mirror of
https://github.com/mrkkrp/megaparsec.git
synced 2024-12-25 09:12:29 +03:00
make combinators more general
Now all the combinators in ‘Text.Megaparsec.Combinator’ are defined for any instance of ‘Control.Alternative’ (sometimes ‘Control.Applicative’). Some combinators are inlined.
This commit is contained in:
parent
4c1858f900
commit
02ebc7ee23
@ -9,7 +9,8 @@
|
|||||||
-- Stability : experimental
|
-- Stability : experimental
|
||||||
-- Portability : portable
|
-- Portability : portable
|
||||||
--
|
--
|
||||||
-- Commonly used generic combinators.
|
-- Commonly used generic combinators. Note that all combinators works with
|
||||||
|
-- any 'Alternative' instances.
|
||||||
|
|
||||||
module Text.Megaparsec.Combinator
|
module Text.Megaparsec.Combinator
|
||||||
( between
|
( between
|
||||||
@ -34,26 +35,25 @@ module Text.Megaparsec.Combinator
|
|||||||
, sepEndBy1 )
|
, sepEndBy1 )
|
||||||
where
|
where
|
||||||
|
|
||||||
import Control.Applicative ((<|>), many, some, optional)
|
import Control.Applicative
|
||||||
import Control.Monad
|
import Control.Monad (void)
|
||||||
import Data.Foldable (asum)
|
import Data.Foldable (asum)
|
||||||
|
|
||||||
import Text.Megaparsec.Prim
|
|
||||||
|
|
||||||
-- | @between open close p@ parses @open@, followed by @p@ and @close@.
|
-- | @between open close p@ parses @open@, followed by @p@ and @close@.
|
||||||
-- Returns the value returned by @p@.
|
-- Returns the value returned by @p@.
|
||||||
--
|
--
|
||||||
-- > braces = between (symbol "{") (symbol "}")
|
-- > braces = between (symbol "{") (symbol "}")
|
||||||
|
|
||||||
between :: Stream s m t => ParsecT s u m open ->
|
between :: Applicative m => m open -> m close -> m a -> m a
|
||||||
ParsecT s u m close -> ParsecT s u m a -> ParsecT s u m a
|
|
||||||
between open close p = open *> p <* close
|
between open close p = open *> p <* close
|
||||||
|
{-# INLINE between #-}
|
||||||
|
|
||||||
-- | @choice ps@ tries to apply the parsers in the list @ps@ in order,
|
-- | @choice ps@ tries to apply the parsers in the list @ps@ in order,
|
||||||
-- until one of them succeeds. Returns the value of the succeeding parser.
|
-- until one of them succeeds. Returns the value of the succeeding parser.
|
||||||
|
|
||||||
choice :: (Foldable f, Stream s m t) => f (ParsecT s u m a) -> ParsecT s u m a
|
choice :: (Foldable f, Alternative m) => f (m a) -> m a
|
||||||
choice = asum
|
choice = asum
|
||||||
|
{-# INLINE choice #-}
|
||||||
|
|
||||||
-- | @count n p@ parses @n@ occurrences of @p@. If @n@ is smaller or
|
-- | @count n p@ parses @n@ occurrences of @p@. If @n@ is smaller or
|
||||||
-- equal to zero, the parser equals to @return []@. Returns a list of @n@
|
-- equal to zero, the parser equals to @return []@. Returns a list of @n@
|
||||||
@ -63,8 +63,9 @@ choice = asum
|
|||||||
--
|
--
|
||||||
-- > count n = count' n n
|
-- > count n = count' n n
|
||||||
|
|
||||||
count :: Stream s m t => Int -> ParsecT s u m a -> ParsecT s u m [a]
|
count :: Alternative m => Int -> m a -> m [a]
|
||||||
count n = count' n n
|
count n = count' n n
|
||||||
|
{-# INLINE count #-}
|
||||||
|
|
||||||
-- | @count\' m n p@ parses from @m@ to @n@ occurrences of @p@. If @n@ is
|
-- | @count\' m n p@ parses from @m@ to @n@ occurrences of @p@. If @n@ is
|
||||||
-- not positive or @m > n@, the parser equals to @return []@. Returns a list
|
-- not positive or @m > n@, the parser equals to @return []@. Returns a list
|
||||||
@ -73,31 +74,29 @@ count n = count' n n
|
|||||||
-- Please note that @m@ /may/ be negative, in this case effect is the same
|
-- Please note that @m@ /may/ be negative, in this case effect is the same
|
||||||
-- as if it were equal to zero.
