diff --git a/Setup.hs b/Setup.hs --- a/Setup.hs +++ b/Setup.hs @@ -1,6 +1,15 @@ module Main (main) where -import Distribution.Simple +import Distribution.Simple ( defaultMainWithHooks, simpleUserHooks + , UserHooks(runTests)) +import System.Cmd (system) main :: IO () -main = defaultMain +main = defaultMainWithHooks hooks + where hooks = simpleUserHooks { runTests = runTests' } + +-- Runs the testsuite +runTests' _ _ _ _ = system cmd >> return () + where testdir = "tests" + testcmd = "runhaskell ./Main.hs" + cmd = "cd " ++ testdir ++ " && " ++ testcmd diff --git a/src/Data/Generics.hs b/src/Data/Generics.hs --- a/src/Data/Generics.hs +++ b/src/Data/Generics.hs @@ -1,8 +1,10 @@ +{-# OPTIONS_GHC -cpp #-} + ----------------------------------------------------------------------------- -- | -- Module : Data.Generics -- Copyright : (c) The University of Glasgow, CWI 2001--2004 --- License : BSD-style (see the file libraries/base/LICENSE) +-- License : BSD-style (see the LICENSE file) -- -- Maintainer : generics@haskell.org -- Stability : experimental @@ -26,19 +28,20 @@ module Data.Generics.Schemes, -- traversal schemes (everywhere etc.) module Data.Generics.Text, -- generic read and show module Data.Generics.Twins, -- twin traversal, e.g., generic eq + module Data.Generics.Builders, -- term builders +#ifdef __GLASGOW_HASKELL__ #ifndef __HADDOCK__ -- Data types for the sum-of-products type encoding; -- included for backwards compatibility; maybe obsolete. (:*:)(..), (:+:)(..), Unit(..) #endif +#endif ) where ------------------------------------------------------------------------------ -import Prelude -- So that 'make depend' works - #ifdef __GLASGOW_HASKELL__ #ifndef __HADDOCK__ -- Data types for the sum-of-products type encoding; @@ -53,3 +56,4 @@ import Data.Generics.Schemes import Data.Generics.Text import Data.Generics.Twins +import Data.Generics.Builders diff --git a/src/Data/Generics/Aliases.hs b/src/Data/Generics/Aliases.hs --- a/src/Data/Generics/Aliases.hs +++ b/src/Data/Generics/Aliases.hs @@ -1,8 +1,11 @@ +{-# OPTIONS_GHC -cpp #-} +{-# LANGUAGE Rank2Types #-} + ----------------------------------------------------------------------------- -- | -- Module : Data.Generics.Aliases -- Copyright : (c) The University of Glasgow, CWI 2001--2004 --- License : BSD-style (see the file libraries/base/LICENSE) +-- License : BSD-style (see the LICENSE file) -- -- Maintainer : generics@haskell.org -- Stability : experimental @@ -33,7 +36,7 @@ GenericQ'(..), GenericM'(..), - -- * Inredients of generic functions + -- * Ingredients of generic functions orElse, -- * Function combinators on generic functions @@ -46,7 +49,8 @@ ext1T, ext1M, ext1Q, - ext1R + ext1R, + ext1B ) where @@ -109,7 +113,7 @@ {- For the remaining definitions, we stick to a more concise style, i.e., -we fold maybies with "maybe" instead of case ... of ..., and we also +we fold maybes with "maybe" instead of case ... of ..., and we also use a point-free style whenever possible. -} @@ -254,12 +258,12 @@ -- | Other first-class polymorphic wrappers -newtype GenericT' = GT { unGT :: Data a => a -> a } +newtype GenericT' = GT { unGT :: forall a. Data a => a -> a } newtype GenericQ' r = GQ { unGQ :: GenericQ r } -newtype GenericM' m = GM { unGM :: Data a => a -> m a } +newtype GenericM' m = GM { unGM :: forall a. Data a => a -> m a } --- | Left-biased choice on maybies +-- | Left-biased choice on maybes orElse :: Maybe a -> Maybe a -> Maybe a x `orElse` y = case x of Just _ -> x @@ -347,6 +351,12 @@ ext1R def ext = unR ((R def) `ext1` (R ext)) +-- | Type extension of builders for type constructors +ext1B :: (Data a, Typeable1 t) + => a + -> (forall b. Data b => (t b)) + -> a +ext1B def ext = unB ((B def) `ext1` (B ext)) ------------------------------------------------------------------------------ -- @@ -366,3 +376,6 @@ -- | The type constructor for readers newtype R m x = R { unR :: m x } + +-- | The type constructor for builders +newtype B x = B {unB :: x} diff --git a/src/Data/Generics/Basics.hs b/src/Data/Generics/Basics.hs --- a/src/Data/Generics/Basics.hs +++ b/src/Data/Generics/Basics.hs @@ -2,7 +2,7 @@ -- | -- Module : Data.Generics.Basics -- Copyright : (c) The University of Glasgow, CWI 2001--2004 --- License : BSD-style (see the file libraries/base/LICENSE) +-- License : BSD-style (see the LICENSE file) -- -- Maintainer : generics@haskell.org -- Stability : experimental diff --git a/src/Data/Generics/Builders.hs b/src/Data/Generics/Builders.hs new file mode 100644 --- /dev/null +++ b/src/Data/Generics/Builders.hs @@ -0,0 +1,65 @@ +{-# LANGUAGE ScopedTypeVariables #-} +{-# LANGUAGE FlexibleContexts #-} + +----------------------------------------------------------------------------- +-- | +-- Module : Data.Generics.Builders +-- Copyright : (c) 2008 Universiteit Utrecht +-- License : BSD-style +-- +-- Maintainer : generics@haskell.org +-- Stability : experimental +-- Portability : non-portable +-- +-- This module provides generic builder functions. These functions construct +-- values of a given type. +----------------------------------------------------------------------------- + +module Data.Generics.Builders (empty, constrs) where + +import Data.Data +import Data.Generics.Aliases (extB) + +-- | Construct the empty value for a datatype. For algebraic datatypes, the +-- leftmost constructor is chosen. +empty :: forall a. Data a => a +empty = general + `extB` char + `extB` int + `extB` integer + `extB` float + `extB` double where + -- Generic case + general :: Data a => a + general = fromConstrB empty (indexConstr (dataTypeOf general) 1) + + -- Base cases + char = '\NUL' + int = 0 :: Int + integer = 0 :: Integer + float = 0.0 :: Float + double = 0.0 :: Double + + +-- | Return a list of values of a datatype. Each value is one of the possible +-- constructors of the datatype, populated with 'empty' values. +constrs :: forall a. Data a => [a] +constrs = general + `extB` char + `extB` int + `extB` integer + `extB` float + `extB` double where + -- Generic case + general :: Data a => [a] + general = map (fromConstrB empty) + (dataTypeConstrs (dataTypeOf (unList general))) where + unList :: Data a => [a] -> a + unList = undefined + + -- Base cases + char = "\NUL" + int = [0 :: Int] + integer = [0 :: Integer] + float = [0.0 :: Float] + double = [0.0 :: Double] diff --git a/src/Data/Generics/Instances.hs b/src/Data/Generics/Instances.hs --- a/src/Data/Generics/Instances.hs +++ b/src/Data/Generics/Instances.hs @@ -1,8 +1,10 @@ +{-# OPTIONS_GHC -cpp #-} + ----------------------------------------------------------------------------- -- | -- Module : Data.Generics.Instances -- Copyright : (c) The University of Glasgow, CWI 2001--2004 --- License : BSD-style (see the file libraries/base/LICENSE) +-- License : BSD-style (see the LICENSE file) -- -- Maintainer : generics@haskell.org -- Stability : experimental @@ -27,18 +29,19 @@ ------------------------------------------------------------------------------ -#ifdef __HADDOCK__ -import Prelude -#endif - import Data.Data -import Data.Typeable #ifdef __GLASGOW_HASKELL__ +#if __GLASGOW_HASKELL__ >= 611 +import GHC.IO.Handle -- So we can give Data instance for Handle +#else import GHC.IOBase -- So we can give Data instance for IO, Handle +#endif import GHC.Stable -- So we can give Data instance for StablePtr import GHC.ST -- So we can give Data instance for ST -import GHC.Conc -- So we can give Data instance for MVar & Co. +import GHC.Conc -- So we can give Data instance for TVar +import Data.IORef -- So we can give Data instance for IORef +import Control.Concurrent -- So we can give Data instance for MVar #else # ifdef __HUGS__ import Hugs.Prelude( Ratio(..) ) @@ -48,13 +51,19 @@ import Foreign.ForeignPtr import Foreign.StablePtr import Control.Monad.ST -import Control.Concurrent -import Data.IORef #endif #include "Typeable.h" +-- Version compatibility issues caused by #2760 +myMkNoRepType :: String -> DataType +#if __GLASGOW_HASKELL__ >= 611 +myMkNoRepType = mkNoRepType +#else +myMkNoRepType = mkNorepType +#endif + ------------------------------------------------------------------------------ -- -- Instances of the Data class for Prelude-like types. @@ -70,7 +79,7 @@ instance Data TypeRep where toConstr _ = error "toConstr" gunfold _ _ = error "gunfold" - dataTypeOf _ = mkNorepType "Data.Typeable.TypeRep" + dataTypeOf _ = myMkNoRepType "Data.Typeable.TypeRep" ------------------------------------------------------------------------------ @@ -78,7 +87,7 @@ instance Data TyCon where toConstr _ = error "toConstr" gunfold _ _ = error "gunfold" - dataTypeOf _ = mkNorepType "Data.Typeable.TyCon" + dataTypeOf _ = myMkNoRepType "Data.Typeable.TyCon" ------------------------------------------------------------------------------ @@ -88,7 +97,7 @@ instance Data DataType where toConstr _ = error "toConstr" gunfold _ _ = error "gunfold" - dataTypeOf _ = mkNorepType "Data.Generics.Basics.DataType" + dataTypeOf _ = myMkNoRepType "Data.Generics.Basics.DataType" ------------------------------------------------------------------------------ @@ -96,7 +105,7 @@ instance Data Handle where toConstr _ = error "toConstr" gunfold _ _ = error "gunfold" - dataTypeOf _ = mkNorepType "GHC.IOBase.Handle" + dataTypeOf _ = myMkNoRepType "GHC.IOBase.Handle" ------------------------------------------------------------------------------ @@ -104,7 +113,7 @@ instance Typeable a => Data (StablePtr a) where toConstr _ = error "toConstr" gunfold _ _ = error "gunfold" - dataTypeOf _ = mkNorepType "GHC.Stable.StablePtr" + dataTypeOf _ = myMkNoRepType "GHC.Stable.StablePtr" ------------------------------------------------------------------------------ @@ -113,7 +122,7 @@ instance Data ThreadId where toConstr _ = error "toConstr" gunfold _ _ = error "gunfold" - dataTypeOf _ = mkNorepType "GHC.Conc.ThreadId" + dataTypeOf _ = myMkNoRepType "GHC.Conc.ThreadId" #endif @@ -125,7 +134,7 @@ instance Typeable a => Data (TVar a) where toConstr _ = error "toConstr" gunfold _ _ = error "gunfold" - dataTypeOf _ = mkNorepType "GHC.Conc.TVar" + dataTypeOf _ = myMkNoRepType "GHC.Conc.TVar" #endif @@ -134,7 +143,7 @@ instance Typeable a => Data (MVar a) where toConstr _ = error "toConstr" gunfold _ _ = error "gunfold" - dataTypeOf _ = mkNorepType "GHC.Conc.MVar" + dataTypeOf _ = myMkNoRepType "GHC.Conc.MVar" ------------------------------------------------------------------------------ @@ -143,7 +152,7 @@ instance Typeable a => Data (STM a) where toConstr _ = error "toConstr" gunfold _ _ = error "gunfold" - dataTypeOf _ = mkNorepType "GHC.Conc.STM" + dataTypeOf _ = myMkNoRepType "GHC.Conc.STM" #endif @@ -152,7 +161,7 @@ instance (Typeable s, Typeable a) => Data (ST s a) where toConstr _ = error "toConstr" gunfold _ _ = error "gunfold" - dataTypeOf _ = mkNorepType "GHC.ST.ST" + dataTypeOf _ = myMkNoRepType "GHC.ST.ST" ------------------------------------------------------------------------------ @@ -160,7 +169,7 @@ instance Typeable a => Data (IORef a) where toConstr _ = error "toConstr" gunfold _ _ = error "gunfold" - dataTypeOf _ = mkNorepType "GHC.IOBase.IORef" + dataTypeOf _ = myMkNoRepType "GHC.IOBase.IORef" ------------------------------------------------------------------------------ @@ -168,7 +177,7 @@ instance Typeable a => Data (IO a) where toConstr _ = error "toConstr" gunfold _ _ = error "gunfold" - dataTypeOf _ = mkNorepType "GHC.IOBase.IO" + dataTypeOf _ = myMkNoRepType "GHC.IOBase.IO" ------------------------------------------------------------------------------ @@ -179,6 +188,6 @@ instance (Data a, Data b) => Data (a -> b) where toConstr _ = error "toConstr" gunfold _ _ = error "gunfold" - dataTypeOf _ = mkNorepType "Prelude.(->)" + dataTypeOf _ = myMkNoRepType "Prelude.