Text.Parsing.Parser

data ParseError

A parsing error, consisting of a message and position information.

Constructors

• ParseError String Position

Instances

• Show ParseError
• Eq ParseError
• Ord ParseError
• (Monad m) => MonadThrow ParseError (ParserT s m)
• (Monad m) => MonadError ParseError (ParserT s m)

parseErrorMessage :: ParseError -> String

parseErrorPosition :: ParseError -> Position

data ParseState s

Contains the remaining input and current position.

Constructors

• ParseState s Position Boolean

Instances

• (Monad m) => MonadState (ParseState s) (ParserT s m)

newtype ParserT s m a

The Parser monad transformer.

The first type argument is the stream type. Typically, this is either String, or some sort of token stream.

Constructors

• ParserT (ExceptT ParseError (StateT (ParseState s) m) a)

Instances

• Newtype (ParserT s m a) _
• Lazy (ParserT s m a)
• (Monad m, Semigroup a) => Semigroup (ParserT s m a)
• (Monad m, Monoid a) => Monoid (ParserT s m a)
• (Functor m) => Functor (ParserT s m)
• (Monad m) => Apply (ParserT s m)
• (Monad m) => Applicative (ParserT s m)
• (Monad m) => Bind (ParserT s m)
• (Monad m) => Monad (ParserT s m)
• (MonadRec m) => MonadRec (ParserT s m)
• (Monad m) => MonadState (ParseState s) (ParserT s m)
• (Monad m) => MonadThrow ParseError (ParserT s m)
• (Monad m) => MonadError ParseError (ParserT s m)
• (Monad m) => Alt (ParserT s m)
• (Monad m) => Plus (ParserT s m)
• (Monad m) => Alternative (ParserT s m)
• (Monad m) => MonadZero (ParserT s m)
• (Monad m) => MonadPlus (ParserT s m)
• MonadTrans (ParserT s)

type Parser s = ParserT s Identity

The Parser monad is a synonym for the parser monad transformer applied to the Identity monad.

runParser :: forall s a. s -> Parser s a -> Either ParseError a

Apply a parser, keeping only the parsed result.

runParserT :: forall m s a. Monad m => s -> ParserT s m a -> m (Either ParseError a)

Apply a parser, keeping only the parsed result.

hoistParserT :: forall s m n a. (m ~> n) -> ParserT s m a -> ParserT s n a

mapParserT :: forall b n s a m. (m (Tuple (Either ParseError a) (ParseState s)) -> n (Tuple (Either ParseError b) (ParseState s))) -> ParserT s m a -> ParserT s n b

Change the underlying monad action and data type in a ParserT monad action.

consume :: forall s m. Monad m => ParserT s m Unit

Set the consumed flag.

position :: forall s m. Monad m => ParserT s m Position

Returns the current position in the stream.

fail :: forall m s a. Monad m => String -> ParserT s m a

Fail with a message.

failWithPosition :: forall m s a. Monad m => String -> Position -> ParserT s m a

Fail with a message and a position.

region :: forall m s a. Monad m => (ParseError -> ParseError) -> ParserT s m a -> ParserT s m a

Contextualize parsing failures inside a region. If a parsing failure occurs, then the ParseError will be transformed by each containing region as the parser backs out the call stack.