>>=) |
| lambdabot | (Just x) >>= k = k x Nothing >>= _ = Nothing |
| sioraiocht | ?src IO (>>=) |
| lambdabot | m >>= k = bindIO m k |
| sioraiocht | @type bindIO |
| lambdabot | Not in scope: `bindIO' |
| sorear | JohnMeacham: Are you aware of the GHC Trac? |
| dons | ?users |
| lambdabot | Maximum users seen in #haskell: 340, currently: 282 (82.9%), active: 25 (8.9%) |
| dons | oh, 340 is a new high score. nice. |
| sorear | dons: When will the fusion team be done with nobench? |
| dons | the results got wiped by accident. i'll rerun them during the week, i suppose. after a jhc rebuild. ( i accidentally redirected the fusion results to the wrong file) i'd imagine in the longer term i'll just update the results every few months. or on demand, |
| sorear | How much space do the nobench results take? I'm wondering if it would make sense to do a cron.weekly pull build and run, with indefinite historical results |
| dons | space, not much. its just a matter of writing infrastructure |
| Weremanatee | Haskell books put a lot of emphasis on proving programs. Do haskell programmers do that in practice to any extent? |
| ddarius | Yes for various values of "prove". Though most don't, I would say. However, most use libraries that have that approach applied to them. |
| dons | Weremanatee: semi-formal methods are usually used, related to proof techniques. some automated provers for particular properties are also used. |
| Binkley | I'd imagine the most common proof technique in practice is "it typechecks, so it works" :-) |
| dons | for some commerical and research scenarios, proofs are indeed produced, (e.g. L4 /Haskell kernel, or various galois.com products) |
| ddarius | I was about to say, you can get a lot of "proof power" out of the type system alon. |
| dons | and QC is a semi-formal method too. |
| ddarius | And (ab)using the type system in this manner is pretty common. QC was one of the values of "prove" I was thinking of. |
| Weremanatee | What is QC? |
| dons | Weremanatee: so the general idea of reasoning about programs in terms of proofs is pervasive. |
| ddarius | @where quickcheck |
| lambdabot | http://www.cs.chalmers.se/~rjmh/QuickCheck/ |
| Korollary | QC is about disproving of course, but it's got inductive stuff. |
| ddarius | Other program transformation results get used every day silently by the compiler, e.g. fusion. |
| dons | also though, the process of stating QC properties is similar to stating properties to prove. |