convertible (empty) → 1.0.0
raw patch · 11 files changed
+1766/−0 lines, 11 filesdep +HUnitdep +QuickCheckdep +basesetup-changed
Dependencies added: HUnit, QuickCheck, base, bytestring, containers, mtl, old-locale, old-time, testpack, time
Files
- COPYING +510/−0
- COPYRIGHT +18/−0
- Data/Convertible.hs +40/−0
- Data/Convertible/Base.hs +113/−0
- Data/Convertible/Instances.hs +36/−0
- Data/Convertible/Instances/Map.hs +30/−0
- Data/Convertible/Instances/Num.hs +671/−0
- Data/Convertible/Instances/Time.hs +212/−0
- Data/Convertible/Utils.hs +52/−0
- Setup.lhs +6/−0
- convertible.cabal +78/−0
+ COPYING view
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+ COPYRIGHT view
@@ -0,0 +1,18 @@+Copyright (C) 2009 John Goerzen <jgoerzen@complete.org>++ This library is free software; you can redistribute it and/or+ modify it under the terms of the GNU Lesser General Public+ License as published by the Free Software Foundation; either+ version 2.1 of the License, or (at your option) any later version.++ This library is distributed in the hope that it will be useful,+ but WITHOUT ANY WARRANTY; without even the implied warranty of+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU+ Lesser General Public License for more details.++ You should have received a copy of the GNU Lesser General Public+ License along with this library; if not, write to the Free Software+ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA++Please see COPYING for the license.+
+ Data/Convertible.hs view
@@ -0,0 +1,40 @@+{-+Copyright (C) 2009 John Goerzen <jgoerzen@complete.org>++All rights reserved.++For license and copyright information, see the file COPYRIGHT++-}++{- |+ Module : Data.Convertible.Base+ Copyright : Copyright (C) 2009 John Goerzen+ License : LGPL++ Maintainer : John Goerzen <jgoerzen@complete.org>+ Stability : provisional+ Portability: portable++This is a library to provide a uniform interface for safe conversions between+different types of data. To get started reading about it, consult:++"Data.Convertible.Base" for information about the conversions themselves++"Data.Convertible.Utils" for helpful tools for people writing 'Convertible' instances++"Data.Convertible.Instances" for a large collection of ready-built 'Convertible' instances++You can import these modules individually, or this module will export the entire library+for you.+-}++module Data.Convertible (+ module Data.Convertible.Base,+ module Data.Convertible.Utils,+ module Data.Convertible.Instances+ )+where+import Data.Convertible.Base+import Data.Convertible.Utils+import Data.Convertible.Instances
+ Data/Convertible/Base.hs view
@@ -0,0 +1,113 @@+{-+Copyright (C) 2009 John Goerzen <jgoerzen@complete.org>++All rights reserved.++For license and copyright information, see the file COPYRIGHT++-}++{- |+ Module : Data.Convertible.Base+ Copyright : Copyright (C) 2009 John Goerzen+ License : LGPL++ Maintainer : John Goerzen <jgoerzen@complete.org>+ Stability : provisional+ Portability: portable++-}++module Data.Convertible.Base( -- * The conversion process+ convert,+ Convertible(..),+ -- * Handling the results+ ConvertResult,+ ConvertError(..),+ convError,+ prettyConvertError+ )+where+import Control.Monad.Error+import Data.Typeable++{- | The result of a safe conversion via 'safeConvert'. -}+type ConvertResult a = Either ConvertError a++----------------------------------------------------------------------+-- Conversions+----------------------------------------------------------------------++{- | A typeclass that represents something that can be converted.+A @Convertible a b@ instance represents an @a@ that can be converted to a @b@. -}+class Convertible a b where+ {- | Convert @a@ to @b@, returning Right on success and Left on error.+ For a simpler interface, see 'convert'. -}+ safeConvert :: a -> ConvertResult b++{-+{- | Any type can be converted to itself. -}+instance Convertible a a where+ safeConvert x = return x+-}++{-+{- | Lists of any convertible type can be converted. -}+instance Convertible a b => Convertible [a] [b] where+ safeConvert = mapM safeConvert+-}++{- | Convert from one type of data to another. Raises an exception if there is+an error with the conversion. For a function that does not raise an exception+in that case, see 'safeConvert'. -}+convert :: Convertible a b => a -> b+convert x = + case safeConvert x of+ Left e -> error (prettyConvertError e)+ Right r -> r++{-+instance Convertible Int Double where+ safeConvert = return . fromIntegral+instance Convertible Double Int where+ safeConvert = return . truncate -- could do bounds checking here+instance Convertible Integer Double where+ safeConvert = return . fromIntegral+instance Convertible Double Integer where+ safeConvert = return . truncate+-}++----------------------------------------------------------------------+-- Error