type-level-natural-number (empty) → 1.0

raw patch · 4 files changed

+148/−0 lines, 4 filesdep +basesetup-changed

Dependencies added: base

Files

LICENSE +22/−0
Setup.hs +2/−0
TypeLevel/NaturalNumber.hs +89/−0
type-level-natural-number.cabal +35/−0

+ LICENSE view

@@ -0,0 +1,22 @@+Copyright (c) 2010, Gregory M. Crosswhite+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.++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

+ TypeLevel/NaturalNumber.hs view

@@ -0,0 +1,89 @@+{- Copyright (c) 2008, Scott E. Dillard. All rights reserved. -}+{- Copyright (c) 2010, Gregory M. Crosswhite. All rights reserved. -}++{-# LANGUAGE EmptyDataDecls #-}++module TypeLevel.NaturalNumber where++data Zero+data SuccessorTo n++type N0  = Zero+type N1  = SuccessorTo N0+type N2  = SuccessorTo N1+type N3  = SuccessorTo N2+type N4  = SuccessorTo N3+type N5  = SuccessorTo N4+type N6  = SuccessorTo N5+type N7  = SuccessorTo N6+type N8  = SuccessorTo N7+type N9  = SuccessorTo N8+type N10 = SuccessorTo N9+type N11 = SuccessorTo N10+type N12 = SuccessorTo N11+type N13 = SuccessorTo N12+type N14 = SuccessorTo N13+type N15 = SuccessorTo N14++type One      = N1+type Two      = N2+type Three    = N3+type Four     = N4+type Five     = N5+type Six      = N6+type Seven    = N7+type Eight    = N8+type Nine     = N9+type Ten      = N10+type Eleven   = N11+type Twelve   = N12+type Thirteen = N13+type Fourteen = N14+type Fifteen  = N15++n0  :: N0  ; n0  = undefined+n1  :: N1  ; n1  = undefined+n2  :: N2  ; n2  = undefined+n3  :: N3  ; n3  = undefined+n4  :: N4  ; n4  = undefined+n5  :: N5  ; n5  = undefined+n6  :: N6  ; n6  = undefined+n7  :: N7  ; n7  = undefined+n8  :: N8  ; n8  = undefined+n9  :: N9  ; n9  = undefined+n10 :: N10 ; n10  = undefined+n11 :: N11 ; n11  = undefined+n12 :: N12 ; n12  = undefined+n13 :: N13 ; n13  = undefined+n14 :: N14 ; n14  = undefined+n15 :: N15 ; n15  = undefined++predecessorOf :: SuccessorTo n -> n+predecessorOf _ = undefined++successorTo :: n -> SuccessorTo n+successorTo _ = undefined++class NaturalNumber n where+    naturalNumberAsInt :: n -> Int+instance NaturalNumber Zero where+    naturalNumberAsInt _ = 0+instance NaturalNumber n => NaturalNumber (SuccessorTo n) where+    naturalNumberAsInt x = 1 + naturalNumberAsInt (predecessorOf x)++instance Show Zero where+    show _ = "0"+instance NaturalNumber n => Show (SuccessorTo n) where+    show = show . (+1) . naturalNumberAsInt . predecessorOf++instance Eq Zero where+    (==) _ _ = True+    (/=) _ _ = False+instance NaturalNumber n => Eq (SuccessorTo n) where+    (==) _ _ = True+    (/=) _ _ = False++instance Ord Zero where+    compare _ _ = EQ+instance NaturalNumber n => Ord (SuccessorTo n) where+    compare _ _ = EQ

+ type-level-natural-number.cabal view

@@ -0,0 +1,35 @@+Name:                type-level-natural-number+Version:             1.0+License:             BSD3+License-file:        LICENSE+Author:              Gregory Crosswhite+Maintainer:          Gregory Crosswhite <gcross@phys.washington.edu>+Stability:           Provisional+Synopsis:            Simple, Haskell 2010-compatible type level natural numbers+Description:         This is a simple, Haskell 2010 compatible implementation+                     of type-level natural numbers.  Operations requiring+                     non-Haskell 2010 language extensions have been split+                     into a separate package.++		     The difference between this package and the many+                     others on Hackage implementing type-level+                     naturals is its emphasis on simplicity.  It only+                     supports non-negative natural numbers, and only+                     the successor and predicessor operations.  It+                     represents natural numbers using a type-level+                     linked list, so it is not intended to be used for+                     representing large numbers.  Pre-defined aliases+                     for natural numbers up to 15 are provided.++                     The code for this package was largely inspired by+                     the type-level natural numbers in the excellent+                     Vec package.++Cabal-version: >=1.6+Build-type: Simple+Category: Type System,Data++Library+    Build-depends:   base >= 3 && < 5+    Exposed-modules: TypeLevel.NaturalNumber+    Extensions:	     EmptyDataDecls