|
-- as if it were equal to zero.
|
||||||
|
|
||||||
count' :: Stream s m t => Int -> Int -> ParsecT s u m a -> ParsecT s u m [a]
|
count' :: Alternative m => Int -> Int -> m a -> m [a]
|
||||||
count' m n p
|
count' m n p
|
||||||
| n <= 0 || m > n = return []
|
| n <= 0 || m > n = pure []
|
||||||
| m > 0 = (:) <$> p <*> count' (pred m) (pred n) p
|
| m > 0 = (:) <$> p <*> count' (pred m) (pred n) p
|
||||||
| otherwise = do
|
| otherwise =
|
||||||
result <- optional p
|
let f t ts = maybe [] (:ts) t
|
||||||
case result of
|
in f <$> optional p <*> count' 0 (pred n) p
|
||||||
Nothing -> return []
|
|
||||||
Just x -> (x:) <$> count' 0 (pred n) p
|
|
||||||
|
|
||||||
-- | @endBy p sep@ parses /zero/ or more occurrences of @p@, separated
|
-- | @endBy p sep@ parses /zero/ or more occurrences of @p@, separated
|
||||||
-- and ended by @sep@. Returns a list of values returned by @p@.
|
-- and ended by @sep@. Returns a list of values returned by @p@.
|
||||||
--
|
--
|
||||||
-- > cStatements = cStatement `endBy` semicolon
|
-- > cStatements = cStatement `endBy` semicolon
|
||||||
|
|
||||||
endBy :: Stream s m t =>
|
endBy :: Alternative m => m a -> m sep -> m [a]
|
||||||
ParsecT s u m a -> ParsecT s u m sep -> ParsecT s u m [a]
|
|
||||||
endBy p sep = many (p <* sep)
|
endBy p sep = many (p <* sep)
|
||||||
|
{-# INLINE endBy #-}
|
||||||
|
|
||||||
-- | @endBy1 p sep@ parses /one/ or more occurrences of @p@, separated
|
-- | @endBy1 p sep@ parses /one/ or more occurrences of @p@, separated
|
||||||
-- and ended by @sep@. Returns a list of values returned by @p@.
|
-- and ended by @sep@. Returns a list of values returned by @p@.
|
||||||
|
|
||||||
endBy1 :: Stream s m t =>
|
endBy1 :: Alternative m => m a -> m sep -> m [a]
|
||||||
ParsecT s u m a -> ParsecT s u m sep -> ParsecT s u m [a]
|
|
||||||
endBy1 p sep = some (p <* sep)
|
endBy1 p sep = some (p <* sep)
|
||||||
|
{-# INLINE endBy1 #-}
|
||||||
|
|
||||||
-- | @manyTill p end@ applies parser @p@ /zero/ or more times until
|
-- | @manyTill p end@ applies parser @p@ /zero/ or more times until
|
||||||
-- parser @end@ succeeds. Returns the list of values returned by @p@. This
|
-- parser @end@ succeeds. Returns the list of values returned by @p@. This
|
||||||
@ -108,16 +107,16 @@ endBy1 p sep = some (p <* sep)
|
|||||||
-- Note that we need to use 'try' since parsers @anyChar@ and @string
|
-- Note that we need to use 'try' since parsers @anyChar@ and @string
|
||||||
-- \"-->\"@ overlap and @string \"-->\"@ could consume input before failing.
|
-- \"-->\"@ overlap and @string \"-->\"@ could consume input before failing.
