syntax-example (empty) → 0.1.0.0

raw patch · 4 files changed

+111/−0 lines, 4 filesdep +attoparsecdep +basedep +lenssetup-changed

Dependencies added: attoparsec, base, lens, pretty, semi-iso, syntax, syntax-attoparsec, syntax-pretty, text

Files

• LICENSE +20/−0
• Main.hs +67/−0
• Setup.hs +2/−0
• syntax-example.cabal +22/−0

@@ -0,0 +1,20 @@+Copyright (c) 2014 Paweł Nowak++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 +1,67 @@+{-# LANGUAGE TemplateHaskell #-}+{-# LANGUAGE FlexibleContexts #-}+{-# LANGUAGE OverloadedStrings #-}++import           Control.Applicative+import           Control.Lens.TH+import qualified Data.Attoparsec.Text as AP+import           Data.Char+import           Data.SemiIsoFunctor+import           Data.Syntax (Syntax)+import qualified Data.Syntax as S+import qualified Data.Syntax.Attoparsec.Text as S+import qualified Data.Syntax.Char as S+import qualified Data.Syntax.Pretty as S+import           Data.Text (Text)+import qualified Data.Text.IO as T+import qualified Text.PrettyPrint as P++-- | A simple untyped lambda calculus.+data AST = Var Text+         | App AST AST+         | Abs Text AST+    deriving (Show)++$(makePrisms ''AST)++-- | A variable name.+name :: Syntax syn Text => syn Text+name = S.takeWhile1 isAlphaNum++-- | Encloses a symbol in parentheses.+parens :: Syntax syn Text => syn a -> syn a+parens m = S.char '(' */ S.spaces_ */ m /* S.spaces_ /* S.char ')'++-- | An atom is a variable or an expression in parentheses.+atom :: Syntax syn Text => syn AST+atom =  _Var /$/ name+    /|/ parens expr++-- | An expression of our lambda calculus.+expr :: Syntax syn Text => syn AST+expr =  _App /$/ atom /* S.spaces1 /*/ atom+    /|/ _Abs /$/ S.char '\\'   /* S.spaces_+              */ name          /* S.spaces+             /*  S.string "->" /* S.spaces+             /*/ expr +    /|/ atom++main :: IO ()+main = do+    -- Load the standard input.+    t <- T.getContents++    -- Try to parse it.+    case AP.parseOnly (S.getParser expr <* AP.skipSpace <* AP.endOfInput) t of+      Left err -> putStrLn err+      Right ast -> do+        -- If parsing succeeded print the AST.+        print ast+        +        -- Try to pretty print it.+        -- (Printing cannot really fail in this example)+        case S.runPrinter expr ast of+          Left err -> putStrLn err+          Right doc -> putStrLn (P.render doc)++    return ()

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

@@ -0,0 +1,22 @@+name:                syntax-example+version:             0.1.0.0+synopsis:            Example application using syntax, a library for abstract syntax descriptions.+license:             MIT+license-file:        LICENSE+author:              Paweł Nowak+maintainer:          Paweł Nowak <pawel834@gmail.com>+copyright:           Paweł Nowak 2014+category:            Data+build-type:          Simple+cabal-version:       >=1.10++source-repository head+  type:     git+  location: git@github.com:Pawel834/syntax-example.git++executable syntax-example+  main-is:             Main.hs+  build-depends:       base >= 4 && < 5, lens, semi-iso,+                       syntax, syntax-attoparsec, syntax-pretty,+                       attoparsec, pretty, text+  default-language:    Haskell2010