groups (empty) → 0.1

raw patch · 4 files changed

+87/−0 lines, 4 filesdep +basesetup-changed

Dependencies added: base

Files

LICENSE +30/−0
Setup.hs +2/−0
groups.cabal +19/−0
src/Data/Group.hs +36/−0

+ LICENSE view

@@ -0,0 +1,30 @@+Copyright (c) 2013, Nathan "Taneb" van Doorn++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 Nathan "Taneb" van Doorn 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.

+ Setup.hs view

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

+ groups.cabal view

@@ -0,0 +1,19 @@+name:                groups+version:             0.1+synopsis:            Haskell 98 groups+description:         +  Haskell 98 groups. A group is a monoid with invertibility.+license:             BSD3+license-file:        LICENSE+author:              Nathan "Taneb" van Doorn+maintainer:          nvd1234@gmail.com+copyright:           Copyright (C) 2013 Nathan van Doorn+category:            Algebra, Data, Math+build-type:          Simple+cabal-version:       >=1.8++library+  exposed-modules:     Data.Group+  -- other-modules:       +  build-depends:       base ==4.5.*+  hs-source-dirs:      src

+ src/Data/Group.hs view

@@ -0,0 +1,36 @@+module Data.Group where++import Data.Monoid++-- |A 'Group' is a 'Monoid' plus a function, 'invert', such that: +--+-- @a <> invert a == mempty@+class Monoid m => Group m where+  invert :: m -> m+  +instance Group () where+  invert () = ()++instance Num a => Group (Sum a) where+  invert = Sum . negate . getSum+  {-# INLINE invert #-}+  +instance Fractional a => Group (Product a) where+  invert = Product . recip . getProduct+  {-# INLINE invert #-}++instance Group a => Group (Dual a) where+  invert = Dual . invert . getDual+  {-# INLINE invert #-}+  +instance (Group a, Group b) => Group (a, b) where+  invert (a, b) = (invert a, invert b)+  +instance (Group a, Group b, Group c) => Group (a, b, c) where+  invert (a, b, c) = (invert a, invert b, invert c)++instance (Group a, Group b, Group c, Group d) => Group (a, b, c, d) where+  invert (a, b, c, d) = (invert a, invert b, invert c, invert d)++instance (Group a, Group b, Group c, Group d, Group e) => Group (a, b, c, d, e) where+  invert (a, b, c, d, e) = (invert a, invert b, invert c, invert d, invert e)