|
||||||
|
|
||||||
manyTill :: Stream s m t =>
|
manyTill :: Alternative m => m a -> m end -> m [a]
|
||||||
ParsecT s u m a -> ParsecT s u m end -> ParsecT s u m [a]
|
manyTill p end = (end *> pure []) <|> someTill p end
|
||||||
manyTill p end = (end *> return []) <|> someTill p end
|
{-# INLINE manyTill #-}
|
||||||
|
|
||||||
-- | @someTill p end@ works similarly to @manyTill p end@, but @p@ should
|
-- | @someTill p end@ works similarly to @manyTill p end@, but @p@ should
|
||||||
-- succeed at least once.
|
-- succeed at least once.
|
||||||
|
|
||||||
someTill :: Stream s m t =>
|
someTill :: Alternative m => m a -> m end -> m [a]
|
||||||
ParsecT s u m a -> ParsecT s u m end -> ParsecT s u m [a]
|
|
||||||
someTill p end = (:) <$> p <*> manyTill p end
|
someTill p end = (:) <$> p <*> manyTill p end
|
||||||
|
{-# INLINE someTill #-}
|
||||||
|
|
||||||
-- | @option x p@ tries to apply parser @p@. If @p@ fails without
|
-- | @option x p@ tries to apply parser @p@. If @p@ fails without
|
||||||
-- consuming input, it returns the value @x@, otherwise the value returned
|
-- consuming input, it returns the value @x@, otherwise the value returned
|
||||||
@ -125,38 +124,41 @@ someTill p end = (:) <$> p <*> manyTill p end
|
|||||||
--
|
--
|
||||||
-- > priority = option 0 (digitToInt <$> digitChar)
|
-- > priority = option 0 (digitToInt <$> digitChar)
|
||||||
|
|
||||||
option :: Stream s m t => a -> ParsecT s u m a -> ParsecT s u m a
|
option :: Alternative m => a -> m a -> m a
|
||||||
option x p = p <|> return x
|
option x p = p <|> pure x
|
||||||
|
{-# INLINE option #-}
|
||||||
|
|
||||||
-- | @sepBy p sep@ parses /zero/ or more occurrences of @p@, separated
|
-- | @sepBy p sep@ parses /zero/ or more occurrences of @p@, separated
|
||||||
-- by @sep@. Returns a list of values returned by @p@.
|
-- by @sep@. Returns a list of values returned by @p@.
|
||||||
--
|
--
|
||||||
-- > commaSep p = p `sepBy` comma
|
-- > commaSep p = p `sepBy` comma
|
||||||
|
|
||||||
sepBy :: Stream s m t =>
|
sepBy :: Alternative m => m a -> m sep -> m [a]
|
||||||
ParsecT s u m a -> ParsecT s u m sep -> ParsecT s u m [a]
|
sepBy p sep = sepBy1 p sep <|> pure []
|
||||||
sepBy p sep = sepBy1 p sep <|> return []
|
{-# INLINE sepBy #-}
|
||||||
|
|
||||||
-- | @sepBy1 p sep@ parses /one/ or more occurrences of @p@, separated
|
-- | @sepBy1 p sep@ parses /one/ or more occurrences of @p@, separated
|
||||||
-- by @sep@. Returns a list of values returned by @p@.
|
-- by @sep@. Returns a list of values returned by @p@.
|
||||||
|
|
||||||
sepBy1 :: Stream s m t =>
|
sepBy1 :: Alternative m => m a -> m sep -> m [a]
|
||||||
ParsecT s u m a -> ParsecT s u m sep -> ParsecT s u m [a]
|
|
||||||
sepBy1 p sep = (:) <$> p <*> many (sep *> p)
|
sepBy1 p sep = (:) <$> p <*> many (sep *> p)
|
||||||
|
{-# INLINE sepBy1 #-}
|
||||||
|
|
||||||
-- | @skipMany p@ applies the parser @p@ /zero/ or more times, skipping
|
-- | @skipMany p@ applies the parser @p@ /zero/ or more times, skipping
|
||||||
-- its result.
|
-- its result.
