acme-smuggler (empty) → 0.1.0.1

raw patch · 6 files changed

+132/−0 lines, 6 filesdep +acme-smugglerdep +basedep +hspecsetup-changed

Dependencies added: acme-smuggler, base, hspec

Files

• LICENSE +30/−0
• README.md +26/−0
• Setup.hs +2/−0
• acme-smuggler.cabal +35/−0
• src/Acme/Smuggler.hs +25/−0
• test/Spec.hs +14/−0

@@ -0,0 +1,30 @@+Copyright Ben Clifford (c) 2016++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 Author name here 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.

@@ -0,0 +1,26 @@+ACME Smuggler+=============++The () type has only one value, also called () with no+internal structure.++Nevertheless, acme-smuggler allows you to smuggle+arbitrary values into () and discover them later:++```haskell+> x = smuggle "hello"+> :t x+x :: ()++> y = smuggle (7 :: Integer)+> :t y+y :: ()++> discover x :: Maybe String+Just "hello"+> discover y :: Maybe Integer+Just 7+> discover x :: Maybe Integer+Nothing+```+

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

@@ -0,0 +1,35 @@+name:                acme-smuggler+version:             0.1.0.1+synopsis:            Smuggle arbitrary values in ()+description:         Please see README.md+homepage:            https://github.com/benclifford/acme-smuggler+license:             BSD3+license-file:        LICENSE+author:              Ben Clifford <benc@hawaga.org.uk>+maintainer:          Ben Clifford <benc@hawaga.org.uk>+copyright:           2016 Ben Clifford+category:            ACME+build-type:          Simple+extra-source-files:  README.md+cabal-version:       >=1.10++library+  hs-source-dirs:      src+  exposed-modules:     Acme.Smuggler+  build-depends:       base >= 4.7 && < 5+  default-language:    Haskell2010+  ghc-options:         -Wall++test-suite acme-smuggler-test+  type:                exitcode-stdio-1.0+  hs-source-dirs:      test+  main-is:             Spec.hs+  build-depends:       base+                     , acme-smuggler+                     , hspec+  ghc-options:         -threaded -rtsopts -with-rtsopts=-N+  default-language:    Haskell2010++source-repository head+  type:     git+  location: https://github.com/benclifford/acme-smuggler

@@ -0,0 +1,25 @@+module Acme.Smuggler+    ( inj, prj, smuggle, discover+    ) where++import Data.Typeable (Typeable)+import Data.Dynamic (toDyn, fromDynamic)+import System.IO.Unsafe (unsafePerformIO)+import Control.Exception (try, throw)++-- | fancy name for smuggle+inj :: Typeable t => t -> ()+inj = smuggle++-- | fancy name for discover+prj :: Typeable t => () -> Maybe t+prj = discover++smuggle :: Typeable t => t -> ()+smuggle v = unsafePerformIO $ throw (toDyn v)++discover :: Typeable t => () -> Maybe t+discover v = either (fromDynamic) (const Nothing)+  $ unsafePerformIO+  $ try+  $ case v of () -> return ()

@@ -0,0 +1,14 @@+import Acme.Smuggler+import Test.Hspec++main :: IO ()+main = hspec $ do+  describe "prj . inj" $ do+    it "conveys an integer" $ (prj . inj) (7 :: Integer) `shouldBe` Just (7 :: Integer)+    it "gives Nothing when going from an integer to a string" $+      (prj . inj) (7 :: Integer) `shouldBe` (Nothing :: Maybe String)++  describe "prj" $ do+    it "gives Nothing when projecting from a real ()" $+      (prj ()) `shouldBe` (Nothing :: Maybe Integer)+