(->)" dataCast2 f = gcast2 f diff --git a/src/Data/Generics/Schemes.hs b/src/Data/Generics/Schemes.hs --- a/src/Data/Generics/Schemes.hs +++ b/src/Data/Generics/Schemes.hs @@ -1,8 +1,12 @@ +{-# OPTIONS_GHC -cpp #-} +{-# LANGUAGE Rank2Types #-} +{-# LANGUAGE ScopedTypeVariables #-} + ----------------------------------------------------------------------------- -- | -- Module : Data.Generics.Schemes -- Copyright : (c) The University of Glasgow, CWI 2001--2003 --- License : BSD-style (see the file libraries/base/LICENSE) +-- License : BSD-style (see the LICENSE file) -- -- Maintainer : generics@haskell.org -- Stability : experimental diff --git a/src/Data/Generics/Text.hs b/src/Data/Generics/Text.hs --- a/src/Data/Generics/Text.hs +++ b/src/Data/Generics/Text.hs @@ -1,8 +1,10 @@ +{-# OPTIONS_GHC -cpp #-} + ----------------------------------------------------------------------------- -- | -- Module : Data.Generics.Text -- Copyright : (c) The University of Glasgow, CWI 2001--2003 --- License : BSD-style (see the file libraries/base/LICENSE) +-- License : BSD-style (see the LICENSE file) -- -- Maintainer : generics@haskell.org -- Stability : experimental @@ -16,9 +18,12 @@ module Data.Generics.Text ( - gshow, - gread + -- * Generic show + gshow, gshows, + -- * Generic read + gread + ) where ------------------------------------------------------------------------------ @@ -27,7 +32,6 @@ import Prelude #endif import Control.Monad -import Data.Maybe import Data.Data import Data.Generics.Aliases import Text.ParserCombinators.ReadP @@ -37,17 +41,19 @@ -- | Generic show: an alternative to \"deriving Show\" gshow :: Data a => a -> String +gshow x = gshows x "" +-- | Generic shows +gshows :: Data a => a -> ShowS + -- This is a prefix-show using surrounding "(" and ")", -- where we recurse into subterms with gmapQ. --- -gshow = ( \t -> - "(" - ++ showConstr (toConstr t) - ++ concat (gmapQ ((++) " " . gshow) t) - ++ ")" - ) `extQ` (show :: String -> String) - +gshows = ( \t -> + showChar '(' + . (showString . showConstr . toConstr $ t) + . (foldr (.) id . gmapQ ((showChar ' ' .) . gshows) $ t) + . showChar ')' + ) `extQ` (shows :: String -> ShowS) -- | Generic read: an alternative to \"deriving Read\" @@ -88,7 +94,7 @@ do -- Drop " ( " skipSpaces -- Discard leading space - char '(' -- Parse '(' + _ <- char '(' -- Parse '(' skipSpaces -- Discard following space -- Do the real work @@ -98,7 +104,7 @@ -- Drop " ) " skipSpaces -- Discard leading space - char ')' -- Parse ')' + _ <- char ')' -- Parse ')' skipSpaces -- Discard following space return x @@ -113,6 +119,7 @@ parseConstr :: ReadP String parseConstr = string "[]" -- Compound lexeme "[]" + <++ string "()" -- singleton "()" <++ infixOp -- Infix operator in parantheses <++ readS_to_P lex -- Ordinary constructors and literals diff --git a/src/Data/Generics/Twins.hs b/src/Data/Generics/Twins.hs --- a/src/Data/Generics/Twins.hs +++ b/src/Data/Generics/Twins.hs @@ -1,8 +1,11 @@ +{-# OPTIONS_GHC -cpp #-} +{-# LANGUAGE Rank2Types #-} + ----------------------------------------------------------------------------- -- | -- Module : Data.Generics.Twins -- Copyright : (c) The University of Glasgow, CWI 2001--2004 --- License : BSD-style (see the file libraries/base/LICENSE) +-- License : BSD-style (see the LICENSE file) -- -- Maintainer : generics@haskell.org -- Stability : experimental @@ -24,6 +27,7 @@ gmapAccumQl, gmapAccumQr, gmapAccumQ, + gmapAccumA, -- * Mapping combinators for twin traversal gzipWithT, @@ -49,6 +53,8 @@ import Prelude hiding ( GT ) #endif +import Control.Applicative (Applicative(..)) + ------------------------------------------------------------------------------ @@ -100,6 +106,22 @@ k a (ID c) d = let (a',d') = f a d in (a', ID (c d')) z a x = (a, ID x) + + +-- | Applicative version +gmapAccumA :: forall b d a. (Data d, Applicative a) + => (forall e. Data e => b -> e -> (b, a e)) + -> b -> d -> (b, a d) +gmapAccumA f a0 d0 = gfoldlAccum k z a0 d0 + where + k :: forall d' e. (Data d') => + b -> a (d' -> e) -> d' -> (b, a e) + k a c d = let (a',d') = f a d + c' = c <*> d' + in (a', c') + z :: forall t c a'. (Applicative a') => + t -> c -> (t, a' c) + z a x = (a, pure x) -- | gmapM with accumulation diff --git a/src/Generics/SYB.hs b/src/Generics/SYB.hs new file mode 100644 --- /dev/null +++ b/src/Generics/SYB.hs @@ -0,0 +1,17 @@ +----------------------------------------------------------------------------- +-- | +-- Module : Generics.SYB +-- Copyright : (c) The University of Glasgow, CWI 2001--2004 +-- License : BSD-style (see the file libraries/base/LICENSE) +-- +-- Maintainer : generics@haskell.org +-- Stability : experimental +-- Portability : non-portable (local universal quantification) +-- +-- Convenience alias for "Data.Generics". +-- +----------------------------------------------------------------------------- + +module Generics.SYB (module Data.Generics) where + +import Data.Generics diff --git a/src/Generics/SYB/Aliases.hs b/src/Generics/SYB/Aliases.hs new file mode 100644 --- /dev/null +++ b/src/Generics/SYB/Aliases.hs @@ -0,0 +1,17 @@ +----------------------------------------------------------------------------- +-- | +-- Module : Generics.SYB.Aliases +-- Copyright : (c) The University of Glasgow, CWI 2001--2004 +-- License : BSD-style (see the LICENSE file) +-- +-- Maintainer : generics@haskell.org +-- Stability : experimental +-- Portability : non-portable (local universal quantification) +-- +-- Convenience alias for "Data.Generics.Aliases". +-- +----------------------------------------------------------------------------- + +module Generics.SYB.Aliases (module Data.Generics.Aliases) where + +import Data.Generics.Aliases diff --git a/src/Generics/SYB/Basics.hs b/src/Generics/SYB/Basics.hs new file mode 100644 --- /dev/null +++ b/src/Generics/SYB/Basics.hs @@ -0,0 +1,17 @@ +----------------------------------------------------------------------------- +-- | +-- Module : Generics.SYB.Basics +-- Copyright : (c) The University of Glasgow, CWI 2001--2004 +-- License : BSD-style (see the LICENSE file) +-- +-- Maintainer : generics@haskell.org +-- Stability : experimental +-- Portability : non-portable (local universal quantification) +-- +-- Convenience alias for "Data.Generics.Basics". +-- +----------------------------------------------------------------------------- + +module Generics.SYB.Basics (module Data.Generics.Basics) where + +import Data.Generics.Basics diff --git a/src/Generics/SYB/Builders.hs b/src/Generics/SYB/Builders.hs new file mode 100644 --- /dev/null +++ b/src/Generics/SYB/Builders.hs @@ -0,0 +1,17 @@ +----------------------------------------------------------------------------- +-- | +-- Module : Generics.SYB.Builders +-- Copyright : (c) The University of Glasgow, CWI 2001--2004 +-- License : BSD-style (see the LICENSE file) +-- +-- Maintainer : generics@haskell.org +-- Stability : experimental +-- Portability : non-portable (local universal quantification) +-- +-- Convenience alias for "Data.Generics.Builders". +-- +----------------------------------------------------------------------------- + +module Generics.SYB.Builders (module Data.Generics.Builders) where + +import Data.Generics.Builders diff --git a/src/Generics/SYB/Instances.hs b/src/Generics/SYB/Instances.hs new file mode 100644 --- /dev/null +++ b/src/Generics/SYB/Instances.hs @@ -0,0 +1,17 @@ +----------------------------------------------------------------------------- +-- | +-- Module : Generics.SYB.Instances +-- Copyright : (c) The University of Glasgow, CWI 2001--2004 +-- License : BSD-style (see the LICENSE file) +-- +-- Maintainer : generics@haskell.org +-- Stability : experimental +-- Portability : non-portable (local universal quantification) +-- +-- Convenience alias for "Data.Generics.Instances". +-- +----------------------------------------------------------------------------- + +module Generics.SYB.Instances () where + +import Data.Generics.Instances () diff --git a/src/Generics/SYB/Schemes.hs b/src/Generics/SYB/Schemes.hs new file mode 100644 --- /dev/null +++ b/src/Generics/SYB/Schemes.hs @@ -0,0 +1,17 @@ +----------------------------------------------------------------------------- +-- | +-- Module : Generics.SYB.Schemes +-- Copyright : (c) The University of Glasgow, CWI 2001--2004 +-- License : BSD-style (see the LICENSE file) +-- +-- Maintainer : generics@haskell.org +-- Stability : experimental +-- Portability : non-portable (local universal quantification) +-- +-- Convenience alias for "Data.Generics.Schemes". +-- +----------------------------------------------------------------------------- + +module Generics.SYB.Schemes (module Data.Generics.Schemes) where + +import Data.Generics.Schemes diff --git a/src/Generics/SYB/Text.hs b/src/Generics/SYB/Text.hs new file mode 100644 --- /dev/null +++ b/src/Generics/SYB/Text.hs @@ -0,0 +1,17 @@ +----------------------------------------------------------------------------- +-- | +-- Module : Generics.SYB.Text +-- Copyright : (c) The University of Glasgow, CWI 2001--2004 +-- License : BSD-style (see the LICENSE file) +-- +-- Maintainer : generics@haskell.org +-- Stability : experimental +-- Portability : non-portable (local universal quantification) +-- +-- Convenience alias for "Data.Generics.Text". +-- +----------------------------------------------------------------------------- + +module Generics.SYB.Text (module Data.Generics.Text) where + +import Data.Generics.Text diff --git a/src/Generics/SYB/Twins.hs b/src/Generics/SYB/Twins.hs new file mode 100644 --- /dev/null +++ b/src/Generics/SYB/Twins.hs @@ -0,0 +1,17 @@ +----------------------------------------------------------------------------- +-- | +-- Module : Generics.SYB.Twins +-- Copyright : (c) The University of Glasgow, CWI 2001--2004 +-- License : BSD-style (see the LICENSE file) +-- +-- Maintainer : generics@haskell.org +-- Stability : experimental +-- Portability : non-portable (local universal quantification) +-- +-- Convenience alias for "Data.Generics.Twins". +-- +----------------------------------------------------------------------------- + +module Generics.SYB.Twins (module Data.Generics.Twins) where + +import Data.Generics.Twins diff --git a/syb.cabal b/syb.cabal --- a/syb.cabal +++ b/syb.cabal @@ -1,11 +1,12 @@ -name: syb -version: 0.1.0.3 -license: BSD3 -license-file: LICENSE -author: Ralf Lämmel, Simon Peyton Jones -maintainer: generics@haskell.org -homepage: http://www.cs.uu.nl/wiki/GenericProgramming/SYB -synopsis: Scrap Your Boilerplate +name: syb +version: 0.2 +license: BSD3 +license-file: LICENSE +author: Ralf Lammel, Simon Peyton Jones +maintainer: generics@haskell.org +homepage: http://www.cs.uu.nl/wiki/GenericProgramming/SYB +bug-reports: http://code.google.com/p/scrapyourboilerplate/issues/list +synopsis: Scrap Your Boilerplate description: This package contains the generics system described in the /Scrap Your Boilerplate/ papers (see ). @@ -15,24 +16,37 @@ category: Generics stability: provisional -build-type: Simple -cabal-version: >= 1.2.1 +build-type: Custom +cabal-version: >= 1.6 tested-with: GHC == 6.10.4, GHC == 6.12.1 +extra-source-files: tests/*.hs + Library { hs-source-dirs: src - + build-depends: base >= 4.0 && < 4.3 exposed-modules: Data.Generics, Data.Generics.Basics, Data.Generics.Instances, Data.Generics.Aliases, Data.Generics.Schemes, Data.Generics.Text, - Data.Generics.Twins + Data.Generics.Twins, + Data.Generics.Builders, + + Generics.SYB, + Generics.SYB.Basics, + Generics.SYB.Instances, + Generics.SYB.Aliases, + Generics.SYB.Schemes, + Generics.SYB.Text, + Generics.SYB.Twins, + Generics.SYB.Builders - build-depends: base >= 4.0 && < 4.3 extensions: CPP, Rank2Types, ScopedTypeVariables + if impl(ghc < 6.12) ghc-options: -package-name syb + ghc-options: -Wall } diff --git a/tests/Bits.hs b/tests/Bits.hs new file mode 100644 --- /dev/null +++ b/tests/Bits.hs @@ -0,0 +1,214 @@ +{-# OPTIONS -fglasgow-exts #-} + +module Bits (tests) where + +{- + +This test exercices some oldies of generic programming, namely +encoding terms as bit streams and decoding these bit streams in turn +to obtain terms again. (This sort of function might actually be useful +for serialisation and sending companies and other terms over the +internet.) + +Here is how it works. + +A constuctor is encoded as a bit stream. To this end, we encode the +index of the constructor as a binary number of a fixed length taking +into account the maximum index for the type at hand. (Similarly, we +could view the list of constructors as a binary tree, and then encode +a constructor as the path to the constructor in this tree.) If there +is just a single constructor, as for newtypes, for example, then the +computed bit stream is empty. + +Otherwise we just recurse into subterms. + +Well, we need to handle basic datatypes in a special way. We observe +such basic datatypes by testing the maximum index to be 0 for the +datatype at hand. An efficient encoding should be tuned per basic +datatype. The following solution is generic, but it wastes space. +That is, we turn the basic value into a string relying on the general +Data API. This string can now be encoded by first converting it into a +list of bit streams at the term level, which can then be easily +encoded as a single bit stream (because lists and bits can be +encoded). + +-} + +import Test.HUnit + +import Data.Generics +import Data.Char +import Maybe +import Monad +import CompanyDatatypes + + + +----------------------------------------------------------------------------- + + + +-- | We need bits and bit streams. +data Bit = Zero | One deriving (Show, Eq, Typeable, Data) +type Bin = [Bit] + + + +----------------------------------------------------------------------------- + + + +-- Compute length of bit stream for a natural +lengthNat :: Int -> Int +lengthNat x = ceiling (logBase 2 (fromIntegral (x + 1))) + + +-- Encode a natural as a bit stream +varNat2bin :: Int -> Bin +varNat2bin 0 = [] +varNat2bin x = + ( ( if even x then Zero else One ) + : varNat2bin (x `div` 2) + ) + + +-- Encode a natural as a bit stream of fixed length +fixedNat2bin :: Int -> Int -> Bin +fixedNat2bin 0 0 = [] +fixedNat2bin p x | p>0 = + ( ( if even x then Zero else One ) + : fixedNat2bin (p - 1) (x `div` 2) + ) + + +-- Decode a natural +bin2nat :: Bin -> Int +bin2nat [] = 0 +bin2nat (Zero : bs) = 2 * (bin2nat bs) +bin2nat (One : bs) = 2 * (bin2nat bs) + 1 + + + +----------------------------------------------------------------------------- + + + +-- | Generically map terms to bit streams +showBin :: Data t => t -> Bin + +showBin t + = if isAlgType myDataType + then con2bin ++ concat (gmapQ showBin t) + else showBin base + + where + + -- The datatype for introspection + myDataType = dataTypeOf t + + -- Obtain the maximum