Ticket #1773: Category.dpatch

New patches:

[new Control.Compositor module
Ashley Yakeley <ashley@semantic.org>**20071013074851
 
 The Compositor class is a superclass of Arrow.
] {
addfile ./Control/Compositor.hs
hunk ./Control/Applicative.hs 42
+import Control.Compositor
hunk ./Control/Applicative.hs 44
-       (Arrow(arr, (>>>), (&&&)), ArrowZero(zeroArrow), ArrowPlus((<+>)))
+       (Arrow(arr, (&&&)), ArrowZero(zeroArrow), ArrowPlus((<+>)))
hunk ./Control/Arrow.hs 28
-               (<<<), (<<^), (^<<),
+               (<<^), (^<<),
hunk ./Control/Arrow.hs 43
+import Control.Compositor
hunk ./Control/Arrow.hs 50
-infixr 1 >>>, ^>>, >>^
-infixr 1 <<<, ^<<, <<^
+infixr 1 ^>>, >>^
+infixr 1 ^<<, <<^
hunk ./Control/Arrow.hs 55
---   as well as '>>>' and 'first'.  The other combinators have sensible
+--   as well as 'first'.  The other combinators have sensible
hunk ./Control/Arrow.hs 58
-class Arrow a where
+class Compositor a => Arrow a where
hunk ./Control/Arrow.hs 69
-       -- | Left-to-right composition of arrows.
-       (>>>) :: a b c -> a c d -> a b d
-
hunk ./Control/Arrow.hs 98
+"identity"
+               arr id = identity
hunk ./Control/Arrow.hs 120
-       f >>> g = g . f
hunk ./Control/Arrow.hs 130
+instance Monad m => Compositor (Kleisli m) where
+       identity = Kleisli return
+       Kleisli f >>> Kleisli g = Kleisli (\b -> f b >>= g)
+
hunk ./Control/Arrow.hs 136
-       Kleisli f >>> Kleisli g = Kleisli (\b -> f b >>= g)
hunk ./Control/Arrow.hs 152
--- | Right-to-left composition, for a better fit with arrow notation.
-(<<<) :: Arrow a => a c d -> a b c -> a b d
-f <<< g = g >>> f
-
hunk ./Control/Compositor.hs 1
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  Control.Compositor
+-- Copyright   :  (c) Ashley Yakeley 2007
+-- License     :  BSD-style (see the LICENSE file in the distribution)
+--
+-- Maintainer  :  ashley@semantic.org
+-- Stability   :  experimental
+-- Portability :  portable
+
+module Control.Compositor where
+
+infixr 1 >>>, <<<
+
+class Compositor comp where
+       identity :: comp a a
+
+       -- | Left-to-right composition
+       (>>>) :: comp a b -> comp b c -> comp a c
+
+{-# RULES
+"identity/left"        forall p .
+               identity >>> p = p
+"identity/right"       forall p .
+               p >>> identity = p
+"association"  forall p q r .
+               (p >>> q) >>> r = p >>> (q >>> r)
+ #-}
+
+instance Compositor (->) where
+       identity = id
+       p >>> q = q . p
+
+-- | Right-to-left composition
+(<<<) :: Compositor comp => comp b c -> comp a b -> comp a c
+f <<< g = g >>> f
+
hunk ./base.cabal 72
+        Control.Compositor,
}

