Parsers wee refactoring

1 files changed, 146 insertions, 0 deletions

diff --git a/src/lib/Xmobar/X11/Parsers.hs b/src/lib/Xmobar/X11/Parsers.hs
new file mode 100644
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+++ b/src/lib/Xmobar/X11/Parsers.hs
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+{-# LANGUAGE FlexibleContexts #-}
+
+-----------------------------------------------------------------------------
+-- |
+-- Module      :  Xmobar.Parsers
+-- Copyright   :  (c) Andrea Rossato
+-- License     :  BSD-style (see LICENSE)
+--
+-- Maintainer  :  Jose A. Ortega Ruiz <jao@gnu.org>
+-- Stability   :  unstable
+-- Portability :  unportable
+--
+-- Parsing for template substrings
+--
+-----------------------------------------------------------------------------
+
+module Xmobar.X11.Parsers (parseString, Widget(..)) where
+
+import Xmobar.Config
+import Xmobar.Actions
+
+import Control.Monad (guard, mzero)
+import Text.ParserCombinators.Parsec
+import Graphics.X11.Types (Button)
+
+data Widget = Icon String | Text String
+
+type ColorString = String
+type FontIndex   = Int
+
+-- | Runs the string parser
+parseString :: Config -> String
+               -> IO [(Widget, ColorString, FontIndex, Maybe [Action])]
+parseString c s =
+    case parse (stringParser (fgColor c) 0 Nothing) "" s of
+      Left  _ -> return [(Text $ "Could not parse string: " ++ s
+                          , fgColor c
+                          , 0
+                          , Nothing)]
+      Right x -> return (concat x)
+
+allParsers :: ColorString
+           -> FontIndex
+           -> Maybe [Action]
+           -> Parser [(Widget, ColorString, FontIndex, Maybe [Action])]
+allParsers c f a =  textParser c f a
+                <|> try (iconParser c f a)
+                <|> try (rawParser c f a)
+                <|> try (actionParser c f a)
+                <|> try (fontParser c a)
+                <|> colorParser f a
+
+-- | Gets the string and combines the needed parsers
+stringParser :: String -> FontIndex -> Maybe [Action]
+                -> Parser [[(Widget, ColorString, FontIndex, Maybe [Action])]]
+stringParser c f a = manyTill (allParsers c f a) eof
+
+-- | Parses a maximal string without color markup.
+textParser :: String -> FontIndex -> Maybe [Action]
+              -> Parser [(Widget, ColorString, FontIndex, Maybe [Action])]
+textParser c f a = do s <- many1 $
+                            noneOf "<" <|>
+                              try (notFollowedBy' (char '<')
+                                    (try (string "fc=")  <|>
+                                     try (string "fn=")  <|>
+                                     try (string "action=") <|>
+                                     try (string "/action>") <|>
+                                     try (string "icon=") <|>
+                                     try (string "raw=") <|>
+                                     try (string "/fn>") <|>
+                                     string "/fc>"))
+                      return [(Text s, c, f, a)]
+
+-- | Parse a "raw" tag, which we use to prevent other tags from creeping in.
+-- The format here is net-string-esque: a literal "<raw=" followed by a
+-- string of digits (base 10) denoting the length of the raw string,
+-- a literal ":" as digit-string-terminator, the raw string itself, and
+-- then a literal "/>".
+rawParser :: ColorString
+          -> FontIndex
+          -> Maybe [Action]
+          -> Parser [(Widget, ColorString, FontIndex, Maybe [Action])]
+rawParser c f a = do
+  string "<raw="
+  lenstr <- many1 digit
+  char ':'
+  case reads lenstr of
+    [(len,[])] -> do
+      guard ((len :: Integer) <= fromIntegral (maxBound :: Int))
+      s <- count (fromIntegral len) anyChar
+      string "/>"
+      return [(Text s, c, f, a)]
+    _ -> mzero
+
+-- | 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
+
+iconParser :: String -> FontIndex -> Maybe [Action]
+              -> Parser [(Widget, ColorString, FontIndex, Maybe [Action])]
+iconParser c f a = do
+  string "<icon="
+  i <- manyTill (noneOf ">") (try (string "/>"))
+  return [(Icon i, c, f, a)]
+
+actionParser :: String -> FontIndex -> Maybe [Action]
+                -> Parser [(Widget, ColorString, FontIndex, Maybe [Action])]
+actionParser c f act = do
+  string "<action="
+  command <- choice [between (char '`') (char '`') (many1 (noneOf "`")),
+                   many1 (noneOf ">")]
+  buttons <- (char '>' >> return "1") <|> (space >> spaces >>
+    between (string "button=") (string ">") (many1 (oneOf "12345")))
+  let a = Spawn (toButtons buttons) command
+      a' = case act of
+        Nothing -> Just [a]
+        Just act' -> Just $ a : act'
+  s <- manyTill (allParsers c f a') (try $ string "</action>")
+  return (concat s)
+
+toButtons :: String -> [Button]
+toButtons = map (\x -> read [x])
+
+-- | Parsers a string wrapped in a color specification.
+colorParser :: FontIndex -> Maybe [Action]
+               -> Parser [(Widget, ColorString, FontIndex, Maybe [Action])]
+colorParser f a = do
+  c <- between (string "<fc=") (string ">") colors
+  s <- manyTill (allParsers c f a) (try $ string "</fc>")
+  return (concat s)
+
+-- | Parsers a string wrapped in a font specification.
+fontParser :: ColorString -> Maybe [Action]
+              -> Parser [(Widget, ColorString, FontIndex, Maybe [Action])]
+fontParser c a = do
+  f <- between (string "<fn=") (string ">") colors
+  s <- manyTill (allParsers c (read f) a) (try $ string "</fn>")
+  return (concat s)
+
+-- | Parses a color specification (hex or named)
+colors :: Parser String
+colors = many1 (alphaNum <|> char ',' <|> char '#')