data-lens-ixset (empty) → 0.1.0

raw patch · 5 files changed

+176/−0 lines, 5 filesdep +QuickCheckdep +basedep +data-lenssetup-changed

Dependencies added: QuickCheck, base, data-lens, ixset

Files

• Data/Lens/IxSet.hs +63/−0
• LICENSE +30/−0
• Setup.hs +2/−0
• data-lens-ixset.cabal +28/−0
• test-data-lens-ixset.hs +53/−0

@@ -0,0 +1,63 @@+module Data.Lens.IxSet (ixLens) where++import Data.IxSet+import Data.Lens.Common+import Data.Typeable++-- |Focus on a key in an indexed set.+--+-- Given an 'IxSet' of people:+--+-- > people = fromList [ Person (FirstName "Edward A.") (LastName "Kmett")+-- >                   , Person (FirstName "Simon") (LastName "P. Jones")+-- >                   ]+--+-- We can now work with indices as lenses and fix Simon's last name:+--+-- > people' = lastName . ixLens (FirstName "Simon") ^= (LastName "Peyton-Jones") people+--+-- Perhaps more commonly you're working with an IxSet from inside a state monad such as with acid-state.  In that case usage is even easier:+--+-- > changeLastName = lastName . ixLens (FirstName "Simon") %= LastName "Peyton-Jones"+--+-- Feels backwards?  Lens composition uses 'Category' so we can flip it+-- around more intuitively using the composition arrows instead:+--+-- > changeLastName' = ixLens (FirstName "Simon") >>> lastName %= LastName "Peyton-Jones"+--+-- Here's the missing boilerplate:+--+-- > {-# LANGUAGE DeriveDataTypeable #-}+-- > {-# LANGUAGE TemplateHaskell #-}+-- >+-- > import Prelude hiding ((.))+-- > import Control.Category+-- > import Data.Data+-- >+-- > import Data.Lens+-- > import Data.Lens.Template+-- > import Data.IxSet+-- >+-- > data Person = Person { _firstName :: FirstName+-- >                      , _lastName  :: LastName+-- >                      } deriving (Show, Eq, Ord, Data, Typeable)+-- >+-- > mkLens ''Person+-- >+-- > newtype FirstName = FirstName String+-- >   deriving (Show, Eq, Ord, Data, Typeable)+-- >+-- > newtype LastName = LastName String+-- >   deriving (Show, Eq, Ord, Data, Typeable)+-- >+-- > instance Indexable Person where+-- >   empty = ixSet [ ixGen (Proxy :: Proxy FirstName)+-- >                 , ixGen (Proxy :: Proxy LastName)+-- >                 ]+ixLens :: (Indexable a, Typeable a, Typeable k, Ord a)+       => k -> Lens (IxSet a) (Maybe a)+ixLens k = lens get set+  where+    get          = getOne . getEQ k+    set (Just v) = updateIx k v+    set Nothing  = deleteIx k

@@ -0,0 +1,30 @@+Copyright (c) 2011, Dag Odenhall++All rights reserved.++Redistribution and use in source and binary forms, with or without+modification, are permitted provided that the following conditions are met:++    * Redistributions of source code must retain the above copyright+      notice, this list of conditions and the following disclaimer.++    * Redistributions in binary form must reproduce the above+      copyright notice, this list of conditions and the following+      disclaimer in the documentation and/or other materials provided+      with the distribution.++    * Neither the name of Dag Odenhall nor the names of other+      contributors may be used to endorse or promote products derived+      from this software without specific prior written permission.++THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

@@ -0,0 +1,2 @@+import Distribution.Simple+main = defaultMain

@@ -0,0 +1,28 @@+Name          : data-lens-ixset+Version       : 0.1.0+Synopsis      : A Lens for IxSet+Description   : Integrates Data.IxSet with Data.Lens.+Homepage      : https://github.com/dag/data-lens-ixset+License       : BSD3+License-file  : LICENSE+Author        : Dag Odenhall+Maintainer    : dag.odenhall@gmail.com+Category      : Control, Comonad, Data Structures+Build-type    : Simple+Cabal-version : >= 1.6++Source-repository head+  Type     : git+  Location : git://github.com/dag/data-lens-ixset.git++Library+  GHC-Options     : -Wall+  Exposed-modules : Data.Lens.IxSet+  Build-depends   : base >= 4 && < 5,+                    data-lens >= 2.0 && < 2.1,+                    ixset >= 1.0 && < 1.1++Executable test-data-lens-ixset+  GHC-Options   : -Wall+  Main-is       : test-data-lens-ixset.hs+  Build-depends : QuickCheck >= 2.4 && < 2.5

@@ -0,0 +1,53 @@+{-# LANGUAGE DeriveDataTypeable #-}+{-# LANGUAGE GeneralizedNewtypeDeriving #-}+{-# LANGUAGE TemplateHaskell #-}++module Main where++import Control.Monad+import Data.Data+import Data.IxSet+import Data.Lens.Common+import Data.Lens.IxSet+import System.Exit+import Test.QuickCheck+import Test.QuickCheck.All++data Person = Person FirstName LastName+  deriving (Show, Eq, Ord, Data, Typeable)++newtype FirstName = FirstName String+  deriving (Show, Eq, Ord, Data, Typeable, Arbitrary)++newtype LastName = LastName String+  deriving (Show, Eq, Ord, Data, Typeable, Arbitrary)++instance Indexable Person where+  empty = ixSet [ ixGen (Proxy :: Proxy FirstName)+                , ixGen (Proxy :: Proxy LastName)+                ]++prop_get_set :: FirstName -> LastName -> Bool+prop_get_set fname lname = getL l (setL l p empty) == p+  where+    l = ixLens fname+    p = Just $ Person fname lname++prop_set_get :: FirstName -> LastName -> Bool+prop_set_get fname lname = setL l (getL l ix) ix == ix+  where+    l  = ixLens fname+    ix = fromList [Person fname lname]++prop_set_set :: FirstName -> LastName -> LastName -> Bool+prop_set_set fname lname1 lname2 =+    setL l p1 (setL l p2 empty) == setL l p1 empty+  where+    l  = ixLens fname+    p1 = Just $ Person fname lname1+    p2 = Just $ Person fname lname2++main :: IO ()+main = do+  success <- $quickCheckAll+  unless success exitFailure