Handling+----------------------------------------------------------------------++{- | How we indicate that there was an error. -}+data ConvertError = ConvertError {+ convSourceValue :: String,+ convSourceType :: String,+ convDestType :: String,+ convErrorMessage :: String}+ deriving (Eq, Read, Show)++instance Error ConvertError where+ strMsg x = ConvertError "(unknown)" "(unknown)" "(unknown)" x++convError' :: (Show a, Typeable a, Typeable b) =>+ String -> a -> b -> ConvertResult b+convError' msg inpval retval = + Left $ ConvertError {+ convSourceValue = show inpval,+ convSourceType = show . typeOf $ inpval,+ convDestType = show . typeOf $ retval,+ convErrorMessage = msg}+ +convError :: (Show a, Typeable a, Typeable b) =>+ String -> a -> ConvertResult b+convError msg inpval = + convError' msg inpval undefined+ +prettyConvertError :: ConvertError -> String+prettyConvertError (ConvertError sv st dt em) =+ "Convertible: error converting source data " ++ sv ++ " of type " ++ st+ ++ " to type " ++ dt ++ ": " ++ em+
+ Data/Convertible/Instances.hs view
@@ -0,0 +1,36 @@+{-+Copyright (C) 2009 John Goerzen <jgoerzen@complete.org>++All rights reserved.++For license and copyright information, see the file COPYRIGHT++-}++{- |+ Module : Data.Convertible.Instances+ Copyright : Copyright (C) 2009 John Goerzen+ License : LGPL++ Maintainer : John Goerzen <jgoerzen@complete.org>+ Stability : provisional+ Portability: portable++Collection of ready-made 'Data.Convertible.Convertible' instances. See+each individual module for more docs:++"Data.Convertible.Instances.Map"++"Data.Convertible.Instances.Num"++"Data.Convertible.Instances.Time"++You can find a list of these instances at 'Data.Convertible.Base.Convertible'.+-}++module Data.Convertible.Instances(+ ) where++import Data.Convertible.Instances.Map()+import Data.Convertible.Instances.Num()+import Data.Convertible.Instances.Time()
+ Data/Convertible/Instances/Map.hs view
@@ -0,0 +1,30 @@+{- |+ Module : Data.Convertible.Instances.Map+ Copyright : Copyright (C) 2009 John Goerzen+ License : LGPL++ Maintainer : John Goerzen <jgoerzen@complete.org>+ Stability : provisional+ Portability: portable++Instances to convert between Map and association list.++Copyright (C) 2009 John Goerzen <jgoerzen@complete.org>++All rights reserved.++For license and copyright information, see the file COPYRIGHT++-}++module Data.Convertible.Instances.Map()+where++import Data.Convertible.Base++import qualified Data.Map as Map++instance Ord k => Convertible [(k, a)] (Map.Map k a) where+ safeConvert = return . Map.fromList+instance Convertible (Map.Map k a) [(k, a)] where+ safeConvert = return . Map.toList
+ Data/Convertible/Instances/Num.hs view
@@ -0,0 +1,671 @@+{- |+ Module : Data.Convertible.Instances.Num+ Copyright : Copyright (C) 2009 John Goerzen+ License : LGPL++ Maintainer : John Goerzen <jgoerzen@complete.org>+ Stability : provisional+ Portability: portable++Numeric instances for Convertible.++Copyright (C) 2009 John Goerzen <jgoerzen@complete.org>++All rights reserved.++For license and copyright information, see the file COPYRIGHT++These instances perform conversion between numeric types such as Double, Int, Integer,+Rational, and the like. Here are some notes about the conversion process:++Conversions from floating-point types such as Double to integral types are dune via the+'truncate' function. This is a somewhat arbitrary decision; if you need different+behavior, you will have to write your own instance or manually perform the conversion.++All conversions perform bounds checking. If a value is too large for its destination+type, you will get a 'ConvertError' informing you of this. Note that this behavior+differs from functions in the Haskell standard libraries, which will perform the+conversion without error, but give you garbage in the end.++Conversions do not perform precision checking; loss of precision is implied with certain+conversions (for instance, Double to Float) and this is not an error.+-}++module Data.Convertible.Instances.Num()+where++import Data.Convertible.Base+import Data.Convertible.Utils+import Data.Int+import Data.Word++------------------------------------------------------------++{- The following instances generated by this code:++fp = ["Double", "Float", "Rational"]+int = ["Int", "Int8", "Int16", "Int32", "Int64", "Word", "Word8", "Word16", "Word32",+ "Word64"]+allItems l1 l2 = concatMap (\x -> map (\y -> (x, y)) int) fp+work = allItems fp int+printIt (f, i) = + "instance Convertible " ++ f ++ " " ++ i ++ " where \n\+ \ safeConvert = boundedConversion (return . truncate)\n\+ \instance Convertible " ++ i ++ " " ++ f ++ " where \n\+ \ safeConvert = return . fromIntegral\n"++main = mapM_ (putStrLn . printIt) work+-}++instance Convertible Double Int where + safeConvert = boundedConversion (return . truncate)+instance