1 files changed, 183 insertions, 0 deletions
diff --git a/src/Parsers.hs b/src/Parsers.hs
new file mode 100644
index 0000000..1450a0e
--- /dev/null
+++ b/src/Parsers.hs
@@ -0,0 +1,183 @@
+{-# LANGUAGE FlexibleContexts, GeneralizedNewtypeDeriving #-}
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  Xmobar.Parsers
+-- Copyright   :  (c) Andrea Rossato
+-- License     :  BSD-style (see LICENSE)
+--
+-- Maintainer  :  Jose A. Ortega Ruiz <jao@gnu.org>
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-- Parsers needed for Xmobar, a text based status bar
+--
+-----------------------------------------------------------------------------
+
+module Parsers
+    ( parseString
+    , parseTemplate
+    , parseConfig
+    ) where
+
+import Config
+import Runnable
+import Commands
+
+import qualified Data.Map as Map
+import Text.ParserCombinators.Parsec
+import Text.ParserCombinators.Parsec.Perm
+
+-- | Runs the string parser
+parseString :: Config -> String -> IO [(String, String)]
+parseString c s =
+    case parse (stringParser (fgColor c)) "" s of
+      Left  _ -> return [("Could not parse string: " ++ s, fgColor c)]
+      Right x -> return (concat x)
+
+-- | Gets the string and combines the needed parsers
+stringParser :: String -> Parser [[(String, String)]]
+stringParser c = manyTill (textParser c <|> colorParser) eof
+
+-- | Parses a maximal string without color markup.
+textParser :: String -> Parser [(String, String)]
+textParser c = do s <- many1 $
+                    noneOf "<" <|>
+                    ( try $ notFollowedBy' (char '<')
+                                           (string "fc=" <|> string "/fc>" ) )
+                  return [(s, c)]
+
+-- | Wrapper for notFollowedBy that returns the result of the first parser.
+--   Also works around the issue that, at least in Parsec 3.0.0, notFollowedBy
+--   accepts only parsers with return type Char.
+notFollowedBy' :: Parser a -> Parser b -> Parser a
+notFollowedBy' p e = do x <- p
+                        notFollowedBy $ try (e >> return '*')
+                        return x
+
+-- | Parsers a string wrapped in a color specification.
+colorParser :: Parser [(String, String)]
+colorParser = do
+  c <- between (string "<fc=") (string ">") colors
+  s <- manyTill (textParser c <|> colorParser) (try $ string "</fc>")
+  return (concat s)
+
+-- | Parses a color specification (hex or named)
+colors :: Parser String
+colors = many1 (alphaNum <|> char ',' <|> char '#')
+
+-- | Parses the output template string
+templateStringParser :: Config -> Parser (String,String,String)
+templateStringParser c = do
+  s   <- allTillSep c
+  com <- templateCommandParser c
+  ss  <- allTillSep c
+  return (com, s, ss)
+
+-- | Parses the command part of the template string
+templateCommandParser :: Config -> Parser String
+templateCommandParser c =
+  let chr = char . head . sepChar
+  in  between (chr c) (chr c) (allTillSep c)
+
+-- | Combines the template parsers
+templateParser :: Config -> Parser [(String,String,String)]
+templateParser = many . templateStringParser
+
+-- | Actually runs the template parsers
+parseTemplate :: Config -> String -> IO [(Runnable,String,String)]
+parseTemplate c s =
+    do str <- case parse (templateParser c) "" s of
+                Left _  -> return [("","","")]
+                Right x -> return x
+       let cl = map alias (commands c)
+           m  = Map.fromList $ zip cl (commands c)
+       return $ combine c m str
+
+-- | Given a finite "Map" and a parsed template produce the resulting
+-- output string.