index for the type at hand + max :: Int + max = maxConstrIndex myDataType + + -- Obtain the index for the constructor at hand + idx :: Int + idx = constrIndex (toConstr t) + + -- Map basic values to strings, then to lists of bit streams + base = map (varNat2bin . ord) (showConstr (toConstr t)) + + -- Map constructors to bit streams of fixed length + con2bin = fixedNat2bin (lengthNat (max - 1)) (idx - 1) + + +----------------------------------------------------------------------------- + + + +-- | A monad on bit streams +data ReadB a = ReadB (Bin -> (Maybe a, Bin)) +unReadB (ReadB f) = f + + +-- It's a monad. +instance Monad ReadB where + return a = ReadB (\bs -> (Just a, bs)) + (ReadB c) >>= f = ReadB (\bs -> case c bs of + (Just a, bs') -> unReadB (f a) bs' + (Nothing, bs') -> (Nothing, bs') + ) + + +-- It's a bit monad with 0 and +. +instance MonadPlus ReadB where + mzero = ReadB (\bs -> (Nothing, bs)) + (ReadB f) `mplus` (ReadB g) = ReadB (\bs -> case f bs of + (Just a, bs') -> (Just a, bs') + (Nothing, _) -> g bs + ) + + +-- Read a few bits +readB :: Int -> ReadB Bin +readB x = ReadB (\bs -> if length bs >= x + then (Just (take x bs), drop x bs) + else (Nothing, bs) + ) + + + +----------------------------------------------------------------------------- + + + +-- | Generically map bit streams to terms +readBin :: Data t => ReadB t +readBin = result + where + + -- The worker, which we also use as type argument + result = if isAlgType myDataType + + then do bin <- readB (lengthNat (max - 1)) + fromConstrM readBin (bin2con bin) + + else do str <- readBin + con <- str2con (map (chr . bin2nat) str) + return (fromConstr con) + + -- Determine result type + myDataType = dataTypeOf (getArg result) + where + getArg :: ReadB a -> a + getArg = undefined + + -- Obtain the maximum index for the type at hand + max :: Int + max = maxConstrIndex myDataType + + -- Convert a bit stream into a constructor + bin2con :: Bin -> Constr + bin2con bin = indexConstr myDataType ((bin2nat bin) + 1) + + -- Convert string to constructor; could fail + str2con :: String -> ReadB Constr + str2con = maybe mzero return + . readConstr myDataType + + + +----------------------------------------------------------------------------- + + + +tests = ( showBin True + , ( showBin [True] + , ( showBin (1::Int) + , ( showBin "1" + , ( showBin genCom + , ( geq genCom genCom' + )))))) ~=? output + where + genCom' = fromJust (fst (unReadB readBin (showBin genCom))) :: Company + +output = 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diff --git a/tests/Builders.hs b/tests/Builders.hs new file mode 100644 --- /dev/null +++ b/tests/Builders.hs @@ -0,0 +1,20 @@ +{-# OPTIONS -fglasgow-exts #-} + +module Builders (tests) where + +-- Testing Data.Generics.Builders functionality + +import Test.HUnit + +import Data.Data +import Data.Generics.Builders + + +-- Main function for testing +tests = ( constrs :: [Maybe Int] + , constrs :: [String] + , constrs :: [Either Int Float] + , constrs :: [((), Integer)] + ) ~=? output + +output = ([Nothing,Just 0],["","\NUL"],[Left 0,Right 0.0],[((),0)]) diff --git a/tests/CompanyDatatypes.hs b/tests/CompanyDatatypes.hs new file mode 100644 --- /dev/null +++ b/tests/CompanyDatatypes.hs @@ -0,0 +1,39 @@ +{-# OPTIONS -fglasgow-exts #-} + +module CompanyDatatypes where + +import Data.Generics hiding (Unit) + +-- The organisational structure of a company + +data Company = C [Dept] deriving (Eq, Show, Typeable, Data) +data Dept = D Name Manager [Unit] deriving (Eq, Show, Typeable, Data) +data Unit = PU Employee | DU Dept deriving (Eq, Show, Typeable, Data) +data Employee = E Person Salary deriving (Eq, Show, Typeable, Data) +data Person = P Name Address deriving (Eq, Show, Typeable, Data) +data Salary = S Float deriving (Eq, Show, Typeable, Data) +type Manager = Employee +type Name = String +type Address = String + +-- An illustrative company +genCom :: Company +genCom = C [D "Research" laemmel [PU joost, PU marlow], + D "Strategy" blair []] + +-- A typo for the sake of testing equality; +-- (cf. lammel vs. laemmel) +genCom' :: Company +genCom' = C [D "Research" lammel [PU joost, PU marlow], + D "Strategy" blair []] + +lammel, laemmel, joost, blair :: Employee +lammel = E (P "Lammel" "Amsterdam") (S 8000) +laemmel = E (P "Laemmel" "Amsterdam") (S 8000) +joost = E (P "Joost" "Amsterdam") (S 1000) +marlow = E (P "Marlow" "Cambridge") (S 2000) +blair = E (P "Blair" "London") (S 100000) + +-- Some more test data +person1 = P "Lazy" "Home" +dept1 = D "Useless" (E person1 undefined) [] diff --git a/tests/Datatype.hs b/tests/Datatype.hs new file mode 100644 --- /dev/null +++ b/tests/Datatype.hs @@ -0,0 +1,35 @@ +{-# OPTIONS -fglasgow-exts #-} + +-- These are simple tests to observe (data)type representations. +module Datatype (tests) where + +import Test.HUnit + +import Data.Tree +import Data.Generics + +-- A simple polymorphic datatype +data Data a => + MyDataType a = MyDataType a + deriving (Typeable, Data) + + +-- Some terms and corresponding type representations +myTerm = undefined :: MyDataType Int +myTypeRep = typeOf myTerm -- type representation in Typeable +myTyCon = typeRepTyCon myTypeRep -- type constructor via Typeable +myDataType = dataTypeOf myTerm -- datatype representation in Data +myString1 = tyConString myTyCon -- type constructor via Typeable +myString2 = dataTypeName myDataType -- type constructor via Data + +-- Main function for testing +tests = show ( myTypeRep + , ( myDataType + , ( tyconModule myString1 + , ( tyconUQname myString1 + , ( tyconModule myString2 + , ( tyconUQname myString2 + )))))) + ~=? output + +output = "(Datatype.MyDataType Int,(DataType {tycon = \"Datatype.MyDataType\", datarep = AlgRep [MyDataType]},(\"Datatype\",(\"MyDataType\",(\"Datatype\",\"MyDataType\")))))" diff --git a/tests/Encode.hs b/tests/Encode.hs new file mode 100644 --- /dev/null +++ b/tests/Encode.hs @@ -0,0 +1,81 @@ +{-# OPTIONS -fglasgow-exts #-} + +-- A bit more test code for the 2nd boilerplate paper. +-- These are downscaled versions of library functionality or real test cases. +-- We just wanted to typecheck the fragments as shown in the paper. + +module Encode () where + +import Data.Generics + +data Bit = Zero | One + +------------------------------------------------------------------------------ +-- Sec. 3.2 + +data2bits :: Data a => a -> [Bit] +data2bits t = encodeCon (dataTypeOf t) (toConstr t) + ++ concat (gmapQ data2bits t) + +-- The encoder for constructors +encodeCon :: DataType -> Constr -> [Bit] +encodeCon ty con = natToBin (max-1) (idx-1) + where + max = maxConstrIndex ty + idx = constrIndex con + + +natToBin :: Int -> Int -> [Bit] +natToBin = undefined + +------------------------------------------------------------------------------ +-- Sec. 3.3 + +data State -- Abstract +initState :: State +encodeCon' :: DataType -> Constr + -> State -> (State, [Bit]) + +initState = undefined +encodeCon' = undefined + +data2bits' :: Data a => a -> [Bit] +data2bits' t = snd (show_bin t initState) + +show_bin :: Data a => a -> State -> (State, [Bit]) +show_bin t st = (st2, con_bits ++ args_bits) + where + (st1, con_bits) = encodeCon' (dataTypeOf t) + (toConstr t) st + (st2, args_bits) = foldr do_arg (st1,[]) + enc_args + + enc_args :: [State -> (State,[Bit])] + enc_args = gmapQ show_bin t + + do_arg fn (st,bits) = (st', bits' ++ bits) + where + (st', bits') = fn st + + +------------------------------------------------------------------------------ +-- Sec. 3.3 cont'd + +data EncM a -- The encoder monad +instance Monad EncM + where + return = undefined + c >>= f = undefined + +runEnc :: EncM () -> [Bit] +emitCon :: DataType -> Constr -> EncM () + +runEnc = undefined +emitCon = undefined + +data2bits'' :: Data a => a -> [Bit] +data2bits'' t = runEnc (emit t) + +emit :: Data a => a -> EncM () +emit t = do { emitCon (dataTypeOf t) (toConstr t) + ; sequence_ (gmapQ emit t) } diff --git a/tests/Ext.hs b/tests/Ext.hs new file mode 100644 --- /dev/null +++ b/tests/Ext.hs @@ -0,0 +1,30 @@ +{-# OPTIONS -fglasgow-exts #-} + +module Ext () where + +-- There were typos in these definitions in the ICFP 2004 paper. + +import Data.Generics + +extQ fn spec_fn arg + = case gcast (Q spec_fn) of + Just (Q spec_fn') -> spec_fn' arg + Nothing -> fn arg + +newtype Q r a = Q (a -> r) + +extT fn spec_fn arg + = case gcast (T spec_fn) of + Just (T spec_fn') -> spec_fn' arg + Nothing -> fn arg + +newtype T a = T (a -> a) + +extM :: (Typeable a, Typeable b) + => (a -> m a) -> (b -> m b) -> (a -> m a) +extM fn spec_fn + = case gcast (M spec_fn) of + Just (M spec_fn') -> spec_fn' + Nothing -> fn + +newtype M m a = M (a -> m a) diff --git a/tests/Ext1.hs b/tests/Ext1.hs new file mode 100644 --- /dev/null +++ b/tests/Ext1.hs @@ -0,0 +1,124 @@ +{-# OPTIONS -fglasgow-exts #-} + +module Ext1 (tests) where + +{- + +This example records some experiments with polymorphic datatypes. + +-} + +import Test.HUnit + +import Data.Generics +import GHC.Base + + +-- Unsafe coerce +unsafeCoerce :: a -> b +unsafeCoerce = unsafeCoerce# + + +-- Handy type constructors +newtype ID x = ID { unID :: x } +newtype CONST c a = CONST { unCONST :: c } + + +-- Extension of a query with a para. poly. list case +extListQ' :: Data d + => (d -> q) + -> (forall d. [d] -> q) + -> d -> q +extListQ' def ext d = + if isList d + then ext (unsafeCoerce d) + else def d + + +-- Test extListQ' +foo1 :: Data d => d -> Int +foo1 = const 0 `extListQ'` length +t1 = foo1 True -- should count as 0 +t2 = foo1 [True,True] -- should count as 2 + + +-- Infeasible extension of a query with a data-polymorphic list case +extListQ'' :: Data d + => (d -> q) + -> (forall d. Data d => [d] -> q) + -> d -> q +extListQ'' def ext d = + if isList d + then undefined -- hard to avoid an ambiguous type + else def d + + +-- Test extListQ from Data.Generics.Aliases +foo2 :: Data a => a -> Int +foo2 = const 0 `ext1Q` list + where + list :: Data a => [a] -> Int + list l = foldr (+) 0 $ map glength l + +t3 = foo2 (True,True) -- should count as 0 +t4 = foo2 [(True,True),(True,True)] -- should count as 2+2=4 + + +-- Customisation for lists without type cast +foo3 :: Data a => a -> Int +foo3 x = if isList x + then foldr (+) 0 $ gmapListQ glength x + else 0 + +t5 = foo3 (True,True) -- should count as 0 +t6 = foo3 [(True,True),(True,True)] -- should count as 2+2=4 + + +-- Test for list datatype +isList :: Data a => a -> Bool +isList x = typeRepTyCon (typeOf x) == + typeRepTyCon (typeOf (undefined::[()])) + + +-- Test for nil +isNil :: Data a => a -> Bool +isNil x = toConstr x == toConstr ([]::[()]) + + +-- Test for cons +isCons :: Data a => a -> Bool +isCons x = toConstr x == toConstr (():[]) + + +-- gmapQ for polymorphic lists +gmapListQ :: forall a q. Data a => (forall a. Data a => a -> q) -> a -> [q] +gmapListQ f x = + if not $ isList x + then error "gmapListQ" + else if isNil x + then [] + else if isCons x + then ( gmapQi 0 f x : gmapQi 1 (gmapListQ f) x ) + else error "gmapListQ" + + +-- Build nil +mkNil :: Data a => a +mkNil = fromConstr $ toConstr ([]::[()]) + + +-- Build cons +mkCons :: Data a => a +mkCons = fromConstr $ toConstr ((undefined:undefined)::[()]) + + +-- Main function for testing +tests = ( t1 + , ( t2 + , ( t3 + , ( t4 + , ( t5 + , ( t6 + )))))) ~=? output + +output = (0,(2,(0,(4,(0,4))))) diff --git a/tests/FoldTree.hs b/tests/FoldTree.hs new file mode 100644 --- /dev/null +++ b/tests/FoldTree.hs @@ -0,0 +1,63 @@ +{-# OPTIONS -fglasgow-exts #-} + +{- + +A very, very simple example: "extract all Ints from a tree of Ints". +The text book approach is to write a generalised fold for that. One +can also turn the Tree datatype into functorial style and then write a +Functor instance for the functorial datatype including a definition of +fmap. (The original Tree datatype can be related to the functorial +version by the usual injection and projection.) + +You can scrap all such boilerplate by using a traversal scheme based +on gmap combinators as illustrated below. To get it a little more +interesting, we use a datatype Tree with not just a case for leafs and +fork trees, but we also add a case for trees with a weight. + +For completeness' sake, we mention that the fmap/generalised fold +approach differs from the gmap approach in some details. Most notably, +the gmap approach does not generally facilitate the identification of +term components that relate to the type parameter of a parameterised +datatype. The consequence of this is illustrated below as well. +Sec. 6.3 in "Scrap Your Boilerplate ..." discusses such `type +distinctions' as well. + +-} + +module FoldTree (tests) where + +import Test.HUnit + +-- Enable "ScrapYourBoilerplate" +import Data.Generics + + +-- A parameterised datatype for binary trees with data at the leafs +data (Data a, Data w) => + Tree a w = Leaf a + | Fork (Tree a w) (Tree a w) + | WithWeight (Tree a w) w + deriving (Typeable, Data) + + +-- A typical tree +mytree :: Tree Int Int +mytree = Fork (WithWeight (Leaf 42) 1) + (WithWeight (Fork (Leaf 88) (Leaf 37)) 2) + + +-- Print everything like an Int in mytree +-- In fact, we show two attempts: +-- 1. print really just everything like an Int +-- 2. print everything wrapped with Leaf +-- So (1.) confuses leafs and weights whereas (2.) does