Limit (empty) → 1.0

raw patch · 4 files changed

+90/−0 lines, 4 filesdep +basesetup-changed

Dependencies added: base

Files

• LICENSE +19/−0
• Limit.cabal +25/−0
• Setup.hs +2/−0
• src/Data/Limit.hs +44/−0

@@ -0,0 +1,19 @@+Copyright © 2011 Nathaniel Soares++Permission is hereby granted, free of charge, to any person obtaining a copy of+this software and associated documentation files (the "Software"), to deal in+the Software without restriction, including without limitation the rights to+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of+the Software, and to permit persons to whom the Software is furnished to do so,+subject to the following conditions:++The above copyright notice and this permission notice shall be included in all+copies or substantial portions of the Software.++THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE+SOFTWARE.

@@ -0,0 +1,25 @@+Name:          Limit+Version:       1.0+License:       MIT+License-file:  LICENSE+Category:      Data+Synopsis:      Wrapper for data that can be unbounded+Description:   Limit n is like Maybe n, with (Bounded n) in place of (Just n)+               and Unbounded in place of Nothing. The only difference is that+               ∀n. Unbounded >= Bounded n, which makes Limit a good data type+               to deal with numbers that can become unbounded.+Author:        Nate Soares+Maintainer:    nate@natesoares.com+Build-Type:    Simple+Cabal-Version: >=1.6++source-repository head+    type: git+    location: git://github.com/Soares/Bound.hs.git++Library+    Hs-Source-Dirs:   src+    Build-Depends:    base >= 4 && < 5+    Exposed-modules:  Data.Limit+    Ghc-Options:      -Wall+    Ghc-Prof-Options: -auto-all

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

@@ -0,0 +1,44 @@+module Data.Limit+    ( Limit(Bounded,Unbounded)+    , isBounded+    , isUnbounded+    , fromBounded+    , fromLimit+    ) where++import Control.Monad ( liftM2 )++data Limit a = Bounded a | Unbounded+    deriving (Eq, Read, Show)++instance Ord a => Ord (Limit a) where+    x <= y = fromLimit (y == Unbounded) (liftM2 (<=) x y)++instance Functor Limit where+    fmap _ Unbounded = Unbounded+    fmap f (Bounded a) = Bounded (f a)++instance Monad Limit where+    Unbounded >>= _ = Unbounded+    (Bounded x) >>= k = k x++    Unbounded >> _ = Unbounded+    (Bounded _) >> k = k++    return = Bounded+    fail _ = Unbounded++isBounded :: Limit a -> Bool+isBounded Unbounded = False+isBounded _ = True++isUnbounded :: Limit a -> Bool+isUnbounded = not . isBounded++fromBounded :: Limit a -> a+fromBounded Unbounded = error "Limit.fromBounded: Unbounded" -- YOUR BAD+fromBounded (Bounded x) = x++fromLimit :: a -> Limit a -> a+fromLimit d Unbounded = d+fromLimit _ (Bounded x) = x