+combine :: Config -> Map.Map String Runnable -> [(String, String, String)] -> [(Runnable,String,String)]
+combine _ _ [] = []
+combine c m ((ts,s,ss):xs) = (com, s, ss) : combine c m xs
+    where com  = Map.findWithDefault dflt ts m
+          dflt = Run $ Com ts [] [] 10
+
+allTillSep :: Config -> Parser String
+allTillSep = many . noneOf . sepChar
+
+stripComments :: String -> String
+stripComments = unlines . map (drop 5 . strip False . (replicate 5 ' '++)) . lines
+    where strip m ('-':'-':xs) = if m then "--" ++ strip m xs else ""
+          strip m ('\\':xss) = case xss of
+                                '\\':xs -> '\\' : strip m xs
+                                _ -> strip m $ drop 1 xss
+          strip m ('"':xs) = '"': strip (not m) xs
+          strip m (x:xs) = x : strip m xs
+          strip _ [] = []
+
+-- | Parse the config, logging a list of fields that were missing and replaced
+-- by the default definition.
+parseConfig :: String -> Either ParseError (Config,[String])
+parseConfig = runParser parseConf fields "Config" . stripComments
+    where
+      parseConf = do
+        many space
+        sepEndSpc ["Config","{"]
+        x <- perms
+        eof
+        s <- getState
+        return (x,s)
+
+      perms = permute $ Config
+              <$?> pFont         <|?> pBgColor
+              <|?> pFgColor      <|?> pPosition
+              <|?> pBorder       <|?> pBdColor
+              <|?> pLowerOnStart <|?> pCommands
+              <|?> pSepChar      <|?> pAlignSep
+              <|?> pTemplate
+
+      fields    = [ "font", "bgColor", "fgColor", "sepChar", "alignSep"
+                  , "border", "borderColor" ,"template", "position"
+                  , "lowerOnStart", "commands"]
+      pFont     = strField font     "font"
+      pBgColor  = strField bgColor  "bgColor"
+      pFgColor  = strField fgColor  "fgColor"
+      pBdColor  = strField borderColor "borderColor"
+      pSepChar  = strField sepChar  "sepChar"
+      pAlignSep = strField alignSep "alignSep"
+      pTemplate = strField template "template"
+
+      pPosition     = field position     "position"     $ tillFieldEnd >>= read' "position"
+      pLowerOnStart = field lowerOnStart "lowerOnStart" $ tillFieldEnd >>= read' "lowerOnStart"
+      pBorder       = field border       "border"       $ tillFieldEnd >>= read' "border"
+      pCommands     = field commands     "commands"     $ readCommands
+
+      staticPos = do string "Static"
+                     wrapSkip (string "{")
+                     p <- many (noneOf "}")
+                     wrapSkip (string "}")
+                     string ","
+                     return ("Static {"  ++ p  ++ "}")
+      tillFieldEnd = staticPos <|> many (noneOf ",}\n\r")
+
+      commandsEnd  = wrapSkip (string "]") >> oneOf "},"
+      readCommands = manyTill anyChar (try commandsEnd) >>= read' commandsErr . flip (++) "]"
+
+      strField e n = field e n . between (strDel "start" n) (strDel "end" n) . many $ noneOf "\"\n\r"
+      strDel   t n = char '"' <?> strErr t n
+      strErr   t n = "the " ++ t ++ " of the string field " ++ n ++ " - a double quote (\")."
+
+      wrapSkip   x = many space >> x >>= \r -> many space >> return r
+      sepEndSpc    = mapM_ (wrapSkip . try . string)
+      fieldEnd     = many $ space <|> oneOf ",}"
+      field  e n c = (,) (e defaultConfig) $
+                     updateState (filter (/= n)) >> sepEndSpc [n,"="] >>
+                     wrapSkip c >>= \r -> fieldEnd >> return r
+
+      read' d s = case reads s of
+                    [(x, _)] -> return x
+                    _        -> fail $ "error reading the " ++ d ++ " field: " ++ s
+
+commandsErr :: String
+commandsErr = "commands: this usually means that a command could not be parsed.\n" ++
+              "The error could be located at the begining of the command which follows the offending one."
+