not. +-- +tests = show ( listify (\(_::Int) -> True) mytree + , everything (++) ([] `mkQ` fromLeaf) mytree + ) ~=? output + where + fromLeaf :: Tree Int Int -> [Int] + fromLeaf (Leaf x) = [x] + fromLeaf _ = [] + +output = "([42,1,88,37,2],[42,88,37])" diff --git a/tests/FreeNames.hs b/tests/FreeNames.hs new file mode 100644 --- /dev/null +++ b/tests/FreeNames.hs @@ -0,0 +1,120 @@ +{-# OPTIONS -fglasgow-exts #-} + +module FreeNames (tests) where + +{- + +This example illustrates the kind of traversals that naturally show up +in language processing. That is, the free names (say, variables) are +derived for a given program fragment. To this end, we need several +worker functions that extract declaring and referencing occurrences +from given program fragments; see "decsExpr", "decsEqua", +etc. below. Then, we need a traversal "freeNames" that traverses over +the program fragment in a bottom-up manner so that free names from +subterms do not escape to the top when corresponding declarations are +provided. The "freeNames" algorithm uses set operations "union" and +"//" to compute sets of free names from the declared and referenced +names of the root term and free names of the immediate subterms. + +Contributed by Ralf Laemmel, ralf@cwi.nl + +-} + +import Test.HUnit + +import Data.Generics +import Data.List + +data System = S [Function] deriving (Typeable, Data) + +data Function = F Name [Equation] deriving (Typeable, Data) + +data Equation = E [Pattern] Expression System deriving (Typeable, Data) + +data Pattern = PVar Name + | PTerm Name [Pattern] deriving (Typeable, Data) + +data Expression = Var Name + | App Expression Expression + | Lambda Name Expression deriving (Typeable, Data) + +type Name = String + +-- A little sample program + +sys1 = S [f1,f2] +f1 = F "f1" [e11] +f2 = F "f2" [e21,e22] +e11 = E [] (Var "id") (S []) +e21 = E [ PTerm "C" [ PVar "x" ] ] (Var "x") (S []) +e22 = E [] (Var "id") (S []) + + +-- Names declared in an expression +decsExpr :: Expression -> [Name] +decsExpr (Lambda n _) = [n] +decsExpr _ = [] + +-- Names declared in an equation +decsEqua :: Equation -> [Name] +decsEqua (E ps _ _) = everything union ([] `mkQ` pvar) ps + where + pvar (PVar n) = [n] + pvar _ = [] + +-- Names declared in a system +decsSyst :: System -> [Name] +decsSyst (S l) = nub $ map (\(F n _) -> n) l + +-- Names referenced in an expression +refsExpr :: Expression -> [Name] +refsExpr (Var n) = [n] + +-- Names referenced in an equation +refsEqua :: Equation -> [Name] +refsEqua (E ps _ _) = everything union ([] `mkQ` pterm) ps + where + pterm (PTerm n _) = [n] + pterm _ = [] + +-- Combine the above type-specific cases to obtain +-- generic functions that find declared and referenced names +-- +decsFun :: Data a => a -> [Name] +decsFun = const [] `extQ` decsExpr `extQ` decsEqua `extQ` decsSyst + +refsFun :: Data a => a -> [Name] +refsFun = const [] `extQ` refsExpr `extQ` refsEqua + + + +{- + +Free name analysis: Take the union of free names obtained from the +immediate subterms (via gmapQ) and the names being referred to at the +root of the present term, but subtract all the names that are declared +at the root. + +-} + +freeNames :: Data a => a -> [Name] +freeNames x = ( (refsFun x) + `union` + (nub . concat . gmapQ freeNames) x + ) + \\ + decsFun x + +{- + +Print the free names for the sample program sys1; see module +FunDatatypes.hs. This should print the list ["id","C"] because the +"Prelude" function "id" is used in the sample program, and also the +term constructor "C" occurs in a pattern; we assume a language without +explicit datatype declarations ;-) + +-} + +tests = freeNames sys1 ~=? output + +output = ["id","C"] diff --git a/tests/GEq.hs b/tests/GEq.hs new file mode 100644 --- /dev/null +++ b/tests/GEq.hs @@ -0,0 +1,21 @@ +{-# OPTIONS -fglasgow-exts #-} + +module GEq (tests) where + +{- + +This test exercices GENERIC read, show, and eq for the company +datatypes which we use a lot. The output of the program should be +"True" which means that "gread" reads what "gshow" shows while the +read term is equal to the original term in terms of "geq". + +-} + +import Test.HUnit + +import Data.Generics +import CompanyDatatypes + +tests = ( geq genCom genCom + , geq genCom genCom' + ) ~=? (True,False) diff --git a/tests/GMapQAssoc.hs b/tests/GMapQAssoc.hs new file mode 100644 --- /dev/null +++ b/tests/GMapQAssoc.hs @@ -0,0 +1,68 @@ +{-# OPTIONS -fglasgow-exts #-} + +module GMapQAssoc (tests) where + +{- + +This example demonstrates the inadequacy of an apparently simpler +variation on gmapQ. To this end, let us first recall a few facts. +Firstly, function application (including constructor application) is +left-associative. This is the reason why we had preferred our generic +fold to be left-associative too. (In "The Sketch Of a Polymorphic +Symphony" you can find a right-associative generic fold.) Secondly, +lists are right-associative. Because of these inverse associativities +queries for the synthesis of lists require some extra effort to +reflect the left-to-right of immediate subterms in the queried list. +In the module Data.Generics, we solve the problem by a common +higher-order trick, that is, we do not cons lists during folding but +we pass functions on lists starting from the identity function and +passing [] to the resulting function. The following example +illustrates that we get indeed an undesirable right-to-left order if +we just apply the simple constant datatype constructor CONST instead +of the higher-order trick. + +Contributed by Ralf Laemmel, ralf@cwi.nl + +-} + +import Test.HUnit + +import Data.Generics + + +-- The plain constant type constructor +newtype CONST x y = CONST x +unCONST (CONST x) = x + + +-- A variation on the gmapQ combinator using CONST and not Q +gmapQ' :: Data a => (forall a. Data a => a -> u) -> a -> [u] +gmapQ' f = unCONST . gfoldl f' z + where + f' r a = CONST (f a : unCONST r) + z = const (CONST []) + + +-- A trivial datatype used for this test case +data IntTree = Leaf Int | Fork IntTree IntTree + deriving (Typeable, Data) + + +-- Select int if faced with a leaf +leaf (Leaf i) = [i] +leaf _ = [] + + +-- A test term +term = Fork (Leaf 1) (Leaf 2) + + +-- Process test term +-- gmapQ gives left-to-right order +-- gmapQ' gives right-to-left order +-- +tests = show ( gmapQ ([] `mkQ` leaf) term + , gmapQ' ([] `mkQ` leaf) term + ) ~=? output + +output = show ([[1],[2]],[[2],[1]]) diff --git a/tests/GShow.hs b/tests/GShow.hs new file mode 100644 --- /dev/null +++ b/tests/GShow.hs @@ -0,0 +1,52 @@ +{-# OPTIONS -fglasgow-exts #-} + +module GShow (tests) where + +{- + +The generic show example from the 2nd boilerplate paper. +(There were some typos in the ICFP 2004 paper.) +Also check out Data.Generics.Text. + +-} + +import Test.HUnit + +import Data.Generics hiding (gshow) +import Prelude hiding (showString) + + +gshow :: Data a => a -> String +gshow = gshow_help `extQ` showString + +gshow_help :: Data a => a -> String +gshow_help t + = "(" + ++ showConstr (toConstr t) + ++ concat (intersperse " " (gmapQ gshow t)) + ++ ")" + +showString :: String -> String +showString s = "\"" ++ concat (map escape s) ++ "\"" + where + escape '\n' = "\\n" + escape other_char = [other_char] + +gshowList :: Data b => [b] -> String +gshowList xs + = "[" ++ concat (intersperse "," (map gshow xs)) ++ "]" + +gshow' :: Data a => a -> String +gshow' = gshow_help `ext1Q` gshowList + `extQ` showString + +intersperse :: a -> [a] -> [a] +intersperse _ [] = [] +intersperse x [e] = [e] +intersperse x (e:es) = (e:(x:intersperse x es)) + +tests = ( gshow' "foo" + , gshow' [True,False] + ) ~=? output + +output = ("\"foo\"","[(True),(False)]") diff --git a/tests/GShow2.hs b/tests/GShow2.hs new file mode 100644 --- /dev/null +++ b/tests/GShow2.hs @@ -0,0 +1,47 @@ +{-# OPTIONS -fglasgow-exts #-} + +module GShow2 (tests) where + +{- + +This test exercices GENERIC show for the infamous company datatypes. The +output of the program should be some representation of the infamous +"genCom" company. + +-} + +import Test.HUnit + +import Data.Generics +import CompanyDatatypes + +tests = gshow genCom ~=? output + +{- + +Here is another exercise: +The following function gshow' is a completely generic variation on gshow. +It would print strings as follows: + +*Main> gshow' "abc" +"((:) ('a') ((:) ('b') ((:) ('c') ([]))))" + +The original gshow does a better job because it is customised for strings: + +*Main> gshow "foo" +"\"foo\"" + +In fact, this is what Haskell's normal show would also do: + +*Main> show "foo" +"\"foo\"" + +-} + +gshow' :: Data a => a -> String +gshow' t = "(" + ++ showConstr (toConstr t) + ++ concat (gmapQ ((++) " " . gshow') t) + ++ ")" + +output = "(C ((:) (D \"Research\" (E (P \"Laemmel\" \"Amsterdam\") (S (8000.0))) ((:) (PU (E (P \"Joost\" \"Amsterdam\") (S (1000.0)))) ((:) (PU (E (P \"Marlow\" \"Cambridge\") (S (2000.0)))) ([])))) ((:) (D \"Strategy\" (E (P \"Blair\" \"London\") (S (100000.0))) ([])) ([]))))" diff --git a/tests/GZip.hs b/tests/GZip.hs new file mode 100644 --- /dev/null +++ b/tests/GZip.hs @@ -0,0 +1,46 @@ +{-# OPTIONS -fglasgow-exts #-} + +module GZip (tests) where + +{- + +This test illustrates zipping for the company datatypes which we use a +lot. We process two companies that happen to agree on the overall +shape but differ in the salaries in a few positions. So whenever we +encounter salaries we take the maximum of the two. + +-} + +import Test.HUnit + +import Data.Generics +import CompanyDatatypes + +-- The main function which prints the result of zipping +tests = gzip (\x y -> mkTT maxS x y) genCom1 genCom2 ~=? output + -- NB: the argument has to be eta-expanded to match + -- the type of gzip's argument type, which is + -- GenericQ (GenericM Maybe) + where + + -- Variations on the show case company "genCom" + genCom1 = everywhere (mkT (double "Joost")) genCom + genCom2 = everywhere (mkT (double "Marlow")) genCom + double x (E p@(P y _) (S s)) | x == y = E p (S (2*s)) + double _ e = e + + -- Sum up two salaries + maxS (S x) (S y) = S (max x y) + + -- Make a two-arguments, generic function transformer + mkTT :: (Typeable a, Typeable b, Typeable c) + => (a -> a -> a) -> b -> c -> Maybe c + mkTT (f::a -> a -> a) x y = + case (cast x,cast y) of + (Just (x'::a),Just (y'::a)) -> cast (f x' y') + _ -> Nothing + +output = Just (C [D "Research" (E (P "Laemmel" "Amsterdam") (S 8000.0)) + [PU (E (P "Joost" "Amsterdam") (S 2000.0)) + ,PU (E (P "Marlow" "Cambridge") (S 4000.0))] + ,D "Strategy" (E (P "Blair" "London") (S 100000.0)) []]) diff --git a/tests/GenUpTo.hs b/tests/GenUpTo.hs new file mode 100644 --- /dev/null +++ b/tests/GenUpTo.hs @@ -0,0 +1,94 @@ +{-# OPTIONS -fglasgow-exts #-} + +module GenUpTo (tests) where + +{- + +This example illustrate test-set generation, +namely all terms of a given depth are generated. + +-} + +import Test.HUnit + +import Data.Generics + + +{- + +The following datatypes comprise the abstract syntax of a simple +imperative language. Some provisions are such that the discussion +of test-set generation is simplified. In particular, we do not +consider anything but monomorphic *data*types --- no primitive +types, no tuples, ... + +-} + +data Prog = Prog Dec Stat + deriving (Show, Eq, Typeable, Data) + +data Dec = Nodec + | Ondec Id Type + | Manydecs Dec Dec + deriving (Show, Eq, Typeable, Data) + +data Id = A | B + deriving (Show, Eq, Typeable, Data) + +data Type = Int | Bool + deriving (Show, Eq, Typeable, Data) + +data Stat = Noop + | Assign Id Exp + | Seq Stat Stat + deriving (Show, Eq, Typeable, Data) + +data Exp = Zero + | Succ Exp + deriving (Show, Eq, Typeable, Data) + + +-- Generate all terms of a given depth +genUpTo :: Data a => Int -> [a] +genUpTo 0 = [] +genUpTo d = result + where + -- Getting hold of the result (type) + result = concat (map recurse cons) + + -- Retrieve constructors of the requested type + cons :: [Constr] + cons = dataTypeConstrs (dataTypeOf (head result)) + + -- Find all terms headed by a specific Constr + recurse :: Data a => Constr -> [a] + recurse con = gmapM (\_ -> genUpTo (d-1)) + (fromConstr con) + + -- We could also deal with primitive types easily. + -- Then we had to use cons' instead of cons. + -- + cons' :: [Constr] + cons' = case dataTypeRep ty of + AlgRep cons -> cons + IntRep -> [mkIntegralConstr ty 0] + FloatRep -> [mkIntegralConstr ty 0] + CharRep -> [mkCharConstr ty 'x'] + where + ty = dataTypeOf (head result) + + +-- For silly tests +data T0 = T0 T1 T2 T3 deriving (Show, Eq, Typeable, Data) +data T1 = T1a | T1b deriving (Show, Eq, Typeable, Data) +data T2 = T2a | T2b deriving (Show, Eq, Typeable, Data) +data T3 = T3a | T3b deriving (Show, Eq, Typeable, Data) + +tests = ( genUpTo 0 :: [Id] + , ( genUpTo 1 :: [Id] + , ( genUpTo 2 :: [Id] + , ( genUpTo 2 :: [T0] + , ( genUpTo 3 :: [Prog] + ))))) ~=? output + +output = ([],([A,B],([A,B],([T0 T1a T2a T3a,T0 T1a T2a T3b,T0 T1a T2b T3a,T0 T1a T2b T3b,T0 T1b T2a T3a,T0 T1b T2a T3b,T0 T1b T2b T3a,T0 T1b T2b T3b],[Prog Nodec Noop,Prog Nodec (Assign A Zero),Prog Nodec (Assign B Zero),Prog Nodec (Seq Noop Noop),Prog (Ondec A Int) Noop,Prog (Ondec A Int) (Assign A Zero),Prog (Ondec A Int) (Assign B Zero),Prog (Ondec A Int) (Seq Noop Noop),Prog (Ondec A Bool) Noop,Prog (Ondec A Bool) (Assign A Zero),Prog (Ondec A Bool) (Assign B Zero),Prog (Ondec A Bool) (Seq Noop Noop),Prog (Ondec B Int) Noop,Prog (Ondec B Int) (Assign A Zero),Prog (Ondec B Int) (Assign B Zero),Prog (Ondec B Int) (Seq Noop Noop),Prog (Ondec B Bool) Noop,Prog (Ondec B Bool) (Assign A Zero),Prog (Ondec B Bool) (Assign B Zero),Prog (Ondec B Bool) (Seq Noop Noop),Prog (Manydecs Nodec Nodec) Noop,Prog (Manydecs Nodec Nodec) (Assign A Zero),Prog (Manydecs Nodec Nodec) (Assign B Zero),Prog (Manydecs Nodec Nodec) (Seq Noop Noop)])))) diff --git a/tests/GetC.hs b/tests/GetC.hs new file mode 100644 --- /dev/null +++ b/tests/GetC.hs @@ -0,0 +1,121 @@ +{-# OPTIONS -fglasgow-exts #-} +{-# LANGUAGE OverlappingInstances, UndecidableInstances #-} + +module GetC (tests) where + +import Test.HUnit + +{- + +Ralf Laemmel, 5 November 2004 + +Joe Stoy suggested the idiom to test for the outermost constructor. + +Given is a term t +and a constructor f (say the empty constructor application). + +isC f t returns True if the outermost constructor of t is f. +isC f t returns False otherwise. +Modulo type checking, i.e., the data type of f and t must be the same. +If not, we want to see a type error, of course. + +-} + +import Data.Typeable -- to cast t's subterms, which will be reused for f. +import Data.Generics -- to access t's subterms and constructors. + + +-- Some silly data types +data T1 = T1a Int String | T1b String Int deriving (Typeable, Data) +data T2 = T2a Int Int | T2b String String deriving (Typeable, Data) +data T3 = T3! Int deriving (Typeable, Data) + + +-- Test cases +tests = show [ isC T1a (T1a 1 "foo") -- typechecks, returns True + , isC T1a (T1b "foo" 1) -- typechecks, returns False + , isC T3 (T3 42)] -- works for strict data too + ~=? output +-- err = show $ isC T2b (T1b "foo" 1) -- must not typecheck + +output = show [True,False,True] + +-- +-- We look at a datum a. +-- We look at a constructor function f. +-- The class GetT checks that f constructs data of type a. +-- The class GetC computes maybe the constructor ... +-- ... if the subterms of the datum at hand fit for f. +-- Finally we compare the constructors. +-- + +isC :: (Data a, GetT f a, GetC f) => f -> a -> Bool +isC f t = maybe False ((==) (toConstr t)) con + where + kids = gmapQ ExTypeable t -- homogenify subterms in list for reuse + con = getC f kids -- compute constructor from constructor application + + +-- +-- We prepare for a list of kids using existential envelopes. +-- We could also just operate on TypeReps for non-strict datatypes. +-- + +data ExTypeable = forall a. Typeable a => ExTypeable a +unExTypeable (ExTypeable a) = cast a + + +-- +-- Compute the result type of a function type. +-- Beware: the TypeUnify constraint causes headache. +-- We can't have GetT t t because the FD will be violated then. +-- We can't omit the FD because unresolvable overlapping will hold then. +-- + +class GetT f t | f -> t -- FD is optional +instance GetT g t => GetT (x -> g) t +instance TypeUnify t t' => GetT t t' + + +-- +-- Obtain the constructor if term can be completed +-- + +class GetC f + where + getC :: f -> [ExTypeable] -> Maybe Constr + +instance (Typeable x, GetC g) => GetC (x -> g) + where + getC _ [] = Nothing + getC (f::x->g) (h:t) + = + do + (x::x) <- unExTypeable h + getC (f x) t + +instance Data t => GetC t + where + getC y [] = Just $ toConstr y + getC _ (_:_) = Nothing + + +-- +-- Type unification; we could try this: +-- class TypeUnify a b | a -> b, b -> a +-- instance TypeUnify a a +-- +-- However, if the instance is placed in the present module, +-- then type improvement would inline this instance. Sigh!!! +-- +-- So we need type unification with type improvement blocker +-- The following solution works with GHC for ages. +-- Other solutions; see the HList paper. +-- + +class TypeUnify a b | a -> b, b -> a +class TypeUnify' x a b | x a -> b, x b -> a +class TypeUnify'' x a b | x a -> b, x b -> a +instance TypeUnify' () a b => TypeUnify a b +instance TypeUnify'' x a b => TypeUnify' x a b +instance TypeUnify'' () a a diff --git a/tests/Gread.hs b/tests/Gread.hs new file mode 100644 --- /dev/null +++ b/tests/Gread.hs @@ -0,0 +1,45 @@ +{-# OPTIONS -fglasgow-exts #-} + +module GRead (tests) where + +{- + +The following examples achieve branch coverage for the various +productions in the definition of gread. Also, negative test cases are +provided; see str2 and str3. Also, the potential of heading or +trailing spaces as well incomplete parsing of the input is exercised; +see str5. + +-} + +import Test.HUnit + +import Data.Generics + +str1 = "(True)" -- reads fine as a Bool +str2 = "(Treu)" -- invalid constructor +str3 = "True" -- lacks parentheses +str4 = "(1)" -- could be an Int +str5 = "( 2 ) ..." -- could be an Int with some trailing left-over +str6 = "([])" -- test empty list +str7 = "((:)" ++ " " ++ str4 ++ " " ++ str6 ++ ")" + +tests = show ( ( [ gread str1, + gread str2, + gread str3 + ] + , [ gread str4, + gread str5 + ] + , [ gread str6, + gread str7 + ] + ) + :: ( [[(Bool, String)]] + , [[(Int, String)]] + , [[([Int], String)]] + ) + ) ~=? output + +output = show + ([[(True,"")],[],[]],[[(1,"")],[(2,"...")]],[[([],"")],[([1],"")]]) diff --git a/tests/Gread2.hs b/tests/Gread2.hs new file mode 100644 --- /dev/null +++ b/tests/Gread2.hs @@ -0,0 +1,66 @@ +{-# OPTIONS -fglasgow-exts #-} + +module GRead2 () where + +{- + +For the discussion in the 2nd boilerplate paper, +we favour some simplified generic read, which is checked to compile. +For the full/real story see Data.Generics.Text. + +-} + +import Data.Generics + +gread :: Data a => String -> Maybe a +gread input = runDec input readM + +-- The decoder monad +newtype DecM a = D (String -> Maybe (String, a)) + +instance Monad DecM where + return a = D (\s -> Just (s,a)) + (D m) >>= k = D (\s -> + case m s of + Nothing -> Nothing + Just (s1,a) -> let D n = k a + in n s1) + +runDec :: String -> DecM a -> Maybe a +runDec input (D m) = do (_,x) <- m input + return x + +parseConstr :: DataType -> DecM Constr +parseConstr ty = D (\s -> + match s (dataTypeConstrs ty)) + where + match :: String -> [Constr] + -> Maybe (String, Constr) + match _ [] = Nothing + match input (con:cons) + | take n input == showConstr con + = Just (drop n input, con) + | otherwise + = match input cons + where + n = length (showConstr con) + + +readM :: forall a. Data a => DecM a +readM = read + where + read :: DecM a + read = do { let val = argOf read + ; let ty = dataTypeOf val + ; constr <- parseConstr ty + ; let con::a = fromConstr constr + ; gmapM (\_ -> readM) con } + +argOf :: c a -> a +argOf = undefined + +yareadM :: forall a. Data a => DecM a +yareadM = do { let ty = dataTypeOf (undefined::a) + ; constr <- parseConstr ty + ; let con::a = fromConstr constr + ; gmapM (\_ -> yareadM) con } diff --git a/tests/HList.hs b/tests/HList.hs new file mode 100644 --- /dev/null +++ b/tests/HList.hs @@ -0,0 +1,62 @@ +{-# OPTIONS -fglasgow-exts #-} + +module HList (tests) where + +{- + +This module illustrates heterogeneously typed lists. + +-} + +import Test.HUnit + +import Data.Typeable + + +-- Heterogeneously typed lists +type HList = [DontKnow] + +data DontKnow = forall a. Typeable a => DontKnow a + +-- The empty list +initHList :: HList +initHList = [] + +-- Add an entry +addHList :: Typeable a => a -> HList -> HList +addHList a l = (DontKnow a:l) + +-- Test for an empty list +nullHList :: HList -> Bool +nullHList = null + +-- Retrieve head by type case +headHList :: Typeable a => HList -> Maybe a +headHList [] = Nothing +headHList (DontKnow a:_) = cast a + +-- Retrieve tail by type case +tailHList :: HList -> HList +tailHList = tail + +-- Access per index; starts at 1 +nth1HList :: Typeable a => Int -> HList -> Maybe a +nth1HList i l = case (l !! (i-1)) of (DontKnow a) -> cast a + + +---------------------------------------------------------------------------- + +-- A demo list +mylist = addHList (1::Int) $ + addHList (True::Bool) $ + addHList ("42"::String) $ + initHList + +-- Main function for testing +tests = ( show (nth1HList 1 mylist :: Maybe Int) -- shows Just 1 + , ( show (nth1HList 1 mylist :: Maybe Bool) -- shows Nothing + , ( show (nth1HList 2 mylist :: Maybe Bool) -- shows Just True + , ( show (nth1HList 3 mylist :: Maybe String) -- shows Just "42" + )))) ~=? output + +output = ("Just 1",("Nothing",("Just True","Just \"42\""))) diff --git a/tests/HOPat.hs b/tests/HOPat.hs new file mode 100644 --- /dev/null +++ b/tests/HOPat.hs @@ -0,0 +1,67 @@ +{-# OPTIONS -fglasgow-exts #-} + +module HOPat (tests) where + +{- + +This module is in reply to an email by C. Barry Jay +received on March 15, and handled within hours. CBJ +raises the very interesting issue of higher-order patterns. +It turns out that some form of it is readily covered in +our setting. + +-} + +import Test.HUnit + +import Data.Generics + + +-- Sample datatypes +data T1 = T1a Int | T1b Float + deriving (Show, Eq, Typeable, Data) +data T2 = T2a T1 T2 | T2b + deriving (Show, Eq, Typeable, Data) + +-- Eliminate a constructor if feasible +elim' :: (Data y, Data x) => Constr -> y -> Maybe x +elim' c y = if toConstr y == c + then unwrap y + else Nothing + + +-- Unwrap a term; Return its single component +unwrap :: (Data y, Data x) => y -> Maybe x +unwrap y = case gmapQ (Nothing `mkQ` Just) y of + [Just x] -> Just x + _ -> Nothing + + +-- Eliminate a constructor if feasible; 2nd try +elim :: forall x y. (Data y, Data x) => (x -> y) -> y -> Maybe x +elim c y = elim' (toConstr (c (undefined::x))) y + + +-- Visit a data structure +visitor :: (Data x, Data y, Data z) + => (x -> y) -> (x -> x) -> z -> z +visitor c f = everywhere (mkT g) + where + g y = case elim c y of + Just x -> c (f x) + Nothing -> y + + +-- Main function for testing +tests = ( ( elim' (toConstr t1a) t1a) :: Maybe Int + , ( (elim' (toConstr t1a) t1b) :: Maybe Int + , ( (elim T1a t1a) :: Maybe Int + , ( (elim T1a t1b) :: Maybe Int + , ( (visitor T1a ((+) 46) t2) :: T2 + ))))) ~=? output + where + t1a = T1a 42 + t1b = T1b 3.14 + t2 = T2a t1a (T2a t1a T2b) + +output = (Just 42,(Nothing,(Just 42,(Nothing,T2a (T1a 88) (T2a (T1a 88) T2b))))) diff --git a/tests/Labels.hs b/tests/Labels.hs new file mode 100644 --- /dev/null +++ b/tests/Labels.hs @@ -0,0 +1,30 @@ +{-# OPTIONS -fglasgow-exts #-} + +module Labels (tests) where + +-- This module tests availability of field labels. + +import Test.HUnit + +import Data.Generics + +-- A datatype without labels +data NoLabels = NoLabels Int Float + deriving (Typeable, Data) + +-- A datatype with labels +data YesLabels = YesLabels { myint :: Int + , myfloat :: Float + } + deriving (Typeable, Data) + +-- Test terms +noLabels = NoLabels 42 3.14 +yesLabels = YesLabels 42 3.14 + +-- Main function for testing +tests = ( constrFields $ toConstr noLabels + , constrFields $ toConstr yesLabels + ) ~=? output + +output = ([],["myint","myfloat"]) diff --git a/tests/LocalQuantors.hs b/tests/LocalQuantors.hs new file mode 100644 --- /dev/null +++ b/tests/LocalQuantors.hs @@ -0,0 +1,21 @@ +{-# OPTIONS -fglasgow-exts #-} + +module LocalQuantors () where + +-- A datatype with a locally quantified component +-- Seems to be too polymorphic to descend into structure! +-- Largely irrelevant?! + +import Data.Generics + +data Test = Test (GenericT) deriving Typeable + +instance Data Test + where + gfoldl _ z x = z x -- folding without descent + toConstr (Test _) = testConstr + gunfold _ _ = error "gunfold" + dataTypeOf _ = testDataType + +testConstr = mkConstr testDataType "Test" [] Prefix +testDataType = mkDataType "Main.Test" [testConstr] diff --git a/tests/Main.hs b/tests/Main.hs new file mode 100644 --- /dev/null +++ b/tests/Main.hs @@ -0,0 +1,82 @@ + +module Main where + +import Test.HUnit +import System.Exit + +import qualified Bits +import qualified Builders +import qualified Datatype +import qualified Ext1 +import qualified FoldTree +import qualified FreeNames +import qualified GEq +import qualified GMapQAssoc +import qualified GRead +import qualified GShow +import qualified GShow2 +import qualified GZip +import qualified GenUpTo +import qualified GetC +import qualified HList +import qualified HOPat +import qualified Labels +import qualified Newtype +import qualified Paradise +import qualified Perm +import qualified Reify +import qualified Strings +import qualified Tree +import qualified Twin +import qualified Typeable +import qualified Typecase1 +import qualified Typecase2 +import qualified Where +import qualified XML + +import qualified Encode -- no tests, should compile +import qualified Ext -- no tests, should compile +import qualified GRead2 -- no tests, should compile +import qualified LocalQuantors -- no tests, should compile +import qualified NestedDatatypes -- no tests, should compile +import qualified Polymatch -- no tests, should compile + + +tests = + "All" ~: [ Datatype.tests + , FoldTree.tests + , GetC.tests + , GMapQAssoc.tests + , GRead.tests + , GShow.tests + , GShow2.tests + , HList.tests + , HOPat.tests + , Labels.tests + , Newtype.tests + , Perm.tests + , Twin.tests + , Typeable.tests + , Typecase1.tests + , Typecase2.tests + , Where.tests + , XML.tests + , Tree.tests + , Strings.tests + , Reify.tests + , Paradise.tests + , GZip.tests + , GEq.tests + , GenUpTo.tests + , FreeNames.tests + , Ext1.tests + , Bits.tests + , Builders.tests + ] + +main = do + putStrLn "Running tests for syb..." + counts <- runTestTT tests + if (failures counts > 0) + then exitFailure + else exitSuccess diff --git a/tests/NestedDatatypes.hs b/tests/NestedDatatypes.hs new file mode 100644 --- /dev/null +++ b/tests/NestedDatatypes.hs @@ -0,0 +1,52 @@ +{-# OPTIONS -fglasgow-exts #-} +{-# LANGUAGE UndecidableInstances #-} + +module NestedDatatypes () where + +{- + +We provide an illustrative ScrapYourBoilerplate example for a nested +datatype. For clarity, we do not derive the Typeable and Data +instances by the deriving mechanism but we show the intended +definitions. The overall conclusion is that nested datatypes do not +pose any challenge for the ScrapYourBoilerplate scheme. Well, this is +maybe not quite true because it seems like we need to allow +undecidable instances. + +-} + +import Data.Dynamic +import Data.Generics + + +-- A nested datatype +data Nest a = Box a | Wrap (Nest [a]) + + +-- The representation of the type constructor +nestTc = mkTyCon "Nest" + + +-- The Typeable instance for the nested datatype +instance Typeable1 Nest + where + typeOf1 n = mkTyConApp nestTc [] + + +-- The Data instance for the nested datatype +instance (Data a, Data [a]) => Data (Nest a) + where + gfoldl k z (Box a) = z Box `k` a + gfoldl k z (Wrap w) = z Wrap `k` w + gmapT f (Box a) = Box (f a) + gmapT f (Wrap w) = Wrap (f w) + toConstr (Box _) = boxConstr + toConstr (Wrap _) = wrapConstr + gunfold k z c = case constrIndex c of + 1 -> k (z Box) + 2 -> k (z Wrap) + dataTypeOf _ = nestDataType + +boxConstr = mkConstr nestDataType "Box" [] Prefix +wrapConstr = mkConstr nestDataType "Wrap" [] Prefix +nestDataType = mkDataType "Main.Nest" [boxConstr,wrapConstr] diff --git a/tests/Newtype.hs b/tests/Newtype.hs new file mode 100644 --- /dev/null +++ b/tests/Newtype.hs @@ -0,0 +1,15 @@ +{-# OPTIONS -fglasgow-exts #-} + +module Newtype (tests) where + +-- The type of a newtype should treat the newtype as opaque + +import Test.HUnit + +import Data.Generics + +newtype T = MkT Int deriving( Typeable ) + +tests = show (typeOf (undefined :: T)) ~=? output + +output = "Newtype.T" diff --git a/tests/Paradise.hs b/tests/Paradise.hs new file mode 100644 --- /dev/null +++ b/tests/Paradise.hs @@ -0,0 +1,29 @@ +{-# OPTIONS -fglasgow-exts #-} + +module Paradise (tests) where + +{- + +This test runs the infamous PARADISE benchmark, +which is the HELLO WORLD example of generic programming, +i.e., the "increase salary" function is applied to +a typical company just as shown in the boilerplate paper. + +-} + +import Test.HUnit + +import Data.Generics +import CompanyDatatypes + +-- Increase salary by percentage +increase :: Float -> Company -> Company +increase k = everywhere (mkT (incS k)) + +-- "interesting" code for increase +incS :: Float -> Salary -> Salary +incS k (S s) = S (s * (1+k)) + +tests = increase 0.1 genCom ~=? output + +output = C [D "Research" (E (P "Laemmel" "Amsterdam") (S 8800.0)) [PU (E (P "Joost" "Amsterdam") (S 1100.0)),PU (E (P "Marlow" "Cambridge") (S 2200.0))],D "Strategy" (E (P "Blair" "London") (S 110000.0)) []] diff --git a/tests/Perm.hs b/tests/Perm.hs new file mode 100644 --- /dev/null +++ b/tests/Perm.hs @@ -0,0 +1,127 @@ +{-# OPTIONS -fglasgow-exts #-} + +module Perm (tests) where + +{- + +This module illustrates permutation phrases. +Disclaimer: this is a perhaps naive, certainly undebugged example. + +-} + +import Test.HUnit + +import Control.Monad +import Data.Generics + +--------------------------------------------------------------------------- +-- We want to read terms of type T3 regardless of the order T1 and T2. +--------------------------------------------------------------------------- + +data T1 = T1 deriving (Show, Eq, Typeable, Data) +data T2 = T2 deriving (Show, Eq, Typeable, Data) +data T3 = T3 T1 T2 deriving (Show, Eq, Typeable, Data) + + +--------------------------------------------------------------------------- +-- A silly monad that we use to read lists of constructor strings. +--------------------------------------------------------------------------- + +-- Type constructor +newtype ReadT a = ReadT { unReadT :: [String] -> Maybe ([String],a) } + + + +-- Run a computation +runReadT x y = case unReadT x y of + Just ([],y) -> Just y + _ -> Nothing + +-- Read one string +readT :: ReadT String +readT = ReadT (\x -> if null x + then Nothing + else Just (tail x, head x) + ) + +-- ReadT is a monad! +instance Monad ReadT where + return x = ReadT (\y -> Just (y,x)) + c >>= f = ReadT (\x -> case unReadT c x of + Nothing -> Nothing + Just (x', a) -> unReadT (f a) x' + ) + +-- ReadT also accommodates mzero and mplus! +instance MonadPlus ReadT where + mzero = ReadT (const Nothing) + f `mplus` g = ReadT (\x -> case unReadT f x of + Nothing -> unReadT g x + y -> y + ) + + +--------------------------------------------------------------------------- +-- A helper type to appeal to predicative type system. +--------------------------------------------------------------------------- + +newtype GenM = GenM { unGenM :: forall a. Data a => a -> ReadT a } + + +--------------------------------------------------------------------------- +-- The function that reads and copes with all permutations. +--------------------------------------------------------------------------- + +buildT :: forall a. Data a => ReadT a +buildT = result + + where + result = do str <- readT + con <- string2constr str + ske <- return $ fromConstr con + fs <- return $ gmapQ buildT' ske + perm [] fs ske + + -- Determine type of data to be constructed + myType = myTypeOf result + where + myTypeOf :: forall a. ReadT a -> a + myTypeOf = undefined + + -- Turn string into constructor + string2constr str = maybe mzero + return + (readConstr (dataTypeOf myType) str) + + -- Specialise buildT per kid type + buildT' :: forall a. Data a => a -> GenM + buildT' (_::a) = GenM (const mzero `extM` const (buildT::ReadT a)) + + -- The permutation exploration function + perm :: forall a. Data a => [GenM] -> [GenM] -> a -> ReadT a + perm [] [] a = return a + perm fs [] a = perm [] fs a + perm fs (f:fs') a = ( + do a' <- gmapMo (unGenM f) a + perm fs fs' a' + ) + `mplus` + ( + do guard (not (null fs')) + perm (f:fs) fs' a + ) + + +--------------------------------------------------------------------------- +-- The main function for testing +--------------------------------------------------------------------------- + +tests = + ( runReadT buildT ["T1"] :: Maybe T1 -- should parse fine + , ( runReadT buildT ["T2"] :: Maybe T2 -- should parse fine + , ( runReadT buildT ["T3","T1","T2"] :: Maybe T3 -- should parse fine + , ( runReadT buildT ["T3","T2","T1"] :: Maybe T3 -- should parse fine + , ( runReadT buildT ["T3","T2","T2"] :: Maybe T3 -- should fail + ))))) ~=? output + +output = (Just T1,(Just T2,(Just (T3 T1 T2),(Just (T3 T1 T2),Nothing)))) diff --git a/tests/Polymatch.hs b/tests/Polymatch.hs new file mode 100644 --- /dev/null +++ b/tests/Polymatch.hs @@ -0,0 +1,70 @@ +{-# OPTIONS -fglasgow-exts #-} + +module Polymatch () where + + +import Data.Typeable +import Data.Generics + + +-- Representation of kids +kids x = gmapQ Kid x -- get all kids +type Kids = [Kid] +data Kid = forall k. Typeable k => Kid k + + +-- Build term from a list of kids and the constructor +fromConstrL :: Data a => Kids -> Constr -> Maybe a +fromConstrL l = unIDL . gunfold k z + where + z c = IDL (Just c) l + k (IDL Nothing _) = IDL Nothing undefined + k (IDL (Just f) (Kid x:l)) = IDL f' l + where + f' = case cast x of + (Just x') -> Just (f x') + _ -> Nothing + + +-- Helper datatype +data IDL x = IDL (Maybe x) Kids +unIDL (IDL mx _) = mx + + +-- Two sample datatypes +data A = A String deriving (Read, Show, Eq, Data, Typeable) +data B = B String deriving (Read, Show, Eq, Data, Typeable) + + +-- Mediate between two "left-equal" Either types +f :: (Data a, Data b, Show a, Read b) + => (a->b) -> Either String a -> Either String b + +f g (Right a) = Right $ g a -- conversion really needed +-- f g (Left s) = Left s -- unappreciated conversion +-- f g s = s -- doesn't typecheck +-- f g s = deep_rebuild s -- too expensive +f g s = just (shallow_rebuild s) -- perhaps this is Ok? + + +-- Get rid of maybies +just = maybe (error "tried, but failed.") id + + +-- Just mentioned for completeness' sake +deep_rebuild :: (Show a, Read b) => a -> b +deep_rebuild = read . show + + +-- For the record: it's possible. +shallow_rebuild :: (Data a, Data b) => a -> Maybe b +shallow_rebuild a = b + where + b = fromConstrL (kids a) constr + constr = indexConstr (dataTypeOf b) (constrIndex (toConstr a)) + + +-- Test cases +a2b (A s) = B s -- silly conversion +t1 = f a2b (Left "x") -- prints Left "x" +t2 = f a2b (Right (A "y")) -- prints Right (B "y") diff --git a/tests/Reify.hs b/tests/Reify.hs new file mode 100644 --- /dev/null +++ b/tests/Reify.hs @@ -0,0 +1,413 @@ +{-# OPTIONS -fglasgow-exts #-} + +module Reify (tests) where + +{- + +The following examples illustrate the reification facilities for type +structure. Most notably, we generate shallow terms using the depth of +types and constructors as means to steer the generation. + +-} + +import Test.HUnit + +import Data.Maybe +import Data.Generics +import Control.Monad.State +import CompanyDatatypes + + + +------------------------------------------------------------------------------ +-- +-- Encoding types as values; some other way. +-- +------------------------------------------------------------------------------ + +{- + +This group provides a style of encoding types as values and using +them. This style is seen as an alternative to the pragmatic style used +in Data.Typeable.typeOf and elsewhere, i.e., simply use an "undefined" +to denote a type argument. This pragmatic style suffers from lack +of robustness: one feels tempted to pattern match on undefineds. +Maybe Data.Typeable.typeOf etc. should be rewritten accordingly. + +-} + + +-- | Type as values to stipulate use of undefineds +type TypeVal a = a -> () + + +-- | The value that denotes a type +typeVal :: TypeVal a +typeVal = const () + + +-- | Test for type equivalence +sameType :: (Typeable a, Typeable b) => TypeVal a -> TypeVal b -> Bool +sameType tva tvb = typeOf (type2val tva) == + typeOf (type2val tvb) + + +-- | Map a value to its type +val2type :: a -> TypeVal a +val2type _ = typeVal + + +-- | Stipulate this idiom! +type2val :: TypeVal a -> a +type2val _ = undefined + + +-- | Constrain a type +withType :: a -> TypeVal a -> a +withType x _ = x + + +-- | The argument type of a function +argType :: (a -> b) -> TypeVal a +argType _ = typeVal + + +-- | The result type of a function +resType :: (a -> b) -> TypeVal b +resType _ = typeVal + + +-- | The parameter type of type constructor +paraType :: t a -> TypeVal a +paraType _ = typeVal + + +-- Type functions, +-- i.e., functions mapping types to values +-- +type TypeFun a r = TypeVal a -> r + + + +-- Generic type functions, +-- i.e., functions mapping types to values +-- +type GTypeFun r = forall a. Data a => TypeFun a r + + + +-- | Extend a type function +extType :: (Data a, Typeable r) => GTypeFun r -> TypeFun a r -> GTypeFun r +extType f x = maybe f id (cast x) + + + +------------------------------------------------------------------------------ +-- +-- Mapping operators to map over type structure +-- +------------------------------------------------------------------------------ + + +-- | Query all constructors of a given type + +gmapType :: ([(Constr,r')] -> r) + -> GTypeFun (Constr -> r') + -> GTypeFun r + +gmapType (o::[(Constr,r')] -> r) f (t::TypeVal a) + = + o $ zip cons query + + where + + -- All constructors of the given type + cons :: [Constr] + cons = if isAlgType $ dataTypeOf $ type2val t + then dataTypeConstrs $ dataTypeOf $ type2val t + else [] + + -- Query constructors + query :: [r'] + query = map (f t) cons + + +-- | Query all subterm types of a given constructor + +gmapConstr :: ([r] -> r') + -> GTypeFun r + -> GTypeFun (Constr -> r') + +gmapConstr (o::[r] -> r') f (t::TypeVal a) c + = + o $ query + + where + + -- Term for the given constructor + term :: a + term = fromConstr c + + -- Query subterm types + query :: [r] + query = gmapQ (f . val2type) term + + +-- | Compute arity of a given constructor +constrArity :: GTypeFun (Constr -> Int) +constrArity t c = glength $ withType (fromConstr c) t + + +-- | Query all immediate subterm types of a given type +gmapSubtermTypes :: (Data a, Typeable r) + => (r -> r -> r) -> r -> GTypeFun r -> TypeVal a -> r +gmapSubtermTypes o (r::r) f (t::TypeVal a) + = + reduce (concat (map (gmapQ (query . val2type)) terms)) + (GTypeFun' f) + + where + + -- All constructors of the given type + cons :: [Constr] + cons = if isAlgType $ dataTypeOf $ type2val t + then dataTypeConstrs $ dataTypeOf $ type2val t + else [] + + -- Terms for all constructors + terms :: [a] + terms = map fromConstr cons + + -- Query a subterm type + query :: Data b => TypeVal b -> GTypeFun' r -> (r,GTypeFun' r) + query t f = (unGTypeFun' f t, GTypeFun' (disable t (unGTypeFun' f))) + + -- Constant out given type + disable :: Data b => TypeVal b -> GTypeFun r -> GTypeFun r + disable (t::TypeVal b) f = f `extType` \(_::TypeVal b) -> r + + -- Reduce all subterm types + reduce :: [GTypeFun' r -> (r,GTypeFun' r)] -> GTypeFun' r -> r + reduce [] _ = r + reduce (xy:z) g = fst (xy g) `o` reduce z (snd (xy g)) + + +-- First-class polymorphic variation on GTypeFun +newtype GTypeFun' r = GTypeFun' (GTypeFun r) +unGTypeFun' (GTypeFun' f) = f + + +-- | Query all immediate subterm types. +-- There is an extra argument to \"constant out\" the type at hand. +-- This can be used to avoid cycles. + +gmapSubtermTypesConst :: (Data a, Typeable r) + => (r -> r -> r) + -> r + -> GTypeFun r + -> TypeVal a + -> r +gmapSubtermTypesConst o (r::r) f (t::TypeVal a) + = + gmapSubtermTypes o r f' t + where + f' :: GTypeFun r + f' = f `extType` \(_::TypeVal a) -> r + + +-- Count all distinct subterm types +gcountSubtermTypes :: Data a => TypeVal a -> Int +gcountSubtermTypes = gmapSubtermTypes (+) (0::Int) (const 1) + + +-- | A simplied variation on gmapSubtermTypes. +-- Weakness: no awareness of doubles. +-- Strength: easy to comprehend as it uses gmapType and gmapConstr. + +_gmapSubtermTypes :: (Data a, Typeable r) + => (r -> r -> r) -> r -> GTypeFun r -> TypeVal a -> r +_gmapSubtermTypes o (r::r) f + = + gmapType otype (gmapConstr oconstr f) + + where + + otype :: [(Constr,r)] -> r + otype = foldr (\x y -> snd x `o` y) r + + oconstr :: [r] -> r + oconstr = foldr o r + + +------------------------------------------------------------------------------ +-- +-- Some reifying relations on types +-- +------------------------------------------------------------------------------ + + +-- | Reachability relation on types, i.e., +-- test if nodes of type @a@ are reachable from nodes of type @b@. +-- The relation is defined to be reflexive. + +reachableType :: (Data a, Data b) => TypeVal a -> TypeVal b -> Bool +reachableType (a::TypeVal a) (b::TypeVal b) + = + or [ sameType a b + , gmapSubtermTypesConst (\x y -> or [x,y]) False (reachableType a) b + ] + + +-- | Depth of a datatype as the constructor with the minimum depth. +-- The outermost 'Nothing' denotes a type without constructors. +-- The innermost 'Nothing' denotes potentially infinite. + +depthOfType :: GTypeFun Bool -> GTypeFun (Maybe (Constr, Maybe Int)) +depthOfType p (t::TypeVal a) + = + gmapType o f t + + where + + o :: [(Constr, Maybe Int)] -> Maybe (Constr, Maybe Int) + o l = if null l then Nothing else Just (foldr1 min' l) + + f :: GTypeFun (Constr -> Maybe Int) + f = depthOfConstr p' + + -- Specific minimum operator + min' :: (Constr, Maybe Int) -> (Constr, Maybe Int) -> (Constr, Maybe Int) + min' x (_, Nothing) = x + min' (_, Nothing) x = x + min' (c, Just i) (c', Just i') | i <= i' = (c, Just i) + min' (c, Just i) (c', Just i') = (c', Just i') + + -- Updated predicate for unblocked types + p' :: GTypeFun Bool + p' = p `extType` \(_::TypeVal a) -> False + + +-- | Depth of a constructor. +-- Depth is viewed as the maximum depth of all subterm types + 1. +-- 'Nothing' denotes potentially infinite. + +depthOfConstr :: GTypeFun Bool -> GTypeFun (Constr -> Maybe Int) +depthOfConstr p (t::TypeVal a) c + = + gmapConstr o f t c + + where + + o :: [Maybe Int] -> Maybe Int + o = inc' . foldr max' (Just 0) + + f :: GTypeFun (Maybe Int) + f t' = if p t' + then + case depthOfType p t' of + Nothing -> Just 0 + Just (_, x) -> x + else Nothing + + -- Specific maximum operator + max' Nothing _ = Nothing + max' _ Nothing = Nothing + max' (Just i) (Just i') | i >= i' = Just i + max' (Just i) (Just i') = Just i' + + -- Specific increment operator + inc' Nothing = Nothing + inc' (Just i) = Just (i+1) + + +------------------------------------------------------------------------------ +-- +-- Build a shallow term +-- +------------------------------------------------------------------------------ + +shallowTerm :: (forall a. Data a => Maybe a) -> (forall b. Data b => b) +shallowTerm cust + = result + where + result :: forall b. Data b => b + -- Need a type signature here to bring 'b' into scope + result = maybe gdefault id cust + where + + -- The worker, also used for type disambiguation + gdefault :: b + gdefault = case con of + Just (con, Just _) -> fromConstrB (shallowTerm cust) con + _ -> error "no shallow term!" + + -- The type to be constructed + typeVal :: TypeVal b + typeVal = val2type gdefault + + -- The most shallow constructor if any + con :: Maybe (Constr, Maybe Int) + con = depthOfType (const True) typeVal + + + +-- For testing shallowTerm +shallowTermBase :: GenericR Maybe +shallowTermBase = Nothing + `extR` Just (1.23::Float) + `extR` Just ("foo"::String) + + + +-- Sample datatypes +data T1 = T1a deriving (Typeable, Data) -- just a constant +data T2 = T2 T1 deriving (Typeable, Data) -- little detour +data T3 = T3a T3 | T3b T2 deriving (Typeable, Data) -- recursive case +data T4 = T4 T3 T3 deriving (Typeable, Data) -- sum matters + + + +-- Sample type arguments +t0 = typeVal :: TypeVal Int +t1 = typeVal :: TypeVal T1 +t2 = typeVal :: TypeVal T2 +t3 = typeVal :: TypeVal T3 +t4 = typeVal :: TypeVal T4 +tCompany = typeVal :: TypeVal Company +tPerson = typeVal :: TypeVal Person +tEmployee = typeVal :: TypeVal Employee +tDept = typeVal :: TypeVal Dept + + + +-- Test cases +test0 = t1 `reachableType` t1 -- True +test1 = t1 `reachableType` t2 -- True +test2 = t2 `reachableType` t1 -- False +test3 = t1 `reachableType` t3 +test4 = tPerson `reachableType` tCompany +test5 = gcountSubtermTypes tPerson +test6 = gcountSubtermTypes tEmployee +test7 = gcountSubtermTypes tDept +test8 = shallowTerm shallowTermBase :: Person +test9 = shallowTerm shallowTermBase :: Employee +test10 = shallowTerm shallowTermBase :: Dept + + + +tests = ( test0 + , ( test1 + , ( test2 + , ( test3 + , ( test4 + , ( test5 + , ( test6 + , ( test7 + , ( test8 + , ( test9 + , ( test10 + ))))))))))) ~=? output + +output = (True,(True,(False,(True,(True,(1,(2,(3,(P "foo" "foo", + (E (P "foo" "foo") (S 1.23), + D "foo" (E (P "foo" "foo") (S 1.23)) [])))))))))) diff --git a/tests/Strings.hs b/tests/Strings.hs new file mode 100644 --- /dev/null +++ b/tests/Strings.hs @@ -0,0 +1,21 @@ +{-# OPTIONS -fglasgow-exts #-} + +module Strings (tests) where + +{- + +This test exercices GENERIC read, show, and eq for the company +datatypes which we use a lot. The output of the program should be +"True" which means that "gread" reads what "gshow" shows while the +read term is equal to the original term in terms of "geq". + +-} + +import Test.HUnit + +import Data.Generics +import CompanyDatatypes + +tests = (case gread (gshow genCom) of + [(x,_)] -> geq genCom x + _ -> False) ~=? True diff --git a/tests/Tree.hs b/tests/Tree.hs new file mode 100644 --- /dev/null +++ b/tests/Tree.hs @@ -0,0 +1,62 @@ +{-# OPTIONS -fglasgow-exts #-} + +module Tree (tests) where + +{- + +This example illustrates serialisation and de-serialisation, +but we replace *series* by *trees* so to say. + +-} + +import Test.HUnit + +import Control.Monad.Reader +import Data.Generics +import Data.Maybe +import Data.Tree +import CompanyDatatypes + + +-- Trealise Data to Tree +data2tree :: Data a => a -> Tree String +data2tree = gdefault `extQ` atString + where + atString (x::String) = Node x [] + gdefault x = Node (showConstr (toConstr x)) (gmapQ data2tree x) + + +-- De-trealise Tree to Data +tree2data :: Data a => Tree String -> Maybe a +tree2data = gdefault `extR` atString + where + atString (Node x []) = Just x + gdefault (Node x ts) = res + where + + -- a helper for type capture + res = maybe Nothing (kids . fromConstr) con + + -- the type to constructed + ta = fromJust res + + -- construct constructor + con = readConstr (dataTypeOf ta) x + + -- recursion per kid with accumulation + perkid ts = const (tail ts, tree2data (head ts)) + + -- recurse into kids + kids x = + do guard (glength x == length ts) + snd (gmapAccumM perkid ts x) + + +-- Main function for testing +tests = ( genCom + , ( data2tree genCom + , ( (tree2data (data2tree genCom)) :: Maybe Company + , ( Just genCom == tree2data (data2tree genCom) + )))) ~=? output + +output = (C [D "Research" (E (P "Laemmel" "Amsterdam") (S 8000.0)) [PU (E (P "Joost" "Amsterdam") (S 1000.0)),PU (E (P "Marlow" "Cambridge") (S 2000.0))],D "Strategy" (E (P "Blair" "London") (S 100000.0)) []],(Node {rootLabel = "C", subForest = [Node {rootLabel = "(:)", subForest = [Node {rootLabel = "D", subForest = [Node {rootLabel = "Research", subForest = []},Node {rootLabel = "E", subForest = [Node {rootLabel = "P", subForest = [Node {rootLabel = "Laemmel", subForest = []},Node {rootLabel = "Amsterdam", subForest = []}]},Node {rootLabel = "S", subForest = [Node {rootLabel = "8000.0", subForest = []}]}]},Node {rootLabel = "(:)", subForest = [Node {rootLabel = "PU", subForest = [Node {rootLabel = "E", subForest = [Node {rootLabel = "P", subForest = [Node {rootLabel = "Joost", subForest = []},Node {rootLabel = "Amsterdam", subForest = []}]},Node {rootLabel = "S", subForest = [Node {rootLabel = "1000.0", subForest = []}]}]}]},Node {rootLabel = "(:)", subForest = [Node {rootLabel = "PU", subForest = [Node {rootLabel = "E", subForest = [Node {rootLabel = "P", subForest = [Node {rootLabel = "Marlow", subForest = []},Node {rootLabel = "Cambridge", subForest = []}]},Node {rootLabel = "S", subForest = [Node {rootLabel = "2000.0", subForest = []}]}]}]},Node {rootLabel = "[]", subForest = []}]}]}]},Node {rootLabel = "(:)", subForest = [Node {rootLabel = "D", subForest = [Node {rootLabel = "Strategy", subForest = []},Node {rootLabel = "E", subForest = [Node {rootLabel = "P", subForest = [Node {rootLabel = "Blair", subForest = []},Node {rootLabel = "London", subForest = []}]},Node {rootLabel = "S", subForest = [Node {rootLabel = "100000.0", subForest = []}]}]},Node {rootLabel = "[]", subForest = []}]},Node {rootLabel = "[]", subForest = []}]}]}]},(Just (C [D "Research" (E (P "Laemmel" "Amsterdam") (S 8000.0)) [PU (E (P "Joost" "Amsterdam") (S 1000.0)),PU (E (P "Marlow" "Cambridge") (S 2000.0))],D "Strategy" (E (P "Blair" "London") (S 100000.0)) []]),True))) diff --git a/tests/Twin.hs b/tests/Twin.hs new file mode 100644 --- /dev/null +++ b/tests/Twin.hs @@ -0,0 +1,90 @@ +{-# OPTIONS -fglasgow-exts #-} + +module Twin (tests) where + +{- + +For the discussion in the 2nd boilerplate paper, +we favour some simplified development of twin traversal. +So the full general, stepwise story is in Data.Generics.Twin, +but the short version from the paper is turned into a test +case below. + +See the paper for an explanation. + +-} + +import Test.HUnit + +import Data.Generics hiding (GQ,gzipWithQ,geq) + +geq' :: GenericQ (GenericQ Bool) +geq' x y = toConstr x == toConstr y + && and (gzipWithQ geq' x y) + +geq :: Data a => a -> a -> Bool +geq = geq' + +newtype GQ r = GQ (GenericQ r) + +gzipWithQ :: GenericQ (GenericQ r) + -> GenericQ (GenericQ [r]) +gzipWithQ f t1 t2 + = gApplyQ (gmapQ (\x -> GQ (f x)) t1) t2 + +gApplyQ :: Data a => [GQ r] -> a -> [r] +gApplyQ qs t = reverse (snd (gfoldlQ k z t)) + where + k :: ([GQ r], [r]) -> GenericQ ([GQ r], [r]) + k (GQ q : qs, rs) child = (qs, q child : rs) + z = (qs, []) + +newtype R r x = R { unR :: r } + +gfoldlQ :: (r -> GenericQ r) + -> r + -> GenericQ r + +gfoldlQ k z t = unR (gfoldl k' z' t) + where + z' _ = R z + k' (R r) c = R (k r c) + +----------------------------------------------------------------------------- + +-- A dependently polymorphic geq +geq'' :: Data a => a -> a -> Bool +geq'' x y = toConstr x == toConstr y + && and (gzipWithQ' geq'' x y) + +-- A helper type for existentially quantified queries +data XQ r = forall a. Data a => XQ (a -> r) + +-- A dependently polymorphic gzipWithQ +gzipWithQ' :: (forall a. Data a => a -> a -> r) + -> (forall a. Data a => a -> a -> [r]) +gzipWithQ' f t1 t2 + = gApplyQ' (gmapQ (\x -> XQ (f x)) t1) t2 + +-- Apply existentially quantified queries +-- Insist on equal types! +-- +gApplyQ' :: Data a => [XQ r] -> a -> [r] +gApplyQ' qs t = reverse (snd (gfoldlQ k z t)) + where + z = (qs, []) + k :: ([XQ r], [r]) -> GenericQ ([XQ r], [r]) + k (XQ q : qs, rs) child = (qs, q' child : rs) + where + q' = error "Twin mismatch" `extQ` q + + +----------------------------------------------------------------------------- + +tests = ( geq [True,True] [True,True] + , geq [True,True] [True,False] + , geq'' [True,True] [True,True] + , geq'' [True,True] [True,False] + ) ~=? output + +output = (True,False,True,False) diff --git a/tests/Typeable.hs b/tests/Typeable.hs new file mode 100644 --- /dev/null +++ b/tests/Typeable.hs @@ -0,0 +1,19 @@ +{-# OPTIONS -fglasgow-exts #-} + +module Typeable (tests) where + +import Test.HUnit + +import Data.Typeable + +newtype Y e = Y { unY :: (e (Y e)) } + +instance Typeable1 e => Typeable (Y e) where + typeOf _ = mkTyConApp yTc [typeOf1 (undefined :: e ())] + +yTc :: TyCon +yTc = mkTyCon "Typeable.Y" + +tests = show (typeOf (undefined :: Y [])) ~=? output + +output = "Typeable.Y []" diff --git a/tests/Typecase1.hs b/tests/Typecase1.hs new file mode 100644 --- /dev/null +++ b/tests/Typecase1.hs @@ -0,0 +1,59 @@ +{-# OPTIONS -fglasgow-exts #-} + +module Typecase1 (tests) where + +{- + +This test demonstrates type case as it lives in Data.Typeable. +We define a function f that converts typeables into strings in some way. +Note: we only need Data.Typeable. Say: Dynamics are NOT