|
||||||
--
|
--
|
||||||
-- > space = skipMany spaceChar
|
-- > space = skipMany spaceChar
|
||||||
|
|
||||||
skipMany :: ParsecT s u m a -> ParsecT s u m ()
|
skipMany :: Alternative m => m a -> m ()
|
||||||
skipMany p = void $ many p
|
skipMany p = void $ many p
|
||||||
|
{-# INLINE skipMany #-}
|
||||||
|
|
||||||
-- | @skipSome p@ applies the parser @p@ /one/ or more times, skipping
|
-- | @skipSome p@ applies the parser @p@ /one/ or more times, skipping
|
||||||
-- its result.
|
-- its result.
|
||||||
|
|
||||||
skipSome :: Stream s m t => ParsecT s u m a -> ParsecT s u m ()
|
skipSome :: Alternative m => m a -> m ()
|
||||||
skipSome p = void $ some p
|
skipSome p = void $ some p
|
||||||
|
{-# INLINE skipSome #-}
|
||||||
|
|
||||||
-- Deprecated combinators
|
-- Deprecated combinators
|
||||||
|
|
||||||
@ -167,9 +169,9 @@ skipSome p = void $ some p
|
|||||||
|
|
||||||
{-# DEPRECATED chainl "Use \"Text.Megaparsec.Expr\" instead." #-}
|
{-# DEPRECATED chainl "Use \"Text.Megaparsec.Expr\" instead." #-}
|
||||||
|
|
||||||
chainl :: Stream s m t =>
|
chainl :: Alternative m => m a -> m (a -> a -> a) -> a -> m a
|
||||||
ParsecT s u m a -> ParsecT s u m (a -> a -> a) -> a -> ParsecT s u m a
|
chainl p op x = chainl1 p op <|> pure x
|
||||||
chainl p op x = chainl1 p op <|> return x
|
{-# INLINE chainl #-}
|
||||||
|
|
||||||
-- | @chainl1 p op@ parses /one/ or more occurrences of @p@,
|
-- | @chainl1 p op@ parses /one/ or more occurrences of @p@,
|
||||||
-- separated by @op@ Returns a value obtained by a /left/ associative
|
-- separated by @op@ Returns a value obtained by a /left/ associative
|
||||||
@ -181,10 +183,11 @@ chainl p op x = chainl1 p op <|> return x
|
|||||||
|
|
||||||
{-# DEPRECATED chainl1 "Use \"Text.Megaparsec.Expr\" instead." #-}
|
{-# DEPRECATED chainl1 "Use \"Text.Megaparsec.Expr\" instead." #-}
|
||||||
|
|
||||||
chainl1 :: Stream s m t =>
|
chainl1 :: Alternative m => m a -> m (a -> a -> a) -> m a
|
||||||
ParsecT s u m a -> ParsecT s u m (a -> a -> a) -> ParsecT s u m a
|
chainl1 p op = scan
|
||||||
chainl1 p op = p >>= rest
|
where scan = flip id <$> p <*> rst
|
||||||
where rest x = ((($ x) <$> op <*> p) >>= rest) <|> return x
|
rst = (\f y g x -> g (f x y)) <$> op <*> p <*> rst <|> pure id
|
||||||
|
{-# INLINE chainl1 #-}
|
||||||
|
|
||||||
-- | @chainr p op x@ parses /zero/ or more occurrences of @p@,
|
-- | @chainr p op x@ parses /zero/ or more occurrences of @p@,
|
||||||
-- separated by @op@ Returns a value obtained by a /right/ associative
|
-- separated by @op@ Returns a value obtained by a /right/ associative
|
||||||
@ -195,9 +198,9 @@ chainl1 p op = p >>= rest
|
|||||||
|
|
||||||
{-# DEPRECATED chainr "Use \"Text.Megaparsec.Expr\" instead." #-}
|
{-# DEPRECATED chainr "Use \"Text.Megaparsec.Expr\" instead." #-}
|
||||||
|
|
||||||
chainr :: Stream s m t =>
|
chainr :: Alternative m => m a -> m (a -> a -> a) -> a -> m a
