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+{-
+Copyright (C) 2006-7 John MacFarlane <jgm@berkeley.edu>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+-}
+
+{- |
+ Module : Text.Pandoc.ParserCombinators
+ Copyright : Copyright (C) 2006-7 John MacFarlane
+ License : GNU GPL, version 2 or above
+
+ Maintainer : John MacFarlane <jgm@berkeley.edu>
+ Stability : alpha
+ Portability : portable
+
+Parser combinators used in Pandoc readers.
+-}
+module Text.Pandoc.ParserCombinators (
+ anyLine,
+ many1Till,
+ notFollowedBy',
+ oneOfStrings,
+ spaceChar,
+ skipSpaces,
+ blankline,
+ blanklines,
+ enclosed,
+ stringAnyCase,
+ parseFromStr,
+ lineClump
+ ) where
+import Text.ParserCombinators.Parsec
+import Data.Char ( toUpper, toLower )
+
+--- | Parse any line of text
+anyLine :: GenParser Char st [Char]
+anyLine = try (manyTill anyChar newline) <|> many1 anyChar
+ -- second alternative is for a line ending with eof
+
+-- | Parses a space or tab.
+spaceChar :: CharParser st Char
+spaceChar = oneOf " \t"
+
+-- | Skips zero or more spaces or tabs.
+skipSpaces :: GenParser Char st ()
+skipSpaces = skipMany spaceChar
+
+-- | Skips zero or more spaces or tabs, then reads a newline.
+blankline :: GenParser Char st Char
+blankline = try (do
+ skipSpaces
+ newline)
+
+-- | Parses one or more blank lines and returns a string of newlines.
+blanklines :: GenParser Char st [Char]
+blanklines = try (many1 blankline)
+
+-- | Parses material enclosed between start and end parsers.
+enclosed :: GenParser Char st t -- ^ start parser
+ -> GenParser Char st end -- ^ end parser
+ -> GenParser Char st a -- ^ content parser (to be used repeatedly)
+ -> GenParser Char st [a]
+enclosed start end parser = try (do
+ start
+ notFollowedBy space
+ result <- many1Till parser end
+ return result)
+
+-- | Like @manyTill@, but reads at least one item.
+many1Till :: GenParser tok st a
+ -> GenParser tok st end
+ -> GenParser tok st [a]
+many1Till p end = try (do
+ first <- p
+ rest <- manyTill p end
+ return (first:rest))
+
+-- | A more general form of @notFollowedBy@. This one allows any
+-- type of parser to be specified, and succeeds only if that parser fails.
+-- It does not consume any input.
+notFollowedBy' :: Show b => GenParser a st b -> GenParser a st ()
+notFollowedBy' parser = try (do { c <- try parser; unexpected (show c) }
+ <|> return ())
+
+-- | Parses one of a list of strings (tried in order).
+oneOfStrings :: [String] -> GenParser Char st String
+oneOfStrings listOfStrings = choice $ map (try . string) listOfStrings
+
+-- | Parse string, case insensitive.
+stringAnyCase :: [Char] -> CharParser st String
+stringAnyCase [] = string ""
+stringAnyCase (x:xs) = try (do
+ firstChar <- choice [ char (toUpper x), char (toLower x) ]
+ rest <- stringAnyCase xs
+ return (firstChar:rest))
+
+-- | Parse contents of 'str' using 'parser' and return result.
+parseFromStr :: GenParser tok st a -> [tok] -> GenParser tok st a
+parseFromStr parser str = try $ do
+ oldInput <- getInput
+ setInput str
+ result <- parser
+ setInput oldInput
+ return result
+
+-- | Parse raw line block up to and including blank lines.
+lineClump :: GenParser Char st String
+lineClump = do
+ lines <- many1 (do{notFollowedBy blankline; anyLine})
+ blanks <- blanklines <|> (do{eof; return "\n"})
+ return ((unlines lines) ++ blanks)
+