data-carousel (empty) → 0.1.0.0

raw patch · 4 files changed

+154/−0 lines, 4 filesdep +basedep +containersdep +lenssetup-changed

Dependencies added: base, containers, lens

Files

LICENSE +20/−0
Setup.hs +2/−0
data-carousel.cabal +26/−0
src/Data/Carousel.hs +106/−0

+ LICENSE view

@@ -0,0 +1,20 @@+Copyright (c) 2014 AlephCloud, Inc.++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.

+ Setup.hs view

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

+ data-carousel.cabal view

@@ -0,0 +1,26 @@+-- Initial data-carousel.cabal generated by cabal init.  For further+-- documentation, see http://haskell.org/cabal/users-guide/++name:                data-carousel+version:             0.1.0.0+synopsis:            A rotating sequence data structure+license:             MIT+license-file:        LICENSE+author:              Jon Sterling+maintainer:          jon@jonmsterling.com+copyright:           Copyright (c) 2014 AlephCloud, Inc.+category:            Data+build-type:          Simple+cabal-version:       >=1.10++source-repository head+    type: git+    location: https://github.com/alephcloud/hs-data-carousel.git++library+  exposed-modules:     Data.Carousel+  build-depends:       base >=4.7 && <4.8,+                       containers >=0.5.5.1,+                       lens >=4.5+  hs-source-dirs:      src+  default-language:    Haskell2010

+ src/Data/Carousel.hs view

@@ -0,0 +1,106 @@+{-# LANGUAGE RecordWildCards #-}+{-# LANGUAGE LambdaCase #-}+{-# LANGUAGE RankNTypes #-}+{-# LANGUAGE UnicodeSyntax #-}++-- |+-- Module: Data.Carousel+-- Copyright: Copyright © 2014 AlephCloud Systems, Inc.+-- License: MIT+-- Maintainer: Jon Sterling <jsterling@alephcloud.com>+-- Stability: experimental+--+module Data.Carousel+( Carousel+, empty+, cursor+, moveLeft+, moveRight+, dropCursor+, nub+, append+, clSequence+, clList+) where++import Control.Lens+import qualified Data.Foldable as F+import qualified Data.List as L+import qualified Data.Sequence as S++newtype Carousel α+  = Carousel+  { _clSequence ∷ S.Seq α+  } deriving (Show, Eq)++instance Functor Carousel where+  fmap f (Carousel sq) = Carousel $ fmap f sq++instance F.Foldable Carousel where+  foldMap f (Carousel sq) = F.foldMap f sq++instance Traversable Carousel where+  traverse f (Carousel sq) = fmap Carousel (traverse f sq)++clSequence ∷ Iso (Carousel α) (Carousel β) (S.Seq α) (S.Seq β)+clSequence = iso _clSequence Carousel++clList ∷ Iso (Carousel α) (Carousel β) [α] [β]+clList = clSequence . iso F.toList S.fromList+++-- | There is guaranteed to be a cursor so long as the carousel is non-empty.+cursor ∷ Traversal' (Carousel α) α+cursor = clSequence . _head++-- | You can delete the cursor from the carousel; the items to its right will+-- move one over to the left.+dropCursor+  ∷ Carousel α+  → Carousel α+dropCursor = clSequence %~ (^. _tail)++-- | The carousel may be rotated to the right; this operation is written so as+-- to always guarantee the presence of a cursor in a non-empty carousel.+moveRight+  ∷ Carousel α+  → Carousel α+moveRight = clSequence %~ rotate . S.viewl+  where+    rotate+      ∷ S.ViewL α+      → S.Seq α+    rotate S.EmptyL = S.empty+    rotate (x S.:< xs) = xs S.|> x++-- | The carousel may be rotated to the left; this operation is written so as+-- to always guarantee the presence of a cursor in a non-empty carousel.+moveLeft+  ∷ Carousel α+  → Carousel α+moveLeft = clSequence %~ rotate . S.viewr+  where+    rotate+      ∷ S.ViewR α+      → S.Seq α+    rotate S.EmptyR = S.empty+    rotate (xs S.:> x) = x S.<| xs++-- | The empty carousel.+empty+  ∷ Carousel α+empty = Carousel S.empty++-- | Append a list of elements to the right side of the carousel.+append+  ∷ [α]+  → Carousel α+  → Carousel α+append xs = clSequence %~ (S.>< S.fromList xs)++-- | Remove all duplicate elements from the carousel. (TODO: this is inefficient)+nub+  ∷ Eq α+  ⇒ Carousel α+  → Carousel α+nub = clList %~ L.nub