involved. + +-} + +import Test.HUnit + +import Data.Typeable +import Data.Maybe + +-- Some datatype. +data MyTypeable = MyCons String deriving (Show, Typeable) + +-- +-- Some function that performs type case. +-- +f :: (Show a, Typeable a) => a -> String +f a = (maybe (maybe (maybe others + mytys (cast a) ) + float (cast a) ) + int (cast a) ) + + where + + -- do something with ints + int :: Int -> String + int a = "got an int, incremented: " ++ show (a + 1) + + -- do something with floats + float :: Float -> String + float a = "got a float, multiplied by .42: " ++ show (a * 0.42) + + -- do something with my typeables + mytys :: MyTypeable -> String + mytys a = "got a term: " ++ show a + + -- do something with all other typeables + others = "got something else: " ++ show a + + +-- +-- Test the type case +-- +tests = ( f (41::Int) + , f (88::Float) + , f (MyCons "42") + , f True) ~=? output + +output = ( "got an int, incremented: 42" + , "got a float, multiplied by .42: 36.96" + , "got a term: MyCons \"42\"" + , "got something else: True") diff --git a/tests/Typecase2.hs b/tests/Typecase2.hs new file mode 100644 --- /dev/null +++ b/tests/Typecase2.hs @@ -0,0 +1,61 @@ +{-# OPTIONS -fglasgow-exts #-} + +module Typecase2 (tests) where + +{- + +This test provides a variation on typecase1.hs. +This time, we use generic show as defined for all instances of Data. +Thereby, we get rid of the Show constraint in our functions. +So we only keep a single constraint: the one for class Data. + +-} + +import Test.HUnit + +import Data.Generics +import Data.Maybe + +-- Some datatype. +data MyData = MyCons String deriving (Typeable, Data) + +-- +-- Some function that performs type case. +-- +f :: Data a => a -> String +f a = (maybe (maybe (maybe others + mytys (cast a) ) + float (cast a) ) + int (cast a) ) + + where + + -- do something with ints + int :: Int -> String + int a = "got an int, incremented: " ++ show (a + 1) + + -- do something with floats + float :: Float -> String + float a = "got a float, multiplied by .42: " ++ show (a * 0.42) + + -- do something with my data + mytys :: MyData -> String + mytys a = "got my data: " ++ gshow a + + -- do something with all other data + others = "got something else: " ++ gshow a + + +-- +-- Test the type case +-- +tests = ( f (41::Int) + , f (88::Float) + , f (MyCons "42") + , f True) ~=? output + +output = ( "got an int, incremented: 42" + , "got a float, multiplied by .42: 36.96" + , "got my data: (MyCons \"42\")" + , "got something else: (True)") + diff --git a/tests/Where.hs b/tests/Where.hs new file mode 100644 --- /dev/null +++ b/tests/Where.hs @@ -0,0 +1,125 @@ +{-# OPTIONS -fglasgow-exts #-} + +module Where (tests) where + +{- + +This example illustrates some differences between certain traversal +schemes. To this end, we use a simple system of datatypes, and the +running example shall be to replace "T1a 42" by "T1a 88". It is our +intention to illustrate a few dimensions of designing traversals. + +1. We can decide on whether we prefer "rewrite steps" (i.e., +monomorphic functions on data) that succeed either for all input +patterns or only if the encounter a term pattern to be replaced. In +the first case, the catch-all equation of such a function describes +identity (see "stepid" below). In the second case, the catch-call +equation describes failure using the Maybe type constructor (see +"stepfail" below). As an intermediate assessment, the failure approach +is more general because it allows one to observe if a rewrite step was +meaningful or not. Often the identity approach is more convenient and +sufficient. + +2. We can now also decide on whether we want monadic or simple +traversals; recall monadic generic functions GenericM from +Data.Generics. The monad can serve for success/failure, state, +environment and others. One can now subdivide monadic traversal +schemes with respect to the question whether they simply support +monadic style of whether they even interact with the relevant +monad. The scheme "everywereM" from the library belongs to the first +category while "somewhere" belongs to the second category as it uses +the operation "mplus" of a monad with addition. So while "everywhereM" +makes very well sense without a monad --- as demonstrated by +"everywhere", the scheme "somewhere" is immediately monadic. + +3. We can now also decide on whether we want rewrite steps to succeed +for all possible subterms, at least for one subterm, exactly for one +subterm, and others. The various traversal schemes make different +assumptions in this respect. + +a) everywhere + + By its type, succeeds and requires non-failing rewrite steps. + However, we do not get any feedback on whether terms were actually + rewritten. (Say, we might have performed accidentally the identity + function on all nodes.) + +b) everywhereM + + Attempts to reach all nodes where all the sub-traversals are performed + in monadic bind-sequence. Failure of the traversal for a given subterm + implies failure of the entire traversal. Hence, the argument of + "everywhereM" should be designed in a way that it tends to succeed + except for the purpose of propagating a proper error in the sense of + violating a pre-/post-condition. For example, "mkM stepfail" should + not be passed to "everywhereM" as it will fail for all but one term + pattern; see "recovered" for a way to massage "stepfail" accordingly. + +c) somewhere + + Descends into term in a top-down manner, and stops in a given + branch when the argument succeeds for the subterm at hand. To this + end, it takes an argument that is perfectly intended to fail for + certain term patterns. Thanks to the employment of gmapF, the + traversal scheme recovers from failure when mapping over the immediate + subterms while insisting success for at least one subterm (say, branch). + This scheme is appropriate if you want to make sure that a given + rewrite step was actually used in a traversal. So failure of the + traversal would mean that the argument failed for all subterms. + +Contributed by Ralf Laemmel, ralf@cwi.nl + +-} + +import Test.HUnit + +import Data.Generics +import Control.Monad + + +-- Two mutually recursive datatypes +data T1 = T1a Int | T1b T2 deriving (Typeable, Data) +data T2 = T2 T1 deriving (Typeable, Data) + + +-- A rewrite step with identity as catch-all case +stepid (T1a 42) = T1a 88 +stepid x = x + + +-- The same rewrite step but now with failure as catch-all case +stepfail (T1a 42) = Just (T1a 88) +stepfail _ = Nothing + + +-- We can let recover potentially failing generic functions from failure; +-- this is illustrated for a generic made from stepfail via mkM. +recovered x = mkM stepfail x `mplus` Just x + + +-- A test term that comprehends a redex +term42 = T1b (T2 (T1a 42)) + + +-- A test term that does not comprehend a redex +term37 = T1b (T2 (T1a 37)) + + +-- A number of traversals +result1 = everywhere (mkT stepid) term42 -- rewrites term accordingly +result2 = everywhere (mkT stepid) term37 -- preserves term without notice +result3 = everywhereM (mkM stepfail) term42 -- fails in a harsh manner +result4 = everywhereM (mkM stepfail) term37 -- fails rather early +result5 = everywhereM recovered term37 -- preserves term without notice +result6 = somewhere (mkMp stepfail) term42 -- rewrites term accordingly +result7 = somewhere (mkMp stepfail) term37 -- fails to notice lack of redex + +tests = gshow ( result1, + ( result2, + ( result3, + ( result4, + ( result5, + ( result6, + ( result7 ))))))) ~=? output + +output = "((,) (T1b (T2 (T1a (88)))) ((,) (T1b (T2 (T1a (37)))) ((,) (Nothing) ((,) (Nothing) ((,) (Just (T1b (T2 (T1a (37))))) ((,) (Just (T1b (T2 (T1a (88))))) (Nothing)))))))" diff --git a/tests/XML.hs b/tests/XML.hs new file mode 100644 --- /dev/null +++ b/tests/XML.hs @@ -0,0 +1,195 @@ +{-# OPTIONS -fglasgow-exts #-} + +module XML (tests) where + +{- + +This example illustrates XMLish services +to trealise (say, "serialise") heterogenous +Haskell data as homogeneous tree structures +(say, XMLish elements) and vice versa. + +-} + +import Test.HUnit + +import Control.Monad +import Data.Maybe +import Data.Generics +import CompanyDatatypes + + +-- HaXml-like types for XML elements +data Element = Elem Name [Attribute] [Content] + deriving (Show, Eq, Typeable, Data) + +data Content = CElem Element + | CString Bool CharData + -- ^ bool is whether whitespace is significant + | CRef Reference + | CMisc Misc + deriving (Show, Eq, Typeable, Data) + +type CharData = String + + +-- In this simple example we disable some parts of XML +type Attribute = () +type Reference = () +type Misc = () + + +-- Trealisation +data2content :: Data a => a -> [Content] +data2content = element + `ext1Q` list + `extQ` string + `extQ` float + + where + + -- Handle an element + element x = [CElem (Elem (tyconUQname (dataTypeName (dataTypeOf x))) + [] -- no attributes + (concat (gmapQ data2content x)))] + + -- A special case for lists + list :: Data a => [a] -> [Content] + list = concat . map data2content + + -- A special case for strings + string :: String -> [Content] + string x = [CString True x] + + -- A special case for floats + float :: Float -> [Content] + float x = [CString True (show x)] + + +-- De-trealisation +content2data :: forall a. Data a => ReadX a +content2data = result + + where + + -- Case-discriminating worker + result = element + `ext1R` list + `extR` string + `extR` float + + + -- Determine type of data to be constructed + myType = myTypeOf result + where + myTypeOf :: forall a. ReadX a -> a + myTypeOf = undefined + + -- Handle an element + element = do c <- readX + case c of + (CElem (Elem x as cs)) + | as == [] -- no attributes + && x == (tyconUQname (dataTypeName (dataTypeOf myType))) + -> alts cs + _ -> mzero + + + -- A special case for lists + list :: forall a. Data a => ReadX [a] + list = ( do h <- content2data + t <- list + return (h:t) ) + `mplus` return [] + + -- Fold over all alternatives, say constructors + alts cs = foldr (mplus . recurse cs) mzero shapes + + -- Possible top-level shapes + shapes = map fromConstr consOf + + -- Retrieve all constructors of the requested type + consOf = dataTypeConstrs + $ dataTypeOf + $ myType + + -- Recurse into subterms + recurse cs x = maybe mzero + return + (runReadX (gmapM (const content2data) x) cs) + + -- A special case for strings + string :: ReadX String + string = do c <- readX + case c of + (CString _ x) -> return x + _ -> mzero + + -- A special case for floats + float :: ReadX Float + float = do c <- readX + case c of + (CString _ x) -> return (read x) + _ -> mzero + + + +----------------------------------------------------------------------------- +-- +-- An XML-hungry parser-like monad +-- +----------------------------------------------------------------------------- + +-- Type constructor +newtype ReadX a = + ReadX { unReadX :: [Content] + -> Maybe ([Content], a) } + +-- Run a computation +runReadX x y = case unReadX x y of + Just ([],y) -> Just y + _ -> Nothing + +-- Read one content particle +readX :: ReadX Content +readX = ReadX (\x -> if null x + then Nothing + else Just (tail x, head x) + ) + +-- ReadX is a monad! +instance Monad ReadX where + return x = ReadX (\y -> Just (y,x)) + c >>= f = ReadX (\x -> case unReadX c x of + Nothing -> Nothing + Just (x', a) -> unReadX (f a) x' + ) + +-- ReadX also accommodates mzero and mplus! +instance MonadPlus ReadX where + mzero = ReadX (const Nothing) + f `mplus` g = ReadX (\x -> case unReadX f x of + Nothing -> unReadX g x + y -> y + ) + + + +----------------------------------------------------------------------------- +-- +-- Main function for testing +-- +----------------------------------------------------------------------------- + +tests = ( genCom + , ( data2content genCom + , ( zigzag person1 :: Maybe Person + , ( zigzag genCom :: Maybe Company + , ( zigzag genCom == Just genCom + ))))) ~=? output + where + -- Trealise back and forth + zigzag :: Data a => a -> Maybe a + zigzag = runReadX content2data . data2content + +output = (C [D "Research" (E (P "Laemmel" "Amsterdam") (S 8000.0)) [PU (E (P "Joost" "Amsterdam") (S 1000.0)),PU (E (P "Marlow" "Cambridge") (S 2000.0))],D "Strategy" (E (P "Blair" "London") (S 100000.0)) []],([CElem (Elem "Company" [] [CElem (Elem "Dept" [] [CString True "Research",CElem (Elem "Employee" [] [CElem (Elem "Person" [] [CString True "Laemmel",CString True "Amsterdam"]),CElem (Elem "Salary" [] [CString True "8000.0"])]),CElem (Elem "Unit" [] [CElem (Elem "Employee" [] [CElem (Elem "Person" [] [CString True "Joost",CString True "Amsterdam"]),CElem (Elem "Salary" [] [CString True "1000.0"])])]),CElem (Elem "Unit" [] [CElem (Elem "Employee" [] [CElem (Elem "Person" [] [CString True "Marlow",CString True "Cambridge"]),CElem (Elem "Salary" [] [CString True "2000.0"])])])]),CElem (Elem "Dept" [] [CString True "Strategy",CElem (Elem "Employee" [] [CElem (Elem "Person" [] [CString True "Blair",CString True "London"]),CElem (Elem "Salary" [] [CString True "100000.0"])])])])],(Just (P "Lazy" "Home"),(Just (C [D "Research" (E (P "Laemmel" "Amsterdam") (S 8000.0)) [PU (E (P "Joost" "Amsterdam") (S 1000.0)),PU (E (P "Marlow" "Cambridge") (S 2000.0))],D "Strategy" (E (P "Blair" "London") (S 100000.0)) []]),True))))