Convertible Int Double where + safeConvert = return . fromIntegral++instance Convertible Double Int8 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Int8 Double where + safeConvert = return . fromIntegral++instance Convertible Double Int16 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Int16 Double where + safeConvert = return . fromIntegral++instance Convertible Double Int32 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Int32 Double where + safeConvert = return . fromIntegral++instance Convertible Double Int64 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Int64 Double where + safeConvert = return . fromIntegral++instance Convertible Double Word where + safeConvert = boundedConversion (return . truncate)+instance Convertible Word Double where + safeConvert = return . fromIntegral++instance Convertible Double Word8 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Word8 Double where + safeConvert = return . fromIntegral++instance Convertible Double Word16 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Word16 Double where + safeConvert = return . fromIntegral++instance Convertible Double Word32 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Word32 Double where + safeConvert = return . fromIntegral++instance Convertible Double Word64 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Word64 Double where + safeConvert = return . fromIntegral++instance Convertible Float Int where + safeConvert = boundedConversion (return . truncate)+instance Convertible Int Float where + safeConvert = return . fromIntegral++instance Convertible Float Int8 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Int8 Float where + safeConvert = return . fromIntegral++instance Convertible Float Int16 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Int16 Float where + safeConvert = return . fromIntegral++instance Convertible Float Int32 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Int32 Float where + safeConvert = return . fromIntegral++instance Convertible Float Int64 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Int64 Float where + safeConvert = return . fromIntegral++instance Convertible Float Word where + safeConvert = boundedConversion (return . truncate)+instance Convertible Word Float where + safeConvert = return . fromIntegral++instance Convertible Float Word8 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Word8 Float where + safeConvert = return . fromIntegral++instance Convertible Float Word16 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Word16 Float where + safeConvert = return . fromIntegral++instance Convertible Float Word32 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Word32 Float where + safeConvert = return . fromIntegral++instance Convertible Float Word64 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Word64 Float where + safeConvert = return . fromIntegral++instance Convertible Rational Int where + safeConvert = boundedConversion (return . truncate)+instance Convertible Int Rational where + safeConvert = return . fromIntegral++instance Convertible Rational Int8 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Int8 Rational where + safeConvert = return . fromIntegral++instance Convertible Rational Int16 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Int16 Rational where + safeConvert = return . fromIntegral++instance Convertible Rational Int32 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Int32 Rational where + safeConvert = return . fromIntegral++instance Convertible Rational Int64 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Int64 Rational where + safeConvert = return . fromIntegral++instance Convertible Rational Word where + safeConvert = boundedConversion (return . truncate)+instance Convertible Word Rational where + safeConvert = return . fromIntegral++instance Convertible Rational Word8 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Word8 Rational where + safeConvert = return . fromIntegral++instance Convertible Rational Word16 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Word16 Rational where + safeConvert = return . fromIntegral++instance Convertible Rational Word32 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Word32 Rational where + safeConvert = return . fromIntegral++instance Convertible Rational Word64 where + safeConvert = boundedConversion (return . truncate)+instance Convertible Word64 Rational where + safeConvert = return . fromIntegral+++------------------------------------------------------------+{- The following instances generated by this code:++int = ["Int", "Int8", "Int16", "Int32", "Int64", "Word", "Word8", "Word16", "Word32",+ "Word64"]+allItems l1 l2 = concatMap (\x -> map (\y -> (x, y)) l1) l2+work = filter (\(a, b) -> a /= b) (allItems int int)+printIt (f, i) = + "instance Convertible " ++ f ++ " " ++ i ++ " where \n\+ \ safeConvert = boundedConversion (return . fromIntegral)\n"++printInteger i =+ "instance Convertible Integer " ++ i ++ " where \n\+ \ safeConvert = boundedConversion (return . fromIntegral)\n\+ \instance Convertible " ++ i ++ " Integer where \n\+ \ safeConvert = return . fromIntegral\n\n"++main = do mapM_ (putStrLn . printIt) work+ mapM_ (putStrLn . printInteger) int+-}++instance Convertible Int Int8 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int Int16 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int Int32 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int Int64 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int Word where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int Word8 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int Word16 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int Word32 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int Word64 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int8 Int where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int8 Int16 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int8 Int32 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int8 Int64 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int8 Word where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int8 Word8 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int8 Word16 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int8 Word32 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int8 Word64 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int16 Int where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int16 Int8 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int16 Int32 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int16 Int64 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int16 Word where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int16 Word8 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int16 Word16 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int16 Word32 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int16 Word64 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int32 Int where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int32 Int8 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int32 Int16 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int32 Int64 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int32 Word where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int32 Word8 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int32 Word16 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int32 Word32 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int32 Word64 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int64 Int where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int64 Int8 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int64 Int16 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int64 Int32 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int64 Word where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int64 Word8 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int64 Word16 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int64 Word32 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Int64 Word64 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word Int where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word Int8 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word Int16 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word Int32 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word Int64 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word Word8 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word Word16 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word Word32 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word Word64 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word8 Int where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word8 Int8 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word8 Int16 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word8 Int32 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word8 Int64 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word8 Word where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word8 Word16 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word8 Word32 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word8 Word64 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word16 Int where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word16 Int8 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word16 Int16 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word16 Int32 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word16 Int64 