RE: [Haskell] Typeable and Data instances for Double, FiniteMap, ...
| Yes, once you start to use the SYB library you end up wanting it to | cover almost all your types. | I will make an effort *now* hoping that all the instance can still make | it into GHC 6,4. | (There are indeed a few more unsupported types that make obviously sense.) Yes, anything in the HEAD will get into 6.4 Simon ___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
Re: [Haskell] Typeable and Data instances for Double, FiniteMap, ...
Georg Martius wrote: I was playing around with "Scap you Boilerplate" and realised some missing instances of Typeable and Data. Is there a particular reason why there is no Data Double instance? There has been a Double instance under CVS (GHC HEAD) since March 2004. It will be included in GHC 6.4. (BTW, this email should go to glasgow-haskell-users perhaps?) Furthermore I was wondering why no instance for the collection types such as FiniteMap, Set and HashTable is provided. Yes, once you start to use the SYB library you end up wanting it to cover almost all your types. I will make an effort *now* hoping that all the instance can still make it into GHC 6,4. (There are indeed a few more unsupported types that make obviously sense.) I looked at the library source-code (GHC) and reallised that there is really much documenting comments in, but which are not Haddock comments. Again I don't understand that. Is the programmer supposed to look at the source-code rather the API documentation? I wonder how other Haskellers think of that. I tend to use non-Haddock comments whenever I want to document *implementation details*. Is there an idiom for that; so that people get not confused? Regards, Ralf ___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
RE: [Haskell] Typeable and Data instances for Double, FiniteMap, ...
| I was playing around with "Scap you Boilerplate" and realised some missing instances of Typeable and | Data. Is there a particular reason why there is no Data Double instance? | Furthermore I was wondering why no instance for the collection types such as FiniteMap, Set and | HashTable is provided. At the end of the mail [1] there is my implementation of instances for at least | Double and FiniteMap. I've asked Ralf if he'll add them. | Apart from that I looked at the library source-code (GHC) and reallised that there is really much | documenting comments in, but which are not Haddock comments. Again I don't understand that. Is | the programmer supposed to look at the source-code rather the API documentation? It should be Haddock'd. We'd be delighted if anyone was willing to transfer code in comments to Haddock comments, where that is appropriate, and probably add new Haddock comments where necessary. Any volunteers? We'd give CVS access... Simon ___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
[Haskell] Typeable and Data instances for Double, FiniteMap, ...
Hi, I was playing around with "Scap you Boilerplate" and realised some missing instances of Typeable and Data. Is there a particular reason why there is no Data Double instance? Furthermore I was wondering why no instance for the collection types such as FiniteMap, Set and HashTable is provided. At the end of the mail [1] there is my implementation of instances for at least Double and FiniteMap. Apart from that I looked at the library source-code (GHC) and reallised that there is really much documenting comments in, but which are not Haddock comments. Again I don't understand that. Is the programmer supposed to look at the source-code rather the API documentation? Regards, Georg [1] instances: Data Double, Typeable FiniteMap, Data FiniteMap -- -- Data instance for Double. -- IMHO It should be added as a basic type to Data.Constr with DoubleConstr like Float doubleConstr :: Double -> Constr doubleConstr x = mkConstr 1 (show x) Prefix doubleDataType :: DataType doubleDataType = mkDataType [doubleConstr 0.0] instance Data Double where toConstr x = doubleConstr x fromConstr c = read $ conString c dataTypeOf _ = doubleDataType -- -- Typeable instance for FiniteMap fmTc :: TyCon fmTc = mkTyCon "FM" instance (Typeable a, Typeable b) => Typeable (FiniteMap a b) where typeOf fm = mkAppTy fmTc [typeOf ((undefined :: FiniteMap a b -> a) fm)] -- -- Data instance for FiniteMap -- treats the FiniteMap as a list. -- More performant solutions might be possible, -- if internal of FM can be exploited fmConstr :: Constr fmConstr = mkConstr 1 "FM" Prefix fmDataType :: DataType fmDataType = mkDataType [fmConstr] instance (Data a, Data b, Ord a) => Data (FiniteMap a b) where gfoldl f z fm = z listToFM `f` (fmToList fm) toConstr _= fmConstr fromConstr c = case conIndex c of 1 -> emptyFM dataTypeOf _ = fmDataType -- Georg Martius, Tel: (+49 34297) 89434 --- http://www.flexman.homeip.net - ___ Haskell mailing list Haskell@haskell.org http://www.haskell.org/mailman/listinfo/haskell
