33 lines
976 B
Haskell
33 lines
976 B
Haskell
module Parsers where
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import Text.ParserCombinators.Parsec
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import Data.Maybe (catMaybes)
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import Data.Char (toUpper)
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import Control.Monad (liftM)
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-- Parsing functions not in Text.ParserCombinators.Parsec
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-- There is also a good ine in hsemail, manyNtoM
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countBetween m n p
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| n < m = error "First bound must be lower or equal than second bound"
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| otherwise = do
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xs <- try (count m p)
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ys <- try (count (n - m) ((option Nothing) (do
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y <- p
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return (Just y))))
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return (xs ++ catMaybes ys)
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facultative p = liftM Just p <|> return Nothing
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-- Case-insensitive parsers stloen from hsemail
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-- Case-insensitive variant of Parsec's 'char' function.
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ichar :: Char -> CharParser st Char
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ichar c = satisfy (\x -> toUpper x == toUpper c)
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-- Case-insensitive variant of Parsec's 'string' function.
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istring :: String -> CharParser st String
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istring cs = mapM ichar cs <?> cs
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--
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-- End of parsing functions
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