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word16 Word where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word16 Word8 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word16 Word32 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word16 Word64 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word32 Int where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word32 Int8 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word32 Int16 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word32 Int32 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word32 Int64 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word32 Word where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word32 Word8 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word32 Word16 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word32 Word64 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word64 Int where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word64 Int8 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word64 Int16 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word64 Int32 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word64 Int64 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word64 Word where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word64 Word8 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word64 Word16 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Word64 Word32 where + safeConvert = boundedConversion (return . fromIntegral)++instance Convertible Integer Int where + safeConvert = boundedConversion (return . fromIntegral)+instance Convertible Int Integer where + safeConvert = return . fromIntegral+++instance Convertible Integer Int8 where + safeConvert = boundedConversion (return . fromIntegral)+instance Convertible Int8 Integer where + safeConvert = return . fromIntegral+++instance Convertible Integer Int16 where + safeConvert = boundedConversion (return . fromIntegral)+instance Convertible Int16 Integer where + safeConvert = return . fromIntegral+++instance Convertible Integer Int32 where + safeConvert = boundedConversion (return . fromIntegral)+instance Convertible Int32 Integer where + safeConvert = return . fromIntegral+++instance Convertible Integer Int64 where + safeConvert = boundedConversion (return . fromIntegral)+instance Convertible Int64 Integer where + safeConvert = return . fromIntegral+++instance Convertible Integer Word where + safeConvert = boundedConversion (return . fromIntegral)+instance Convertible Word Integer where + safeConvert = return . fromIntegral+++instance Convertible Integer Word8 where + safeConvert = boundedConversion (return . fromIntegral)+instance Convertible Word8 Integer where + safeConvert = return . fromIntegral+++instance Convertible Integer Word16 where + safeConvert = boundedConversion (return . fromIntegral)+instance Convertible Word16 Integer where + safeConvert = return . fromIntegral+++instance Convertible Integer Word32 where + safeConvert = boundedConversion (return . fromIntegral)+instance Convertible Word32 Integer where + safeConvert = return . fromIntegral+++instance Convertible Integer Word64 where + safeConvert = boundedConversion (return . fromIntegral)+instance Convertible Word64 Integer where + safeConvert = return . fromIntegral+++------------------------------------------------------------++instance Convertible Integer Double where+ safeConvert = return . fromIntegral+instance Convertible Integer Float where+ safeConvert = return . fromIntegral+instance Convertible Integer Rational where+ safeConvert = return . fromIntegral+instance Convertible Double Integer where+ safeConvert = return . truncate+instance Convertible Float Integer where+ safeConvert = return . truncate+instance Convertible Rational Integer where+ safeConvert = return . truncate++instance Convertible Float Double where+ safeConvert = return . fromRational . toRational+instance Convertible Double Float where+ safeConvert = return . fromRational . toRational+instance Convertible Float Rational where+ safeConvert = return . toRational+instance Convertible Rational Float where+ safeConvert = return . fromRational+instance Convertible Double Rational where+ safeConvert = return . toRational+instance Convertible Rational Double where+ safeConvert = return . fromRational++------------------------------------------------------------+instance Convertible Char Integer where+ safeConvert = return . fromIntegral . fromEnum+instance Convertible Integer Char where+ safeConvert = boundedConversion (return . toEnum . fromIntegral)++------------------------------------------------------------+{- These instances generated by:++int = ["Int", "Int8", "Int16", "Int32", "Int64", "Word", "Word8", "Word16", "Word32",+ "Word64"]+printIt i = + "instance Convertible Char " ++ i ++ " where \n\+ \ safeConvert = boundedConversion (return . fromIntegral . fromEnum)\n\+ \instance Convertible " ++ i ++ " Char where \n\+ \ safeConvert = boundedConversion (return . toEnum . fromIntegral)\n\n"++main = do mapM_ (putStrLn . printIt) int+-}++instance Convertible Char Int where + safeConvert = boundedConversion (return . fromIntegral . fromEnum)+instance Convertible Int Char where + safeConvert = boundedConversion (return . toEnum . fromIntegral)+++instance Convertible Char Int8 where + safeConvert = boundedConversion (return . fromIntegral . fromEnum)+instance Convertible Int8 Char where + safeConvert = boundedConversion (return . toEnum . fromIntegral)+++instance Convertible Char Int16 where + safeConvert = boundedConversion (return . fromIntegral . fromEnum)+instance Convertible Int16 Char where + safeConvert = boundedConversion (return . toEnum . fromIntegral)+++instance Convertible Char Int32 where + safeConvert = boundedConversion (return . fromIntegral . fromEnum)+instance Convertible Int32 Char where + safeConvert = boundedConversion (return . toEnum . fromIntegral)+++instance Convertible Char Int64 where + safeConvert = boundedConversion (return . fromIntegral . fromEnum)+instance Convertible Int64 Char where + safeConvert = boundedConversion (return . toEnum . fromIntegral)+++instance Convertible Char Word where + safeConvert = boundedConversion (return . fromIntegral . fromEnum)+instance Convertible Word Char where + safeConvert = boundedConversion (return . toEnum . fromIntegral)+++instance Convertible Char Word8 where + safeConvert = boundedConversion (return . fromIntegral . fromEnum)+instance Convertible Word8 Char where + safeConvert = boundedConversion (return . toEnum . fromIntegral)+++instance Convertible Char Word16 where + safeConvert = boundedConversion (return . fromIntegral . fromEnum)+instance Convertible Word16 Char where + safeConvert = boundedConversion (return . toEnum . fromIntegral)+++instance Convertible Char Word32 where + safeConvert = boundedConversion (return . fromIntegral . fromEnum)+instance Convertible Word32 Char where + safeConvert = boundedConversion (return . toEnum . fromIntegral)+++instance Convertible Char Word64 where + safeConvert = boundedConversion (return . fromIntegral . fromEnum)+instance Convertible Word64 Char where + safeConvert = boundedConversion (return . toEnum . fromIntegral)+++instance Convertible Integer Integer where+ safeConvert = return . id
+ Data/Convertible/Instances/Time.hs view
@@ -0,0 +1,212 @@+{- |+ Module : Data.Convertible.Instances.Time+ Copyright : Copyright (C) 2009 John Goerzen+ License : LGPL++ Maintainer : John Goerzen <jgoerzen@complete.org>+ Stability : provisional+ Portability: portable++Instances to convert between various time structures, both old- and new-style.++At present, this module does not do full input validation. That is, it is possible+to get an exception rather than a Left result from these functions if your input is+invalid, particularly when converting from the old-style System.Time structures.++Copyright (C) 2009 John Goerzen <jgoerzen@complete.org>++All rights reserved.++For license and copyright information, see the file COPYRIGHT++-}++module Data.Convertible.Instances.Time()+where++import Data.Convertible.Base+import Data.Convertible.Utils+import Data.Convertible.Instances.Num()+import qualified System.Time as ST+import Data.Time+import Data.Time.Clock+import Data.Time.Clock.POSIX+import Data.Time.Calendar.OrdinalDate+import Data.Typeable+import Data.Ratio++----------------------------------------------------------------------+-- Intra-System.Time stuff+----------------------------------------------------------------------++instance Convertible ST.ClockTime ST.CalendarTime where+ safeConvert = return . ST.toUTCTime++instance Convertible ST.CalendarTime ST.ClockTime where+ safeConvert = return . ST.toClockTime++instance Convertible ST.ClockTime Integer where+ safeConvert (ST.TOD x _) = return x++instance Convertible Integer ST.ClockTime where+ safeConvert x = return $ ST.TOD x 0++----------------------------------------------------------------------+-- Intra-Data.Time stuff+----------------------------------------------------------------------++------------------------------ POSIX and UTC times++instance Typeable NominalDiffTime where+ typeOf _ = mkTypeName "NominalDiffTime"++instance Typeable UTCTime where+ typeOf _ = mkTypeName "UTCTime"++{- Covered under Real a+instance Convertible Rational POSIXTime where+ safeConvert = return . fromRational+-}++instance Convertible Rational POSIXTime where+ safeConvert = return . fromRational+instance Convertible Integer POSIXTime where+ safeConvert = return . fromInteger+instance Convertible Int POSIXTime where+ safeConvert = return . fromIntegral+instance Convertible Double POSIXTime where+ safeConvert = return . fromRational . toRational++instance Convertible POSIXTime Integer where+ safeConvert = return . truncate+instance Convertible POSIXTime Rational where+ safeConvert = return . toRational+instance Convertible POSIXTime Double where+ safeConvert = return . fromRational . toRational+instance Convertible POSIXTime Int where+ safeConvert = boundedConversion (return . truncate)++instance Convertible POSIXTime UTCTime where+ safeConvert = return . posixSecondsToUTCTime+instance Convertible UTCTime POSIXTime where+ safeConvert = return . utcTimeToPOSIXSeconds++instance Convertible Rational UTCTime where+ safeConvert a = safeConvert a >>= return . posixSecondsToUTCTime+instance Convertible Integer UTCTime where+ safeConvert a = safeConvert a >>= return . posixSecondsToUTCTime+instance Convertible Int UTCTime where+ safeConvert a = safeConvert a >>= return . posixSecondsToUTCTime+instance Convertible Double UTCTime where+ safeConvert a = safeConvert a >>= return . posixSecondsToUTCTime++instance Convertible UTCTime Rational where+ safeConvert = safeConvert . utcTimeToPOSIXSeconds+instance Convertible UTCTime Integer where+ safeConvert = safeConvert . utcTimeToPOSIXSeconds+instance Convertible UTCTime Double where+ safeConvert = safeConvert . utcTimeToPOSIXSeconds+instance Convertible UTCTime Int where+ safeConvert = boundedConversion (safeConvert . utcTimeToPOSIXSeconds)++------------------------------ LocalTime stuff++instance Convertible UTCTime ZonedTime where+ safeConvert = return . utcToZonedTime utc+instance Convertible POSIXTime ZonedTime where+ safeConvert = return . utcToZonedTime utc . posixSecondsToUTCTime+instance Convertible ZonedTime UTCTime where+ safeConvert = return . zonedTimeToUTC+instance Convertible ZonedTime POSIXTime where+ safeConvert = return . utcTimeToPOSIXSeconds . zonedTimeToUTC++{- Too obvious?+instance Convertible LocalTime Day where+ safeConvert = return . localDay+instance Convertible LocalTime TimeOfDay where+ safeConvert = return . localTimeOfDay+-}++----------------------------------------------------------------------+-- Conversions between old and new time+----------------------------------------------------------------------+instance Convertible ST.CalendarTime ZonedTime where+ safeConvert ct = return $ ZonedTime {+ zonedTimeToLocalTime = LocalTime {+ localDay = fromGregorian (fromIntegral $ ST.ctYear ct) + (1 + (fromEnum $ ST.ctMonth ct))+ (ST.ctDay ct),+ localTimeOfDay = TimeOfDay {+ todHour = ST.ctHour ct,+ todMin = ST.ctMin ct,+ todSec = (fromIntegral $ ST.ctSec ct) + + fromRational (ST.ctPicosec ct % 1000000000000)+ }+ },+ zonedTimeZone = TimeZone {+ timeZoneMinutes = ST.ctTZ ct `div` 60,+ timeZoneSummerOnly = ST.ctIsDST ct,+ timeZoneName = ST.ctTZName ct}+}++instance Convertible ST.CalendarTime POSIXTime where+ safeConvert a = do r <- (safeConvert a)::ConvertResult ST.ClockTime+ safeConvert r+instance Convertible ST.CalendarTime UTCTime where+ safeConvert a = do r <- (safeConvert a)::ConvertResult POSIXTime+ safeConvert r++instance Convertible ST.ClockTime POSIXTime where+ safeConvert (ST.TOD x y) = return $ fromRational $ + fromInteger x `plusorminus` fromRational (y % 1000000000000)+ where plusorminus = if x < 0 then (-) else (+)+instance Convertible ST.ClockTime UTCTime where+ safeConvert a = do r <- (safeConvert a)::ConvertResult POSIXTime+ safeConvert r+instance Convertible ST.ClockTime ZonedTime where+ safeConvert a = do r <- (safeConvert a)::ConvertResult UTCTime+ safeConvert r++instance Convertible POSIXTime ST.ClockTime where+ safeConvert x = return $ ST.TOD rsecs rpico+ where rsecs = (truncate x :: Integer)+ rpico = truncate $ abs $ 1000000000000 * (x - (fromIntegral rsecs))+instance Convertible UTCTime ST.ClockTime where+ safeConvert = safeConvert . utcTimeToPOSIXSeconds++instance Convertible ZonedTime ST.CalendarTime where+ safeConvert zt = return $ ST.CalendarTime {+ ST.ctYear = fromIntegral year,+ ST.ctMonth = toEnum (month - 1),+ ST.ctDay = day,+ ST.ctHour = todHour ltod,+ ST.ctMin = todMin ltod,+ ST.ctSec = secs,+ ST.ctPicosec = truncate $ (((toRational (todSec ltod) - (toRational secs)) * 1000000000000)::Rational),+ ST.ctWDay = toEnum . snd . sundayStartWeek . localDay . zonedTimeToLocalTime $ zt,+ ST.ctYDay = snd . toOrdinalDate . localDay . zonedTimeToLocalTime $ zt,+ ST.ctTZName = timeZoneName . zonedTimeZone $ zt,+ ST.ctTZ = (timeZoneMinutes . zonedTimeZone $ zt) * 60,+ ST.ctIsDST = timeZoneSummerOnly . zonedTimeZone $ zt+ }+ where (year, month, day) = toGregorian . localDay . zonedTimeToLocalTime $ zt+ ltod = localTimeOfDay . zonedTimeToLocalTime $ zt+ secs = (truncate . todSec $ ltod)::Int+instance Convertible POSIXTime ST.CalendarTime where+ safeConvert pt = do r <- (safeConvert pt)::ConvertResult ZonedTime+ safeConvert r+instance Convertible UTCTime ST.CalendarTime where+ safeConvert = safeConvert . utcTimeToPOSIXSeconds++instance Convertible ST.TimeDiff NominalDiffTime where+ {- This is a clever hack. We convert the TimeDiff to a ClockTime, applying+ it as a diff vs. the epoch. Converting this ClockTime to a POSIXTime yiels+ the NominalDiffTime we want, since a POSIXTime is a NominalDiffTime vs. the+ epoch. -}+ safeConvert td = safeConvert clockTime+ where clockTime = ST.addToClockTime td (ST.TOD 0 0)+instance Convertible NominalDiffTime ST.TimeDiff where+ {- Similar clever hack as above. -}+ safeConvert ndt =+ do clockt <- safeConvert ndt+ return (ST.diffClockTimes clockt (ST.TOD 0 0))