|
||||||
ParsecT s u m a -> ParsecT s u m (a -> a -> a) -> a -> ParsecT s u m a
|
chainr p op x = chainr1 p op <|> pure x
|
||||||
chainr p op x = chainr1 p op <|> return x
|
{-# INLINE chainr #-}
|
||||||
|
|
||||||
-- | @chainr1 p op@ parses /one/ or more occurrences of |p|,
|
-- | @chainr1 p op@ parses /one/ or more occurrences of |p|,
|
||||||
-- separated by @op@ Returns a value obtained by a /right/ associative
|
-- separated by @op@ Returns a value obtained by a /right/ associative
|
||||||
@ -208,10 +211,11 @@ chainr p op x = chainr1 p op <|> return x
|
|||||||
|
|
||||||
{-# DEPRECATED chainr1 "Use \"Text.Megaparsec.Expr\" instead." #-}
|
{-# DEPRECATED chainr1 "Use \"Text.Megaparsec.Expr\" instead." #-}
|
||||||
|
|
||||||
chainr1 :: Stream s m t =>
|
chainr1 :: Alternative m => m a -> m (a -> a -> a) -> m a
|
||||||
ParsecT s u m a -> ParsecT s u m (a -> a -> a) -> ParsecT s u m a
|
chainr1 p op = scan where
|
||||||
chainr1 p op = p >>= rest
|
scan = flip id <$> p <*> rst
|
||||||
where rest x = (($ x) <$> op <*> chainr1 p op) <|> return x
|
rst = (flip <$> op <*> scan) <|> pure id
|
||||||
|
{-# INLINE chainr1 #-}
|
||||||
|
|
||||||
-- | @sepEndBy p sep@ parses /zero/ or more occurrences of @p@,
|
-- | @sepEndBy p sep@ parses /zero/ or more occurrences of @p@,
|
||||||
-- separated and optionally ended by @sep@. Returns a list of values
|
-- separated and optionally ended by @sep@. Returns a list of values
|
||||||
@ -219,9 +223,9 @@ chainr1 p op = p >>= rest
|
|||||||
|
|
||||||
{-# DEPRECATED sepEndBy "Use @sepBy p sep <* optional sep@ instead." #-}
|
{-# DEPRECATED sepEndBy "Use @sepBy p sep <* optional sep@ instead." #-}
|
||||||
|
|
||||||
sepEndBy :: Stream s m t =>
|
sepEndBy :: Alternative m => m a -> m sep -> m [a]
|
||||||
ParsecT s u m a -> ParsecT s u m sep -> ParsecT s u m [a]
|
|
||||||
sepEndBy p sep = sepBy p sep <* optional sep
|
sepEndBy p sep = sepBy p sep <* optional sep
|
||||||
|
{-# INLINE sepEndBy #-}
|
||||||
|
|
||||||
-- | @sepEndBy1 p sep@ parses /one/ or more occurrences of @p@,
|
-- | @sepEndBy1 p sep@ parses /one/ or more occurrences of @p@,
|
||||||
-- separated and optionally ended by @sep@. Returns a list of values
|
-- separated and optionally ended by @sep@. Returns a list of values
|
||||||
@ -229,6 +233,6 @@ sepEndBy p sep = sepBy p sep <* optional sep
|
|||||||
|
|
||||||
{-# DEPRECATED sepEndBy1 "Use @sepBy1 p sep <* optional sep@ instead." #-}
|
{-# DEPRECATED sepEndBy1 "Use @sepBy1 p sep <* optional sep@ instead." #-}
|
||||||
|
|
||||||
sepEndBy1 :: Stream s m t =>
|
sepEndBy1 :: Alternative m => m a -> m sep -> m [a]
|
||||||
ParsecT s u m a -> ParsecT s u m sep -> ParsecT s u m [a]
|
|
||||||
sepEndBy1 p sep = sepBy1 p sep <* optional sep
|
sepEndBy1 p sep = sepBy1 p sep <* optional sep
|
||||||
|
{-# INLINE sepEndBy1 #-}
|
||||||
|
Loading…
Reference in New Issue
Block a user