while-lang-parser (empty) → 0.1.0.0

raw patch · 5 files changed

+280/−0 lines, 5 filesdep +basedep +indentsdep +parsecsetup-changed

Dependencies added: base, indents, parsec

Files

LICENSE +30/−0
Language/While/Parser.hs +181/−0
Language/While/Types.hs +42/−0
Setup.hs +2/−0
while-lang-parser.cabal +25/−0

+ LICENSE view

@@ -0,0 +1,30 @@+Copyright (c) 2013, David Nilsson And Patrik Berggren++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 David Nilsson And Patrik Berggren 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.

+ Language/While/Parser.hs view

@@ -0,0 +1,181 @@+--------------------------------------------------------------------+-- |+-- Module : Language.While.Parser+--+-- Provides parsing of while-language code.+-- Supports reading either a file or stdin, resulting in an AST.++module Language.While.Parser (loadFile, loadStdin) where++import Control.Applicative ((<$>), (<*))+import Control.Monad (liftM)+import Language.While.Types+import Text.Parsec+import Text.Parsec.Expr+import Text.Parsec.Indent+import Text.Parsec.Language (GenLanguageDef)+import Text.Parsec.String+import qualified Text.Parsec.Token as P++-- | Parse the specified file and return either failure or the program.+loadFile :: FilePath -> IO (Either String Stm)+loadFile path = parseString "Failed to parse file; " <$> readFile path++-- | Parse stdin and return either failure or the program.+loadStdin :: IO (Either String Stm)+loadStdin = parseString "Failed to parse stdin; " <$> getContents++-- | Parse the supplied string and return either failure or the program.+parseString errMsg input =+  case parseResult of+    Left err -> Left $ errMsg ++ show err+    Right res -> Right res+  where+  parseResult = runIndent "" $ runParserT program () "" input++-- | Parse a binary operation.+binaryOp name fun = Infix body+  where+  body = reservedOp name >> return fun++-- | Parse a prefix operation, e.g. negation.+prefixOp name fun = Prefix $ reservedOp name >> return fun++-- | Parse a whole program, as a series of statements.+program = do+  whiteSpace+  st <- semiSep consecutive+  return $ foldr1 Scomp . concat $ st++-- | Parse a single statement followed optionally by another one.+-- | Needs to be done due to the while-statement.+consecutive = do+  s1 <- statement+  (s1:) <$> option [] (liftM return statement)++-- | Parse a program statement.+statement+  =   try stmAssignment+  <|> try stmTryCatch+  <|> try stmSkip+  <|> try stmIf+  <|> try stmWhile <* whiteSpace+  <|> parens stmWhile <* whiteSpace++-- | Parse an arithmetic atom.+arithmeticAtom+  =   Numeral <$> integer+  <|> Variable <$> identifier+  <|> parens arithmeticExpr++-- | Table of supported arithmetic operations.+arithmeticOperation =+  [ [binaryOp "*" Amul AssocLeft]+  , [binaryOp "+" Aadd AssocLeft, binaryOp "-" Asub AssocLeft , binaryOp "/" Adiv AssocLeft ]+  ]++-- Parse an arithmetic expression, consisting of parenthesis and supported operators.+arithmeticExpr = buildExpressionParser arithmeticOperation arithmeticAtom++-- | Since Bexp members operate over different domains,+--   there is some boxing/unboxing being done with WrapAtom.+data WrapAtom+  = BexpW Bexp+  | AexpW Aexp++-- | Parse a boolean atom.+booleanAtom+  =   (try (symbol "true") >> truthVal Btrue)+  <|> (try (symbol "false") >> truthVal Bfalse)+  <|> (try $ AexpW <$> arithmeticExpr)+  <|> parens booleanExpr'+  where truthVal = return . BexpW++-- | Table of supported boolean operations.+booleanOperation =+  [ [prefixOp "!" bneg]+  , [binaryOp "=" beq AssocLeft+   , binaryOp "<=" bleq AssocLeft+   , binaryOp "^" band AssocLeft ]+  ]+  where+  bneg (BexpW b) = BexpW $ Bneg b+  beq (AexpW a1) (AexpW a2) = BexpW $ Beq a1 a2+  bleq (AexpW a1) (AexpW a2) = BexpW $ Bleq a1 a2+  band (BexpW b1) (BexpW b2) = BexpW $ Band b1 b2++-- | Parse a boolean expression.+booleanExpr = do+  result <- booleanExpr'+  case result of+    (BexpW val) -> return val+    _ -> error "Parse error: failed to extract boolean"++booleanExpr' = buildExpressionParser booleanOperation booleanAtom++-- | Assignment statement.+stmAssignment = do+  var <- identifier+  symbol ":="+  expr <- arithmeticExpr+  return $ Sass var expr++-- | Skip statement.+stmSkip = symbol "skip" >> return Sskip++-- | If-then-else statement.+stmIf = do+  symbol "if"+  check <- booleanExpr+  symbol "then"+  s1 <- program+  symbol "else"+  s2 <- program+  return $ Sif check s1 s2++-- | While statement.+stmWhile = do+  symbol "while"+  check <- booleanExpr+  symbol "do"++  prog <- liftM (foldr1 Scomp) . block $ do+    s <- statement+    optional semi+    return s++  return $ Swhile check prog++-- | Try-catch statement.+stmTryCatch = do+  symbol "try"+  s1 <- program+  symbol "catch"+  s2 <- program+  return $ Stry s1 s2++identifier = P.identifier whileLexer+integer = P.integer whileLexer+parens = P.parens whileLexer+reservedOp = P.reservedOp whileLexer+semi = P.semi whileLexer+symbol = P.symbol whileLexer+semiSep = P.semiSep whileLexer+whiteSpace = P.whiteSpace whileLexer++whileLexer = P.makeTokenParser whileStyle++whileStyle :: Monad m => GenLanguageDef String u m+whileStyle = P.LanguageDef+  { P.commentStart   = ""+  , P.commentEnd     = ""+  , P.commentLine    = "#"+  , P.nestedComments = True+  , P.identStart     = letter <|> char '_'+  , P.identLetter    = alphaNum <|> oneOf "_'"+  , P.opStart        = P.opLetter whileStyle+  , P.opLetter       = oneOf ":!#$%&*+./<=>?@\\^|-~"+  , P.reservedOpNames= []+  , P.reservedNames  = []+  , P.caseSensitive  = True+  }