+ Data/Convertible/Utils.hs view
@@ -0,0 +1,52 @@+{-+Copyright (C) 2009 John Goerzen <jgoerzen@complete.org>++All rights reserved.++For license and copyright information, see the file COPYRIGHT++-}++{- |+ Module : Data.Convertible.Utils+ Copyright : Copyright (C) 2009 John Goerzen+ License : LGPL++ Maintainer : John Goerzen <jgoerzen@complete.org>+ Stability : provisional+ Portability: portable++-}++module Data.Convertible.Utils(boundedConversion,+ mkTypeName+ )+where+import Data.Convertible.Base+import Data.Typeable++{- | Utility function to perform bounds checking as part of a conversion.++Does this be examining the bounds of the destination type, converting to the type of+the source via 'safeConvert', comparing to the source value. Results in an error+if the conversion is out of bounds. -}+boundedConversion :: (Ord a, Bounded b, Show a, Show b, Convertible a Integer,+ Convertible b Integer,+ Typeable a, Typeable b) => + (a -> ConvertResult b) -- ^ Function to do the conversion+ -> a -- ^ Input data+ -> ConvertResult b -- ^ Result+boundedConversion func inp =+ do result <- func inp+ let smallest = asTypeOf minBound result+ let biggest = asTypeOf maxBound result+ let smallest' = (convert smallest)::Integer+ let biggest' = (convert biggest)::Integer+ let inp' = (convert inp)::Integer+ if inp' < smallest' || inp' > biggest'+ then convError ("Input value outside of bounds: " ++ show (smallest, biggest))+ inp+ else return result++mkTypeName :: String -> TypeRep+mkTypeName name = mkTyConApp (mkTyCon name) []
+ Setup.lhs view
@@ -0,0 +1,6 @@+#!/usr/bin/env runhaskell++> import Distribution.Simple++> main = defaultMain+
+ convertible.cabal view
@@ -0,0 +1,78 @@+Name: convertible+Version: 1.0.0+License: LGPL+Maintainer: John Goerzen <jgoerzen@complete.org>+Author: John Goerzen+Copyright: Copyright (c) 2009-2009 John Goerzen+license-file: COPYRIGHT+extra-source-files: COPYING+homepage: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/convertible+Category: Data+synopsis: Typeclasses and instances for converting between types+Description: convertible provides a typeclass with a single function+ that is designed to help convert between different types: numeric+ values, dates and times, and the like. The conversions perform bounds+ checking and return a pure Either value. This means that you need+ not remember which specific function performs the conversion you+ desire.+ .+ Also included in the package are optional instances that provide+ conversion for various numeric and time types, as well as utilities+ for writing your own instances.+ .+ Finally, there is a function that will raise an exception on+ bounds-checking violation, or return a bare value otherwise,+ implemented in terms of the safer function described above.+ .+ Convertible is also used by HDBC 2.0 for handling marshalling of+ data to/from databases.+ .+ Convertible is backed by an extensive test suite and passes tests+ on GHC and Hugs.+Stability: Stable+Build-Type: Simple++Cabal-Version: >=1.2++flag splitBase+ description: Choose the new smaller, split-up base package.+flag buildtests+ description: Build the executable to run unit tests+ default: False++library+ if flag(splitBase)+ Build-Depends: base>=3, old-time, time, bytestring, containers, old-locale+ else+ Build-Depends: base<3+ Build-Depends: mtl++ GHC-Options: -O2 -Wall -fno-warn-orphans++ Exposed-Modules: Data.Convertible,+ Data.Convertible.Base,+ Data.Convertible.Utils,+ Data.Convertible.Instances,+ Data.Convertible.Instances.Map,+ Data.Convertible.Instances.Num,+ Data.Convertible.Instances.Time++ --Other-Modules: Database.HDBC.Utils+ --Extensions: ExistentialQuantification, AllowOverlappingInstances,+ -- AllowUndecidableInstances+ Extensions: ExistentialQuantification, MultiParamTypeClasses,+ UndecidableInstances, FlexibleInstances,+ FlexibleContexts, TypeSynonymInstances+ +Executable runtests+ if flag(buildtests)+ Buildable: True+ else+ Buildable: False+ Build-Depends: HUnit, QuickCheck, testpack+ Main-Is: runtests.hs+ Hs-Source-Dirs: ., testsrc+ GHC-Options: -O2+ Extensions: ExistentialQuantification, MultiParamTypeClasses,+ UndecidableInstances, FlexibleInstances,+ FlexibleContexts, TypeSynonymInstances