positive (empty) → 0.1

raw patch · 4 files changed

+113/−0 lines, 4 filesdep +basedep +natssetup-changed

Dependencies added: base, nats

Files

• COPYING +26/−0
• Setup.hs +4/−0
• positive.cabal +28/−0
• src/Numeric/Positive.hs +55/−0

@@ -0,0 +1,26 @@++Copyright (c) 2013, Hans Höglund+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 the <organization> nor the+      names of its 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 <COPYRIGHT HOLDER> 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 +1,4 @@+#! /usr/bin/env runhaskell++import Distribution.Simple+main = defaultMain

@@ -0,0 +1,28 @@++name:               positive+version:            0.1+cabal-version:      >= 1.10+author:             Hans Hoglund+maintainer:         Hans Hoglund <hans@hanshoglund.se>+license:            BSD3+license-file:       COPYING+synopsis:           Positive numbers.+category:           +tested-with:        GHC+build-type:         Simple++description:+    To be written.++source-repository head+    type:               git+    location:           git://github.com/hanshoglund/foobar.git++library+    build-depends:+        base            >= 4 && < 5,+        nats            >= 0.2 && < 1+    hs-source-dirs:     src+    default-language:   Haskell2010+    exposed-modules:+        Numeric.Positive

@@ -0,0 +1,55 @@++{-# LANGUAGE GeneralizedNewtypeDeriving #-}++module Numeric.Positive (+        Positive,+        positive+  ) where+import Numeric.Natural++newtype Positive = Positive { getPositive :: Natural } deriving+    ( +    Eq,+    Ord,+    -- Data,+    Real,+    -- Ix,+    -- Typeable,+    -- Bits,+    -- Hashable,+    Whole+    )++instance Show Positive where+  show (Positive n) = show n++instance Read Positive where+  readsPrec d = map (\(n, s) -> (fromInteger n, s)) . readsPrec d++instance Integral Positive where+  toInteger (Positive a) = toInteger a+  Positive a `quotRem` Positive b = (fromIntegral $ a `quot` b, fromIntegral $ a `rem` b)++instance Enum Positive where+  toEnum   = fromIntegral+  fromEnum = fromIntegral+  +instance Num Positive where+  Positive n + Positive m = Positive (n + m)+  Positive n * Positive m = Positive (n * m)+  Positive n - Positive m+    | r <  0 = error "Positive.(-): negative result"+    | r == 0 = error "Positive.(-): result zero"+    | otherwise   = Positive r+    where+      r = n - m+  abs      = id+  signum _ = 1+  fromInteger n+    | n >  0 = Positive (fromInteger n)+    | n == 0 = error "Positive.fromInteger: zero"+    | n <  0 = error "Positive.fromInteger: negative"++positive :: a -> (a -> a) -> Positive -> a+positive a f 1 = f a+positive a f n = f (positive a f $ pred n)