+ Language/While/Types.hs view

@@ -0,0 +1,42 @@+--------------------------------------------------------------------+-- |+-- Module : Language.While.Types+--+-- Provides shared type definitions forming the parsed AST.+--++module Language.While.Types where++-- | Variables type alias.+type Varname = String++-- | Arithmetic expressions, including integer division.+data Aexp+  = Numeral Integer+  | Variable Varname +  | Aadd Aexp Aexp+  | Asub Aexp Aexp+  | Amul Aexp Aexp+  | Adiv Aexp Aexp+  deriving (Show, Eq)+++-- | Boolean expressions.+data Bexp+  = Btrue+  | Bfalse+  | Beq Aexp Aexp+  | Bleq Aexp Aexp+  | Bneg Bexp+  | Band Bexp Bexp+  deriving (Show, Eq)++-- | Statements, including try-catch clauses.+data Stm+  = Sass Varname Aexp +  | Sskip+  | Scomp Stm Stm+  | Sif Bexp Stm Stm+  | Swhile Bexp Stm+  | Stry Stm Stm+  deriving (Show, Eq)

+ Setup.hs view

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

+ while-lang-parser.cabal view

@@ -0,0 +1,25 @@+name:                while-lang-parser+version:             0.1.0.0+synopsis:            Parser for the While language.+description:         Parser for the While language described in /Semantics with Applications/ by Nielson and Nielson.++homepage:            https://github.com/davnils/while-lang-parser++license:             BSD3+license-file:        LICENSE++author:              David Nilsson And Patrik Berggren+maintainer:          nilsson.dd+code@gmail.com++category:            Language++build-type:          Simple+cabal-version:       >=1.8+++library+  exposed-modules:     Language.While.Parser, Language.While.Types+  build-depends:+    base >= 4.5 && < 5,+    parsec >= 3.1 && < 4,+    indents >= 0.3 && < 0.4