[new Control.Category, ghc ticket #1773
Ashley Yakeley <ashley@semantic.org>**20071029022526] {
move ./Control/Compositor.hs ./Control/Category.hs
replace ./Control/Applicative.hs [A-Za-z_0-9] Compositor Category
replace ./Control/Arrow.hs [A-Za-z_0-9] Compositor Category
replace ./Control/Category.hs [A-Za-z_0-9] Compositor Category
replace ./Control/Category.hs [A-Za-z_0-9] comp cat
replace ./base.cabal [A-Za-z_0-9] Compositor Category
hunk ./Control/Applicative.hs 38
-#ifdef __HADDOCK__
-import Prelude
-#endif
+import Prelude hiding (id,(.))
hunk ./Control/Arrow.hs 39
-import Prelude
+import Prelude hiding (id,(.))
hunk ./Control/Arrow.hs 99
-               arr id = identity
+               arr id = id
hunk ./Control/Arrow.hs 101
-               arr f >>> arr g = arr (f >>> g)
+               (arr f) . (arr g) = arr (f . g)
hunk ./Control/Arrow.hs 111
-               first f >>> first g = first (f >>> g)
+               (first f) . (first g) = first (f . g)
hunk ./Control/Arrow.hs 113
-               second f >>> second g = second (f >>> g)
+               (second f) . (second g) = second (f . g)
hunk ./Control/Arrow.hs 131
-       identity = Kleisli return
-       Kleisli f >>> Kleisli g = Kleisli (\b -> f b >>= g)
+       id = Kleisli return
+       (Kleisli f) . (Kleisli g) = Kleisli (\b -> g b >>= f)
hunk ./Control/Category.hs 11
+-- http://hackage.haskell.org/trac/ghc/ticket/1773
+
hunk ./Control/Category.hs 15
+import Prelude hiding (id,(.))
+import qualified Prelude
+
+infixr 9 .
hunk ./Control/Category.hs 21
+-- | A class for categories.
+--   id and (.) must form a monoid.
hunk ./Control/Category.hs 24
-       identity :: cat a a
+       -- | the identity morphism
+       id :: cat a a
hunk ./Control/Category.hs 27
-       -- | Left-to-right composition
-       (>>>) :: cat a b -> cat b c -> cat a c
+       -- | morphism composition
+       (.) :: cat b c -> cat a b -> cat a c
hunk ./Control/Category.hs 32
-               identity >>> p = p
+               id . p = p
hunk ./Control/Category.hs 34
-               p >>> identity = p
+               p . id = p
hunk ./Control/Category.hs 36
-               (p >>> q) >>> r = p >>> (q >>> r)
+               (p . q) . r = p . (q . r)
hunk ./Control/Category.hs 40
-       identity = id
-       p >>> q = q . p
+       id = Prelude.id
+       (.) = (Prelude..)
hunk ./Control/Category.hs 45
-f <<< g = g >>> f
+(<<<) = (.)
hunk ./Control/Category.hs 47
+-- | Left-to-right composition
+(>>>) :: Category cat => cat a b -> cat b c -> cat a c
+f >>> g = g . f
}

Context:

[Fix doc building with Haddock 0.9
Simon Marlow <simonmar@microsoft.com>**20071024090947
 I was using a recent build here, which is more tolerant.
] 
[FIX #1258: document that openTempFile is secure(ish)
Simon Marlow <simonmar@microsoft.com>**20071023130928
 Also change the mode from 0666 to 0600, which seems like a more
 sensible value and matches what C's mkstemp() does.
] 
[Clean up .cabal file a bit
Duncan Coutts <duncan@haskell.org>**20071022132708
 specify build-type and cabal-version >= 1.2
 put extra-tmp-files in the right place
 use os(windows) rather than os(mingw32)
] 
[base in 6.8 and head branch should be version 3.0
Don Stewart <dons@galois.com>**20071007150408] 
[FIX #1652: openTempFile should accept an empty string for the directory
Simon Marlow <simonmar@microsoft.com>**20071018122345] 
[clean up duplicate code
Simon Marlow <simonmar@microsoft.com>**20071017141311] 
[expose the value of +RTS -N as GHC.Conc.numCapabilities (see #1733)
Simon Marlow <simonmar@microsoft.com>**20071009132042] 
[typo
Simon Marlow <simonmar@microsoft.com>**20070917130703] 
[put extra-tmp-files field in the right place
Simon Marlow <simonmar@microsoft.com>**20070914140812] 
[Add more entries to boring file
Ian Lynagh <igloo@earth.li>**20070913210500] 
[Add a boring file
Ian Lynagh <igloo@earth.li>**20070913204641] 
[TAG 2007-09-13
Ian Lynagh <igloo@earth.li>**20070913215720] 
Patch bundle hash:
c9be4454266d7c68b75bb60609db84d73ad949e1