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implementation module Yard
import StdTuple
import StdClass
import StdString
import StdList
import StdInt
import Common
concat :: ([String] -> String)
concat = foldl (+++) ""
intersperse :: !a ![a] -> [a]
intersperse i [] = []
intersperse i [x] = [x]
intersperse i [x:xs] = [x,i:intersperse i xs]
runParser :: (Parser a b) [a] -> (Either Error b, [a])
runParser (Parser f) i = f i
instance Functor (Parser a) where
(<$>) f m = m >>= \x -> pure (f x)
instance Applicative (Parser a) where
pure a = Parser \i -> (Right a, i)
(<*>) sf p = sf >>= \sf` -> p >>= \p` -> pure (sf` p`)
instance Monad (Parser a) where
(>>=) p f = Parser \i -> case runParser p i of
(Right r, rest) = runParser (f r) rest
(Left e, _) = (Left e, i)
instance Alternative (Parser a) where
empty = Parser \i -> (Left $ GenericError "" , i)
(<|>) p1 p2 = Parser \i -> case runParser p1 i of
(Right r, rest) = (Right r, rest)
(Left e1, rest) = case runParser p2 i of
(Left e2, rest) = (Left e2, i)
(Right r, rest) = (Right r, rest)
(<?>) :: (Parser a b) Error -> Parser a b
(<?>) p e = Parser \i -> case runParser p i of
(Left e1, rest) = (Left e, rest)
(Right r, rest) = (Right r, rest)
fail :: Parser a b
fail = empty
top :: Parser a a
top = Parser \i -> case i of
[] = (Left $ GenericError "", [])
[x:xs] = (Right x, xs)
peek :: Parser a a
peek = Parser \i -> case i of
[] = (Left $ GenericError "", [])
[x:xs] = (Right x, [x:xs])
(until) infix 2 :: (Parser a b) (Parser a c) -> Parser a [b]
(until) p guard = try $ until` p guard []
where
until` :: (Parser a b) (Parser a c) [b] -> Parser a [b]
until` p guard acc = Parser \i -> case runParser guard i of
(Right _, rest) = (Right acc, rest)
(Left _, _) = case runParser p i of
(Right r, rest) = runParser (until` p guard [r:acc]) rest
(Left e, _) = (Left e, i)
try :: (Parser a b) -> Parser a b
try p = Parser \i -> case runParser p i of
(Left e, _) = (Left e, i)
(Right r, rest) = (Right r, rest)
satisfy :: (a -> Bool) -> Parser a a
satisfy f = top >>= \r -> if (f r) (pure r) fail
check :: (a -> Bool) -> Parser a a
check f = peek >>= \r -> if (f r) (pure r) fail
item :: a -> Parser a a | == a
item a = satisfy ((==)a)
list :: [a] -> Parser a [a] | == a
list as = mapM item as
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