SimpleParser.Parser

ParserT is the core monad transformer for parsing.

Documentation

newtype ParserT l s e m a

A ParserT is a stateerrorlist transformer useful for parsing. All MTL instances are for this transformer only. If, for example, your effect has its own MonadState instance, you'll have to use 'lift get' instead of get.

Constructors

ParserT

Fields

• runParserT :: s -> m (Maybe (ParseResult l s e a))

Instances

Monad m => MonadError e (ParserT l s e m)

Defined in SimpleParser.Parser

Methods

throwError :: e -> ParserT l s e m a

catchError :: ParserT l s e m a -> (e -> ParserT l s e m a) -> ParserT l s e m a

Monad m => MonadState s (ParserT l s e m)

Defined in SimpleParser.Parser

Methods

get :: ParserT l s e m s

put :: s -> ParserT l s e m ()

state :: (s -> (a, s)) -> ParserT l s e m a

MFunctor (ParserT l s e :: (Type -> Type) -> Type -> Type)

Defined in SimpleParser.Parser

Methods

hoist :: forall m n (b :: k). Monad m => (forall a. m a -> n a) -> ParserT l s e m b -> ParserT l s e n b

MonadTrans (ParserT l s e)

Defined in SimpleParser.Parser

Methods

lift :: Monad m => m a -> ParserT l s e m a

Monad m => Monad (ParserT l s e m)

Defined in SimpleParser.Parser

Methods

(>>=) :: ParserT l s e m a -> (a -> ParserT l s e m b) -> ParserT l s e m b

(>>) :: ParserT l s e m a -> ParserT l s e m b -> ParserT l s e m b

return :: a -> ParserT l s e m a

Functor m => Functor (ParserT l s e m)

Defined in SimpleParser.Parser

Methods

fmap :: (a -> b) -> ParserT l s e m a -> ParserT l s e m b

(<$) :: a -> ParserT l s e m b -> ParserT l s e m a

Monad m => MonadFail (ParserT l s e m)

Defined in SimpleParser.Parser

Methods

fail :: String -> ParserT l s e m a

Monad m => Applicative (ParserT l s e m)

Defined in SimpleParser.Parser

Methods

pure :: a -> ParserT l s e m a

(<*>) :: ParserT l s e m (a -> b) -> ParserT l s e m a -> ParserT l s e m b

liftA2 :: (a -> b -> c) -> ParserT l s e m a -> ParserT l s e m b -> ParserT l s e m c

(*>) :: ParserT l s e m a -> ParserT l s e m b -> ParserT l s e m b

(<*) :: ParserT l s e m a -> ParserT l s e m b -> ParserT l s e m a

Monad m => Alternative (ParserT l s e m)

Defined in SimpleParser.Parser

Methods

empty :: ParserT l s e m a

(<|>) :: ParserT l s e m a -> ParserT l s e m a -> ParserT l s e m a

some :: ParserT l s e m a -> ParserT l s e m [a]

many :: ParserT l s e m a -> ParserT l s e m [a]

Monad m => MonadPlus (ParserT l s e m)

Defined in SimpleParser.Parser

Methods

mzero :: ParserT l s e m a

mplus :: ParserT l s e m a -> ParserT l s e m a -> ParserT l s e m a

type Parser l s e a = ParserT l s e Identity a

Use Parser if you have no need for other monadic effects.

runParser :: Parser l s e a -> s -> Maybe (ParseResult l s e a)

Runs a non-effectful parser from an inital state and collects all results.

pureParser :: Monad m => a -> ParserT l s e m a

Applicative pure

bindParser :: Monad m => ParserT l s e m a -> (a -> ParserT l s e m b) -> ParserT l s e m b

Monadic bind

failParser :: Monad m => Text -> ParserT l s e m a

A simple failing parser

liftParser :: Monad m => m a -> ParserT l s e m a

hoistParser :: (forall x. m x -> n x) -> ParserT l s e m a -> ParserT l s e n a

catchJustParser :: Monad m => (e -> Maybe b) -> ParserT l s e m a -> (b -> ParserT l s e m a) -> ParserT l s e m a

Catch only a subset of custom errors. This preserves label information vs rethrowing.

throwParser :: Monad m => e -> ParserT l s e m a

Throws a custom error

catchParser :: Monad m => ParserT l s e m a -> (e -> ParserT l s e m a) -> ParserT l s e m a

Catches a custom error

emptyParser :: Monad m => ParserT l s e m a

The empty parser

orParser :: Monad m => ParserT l s e m a -> ParserT l s e m a -> ParserT l s e m a

Yields from the first parser of the two that returns a successfull result. Otherwise will merge and yield all errors.

greedyStarParser :: (Chunked seq elem, Monad m) => ParserT l s e m elem -> ParserT l s e m seq

Yields the LONGEST string of 0 or more successes of the given parser. Failures will be silenced.

greedyStarParser_ :: Monad m => ParserT l s e m a -> ParserT l s e m ()

Same as greedyStarParser but discards the result.

greedyPlusParser :: (Chunked seq elem, Monad m) => ParserT l s e m elem -> ParserT l s e m seq

Yields the LONGEST string of 1 or more successes of the given parser. Failures in the tail will be silenced, but those in the head will be returned.

greedyPlusParser_ :: Monad m => ParserT l s e m a -> ParserT l s e m ()

Same as greedyPlusParser but discards the result.

defaultParser :: Monad m => a -> ParserT l s e m a -> ParserT l s e m a

If the parser does not succeed, yield the given value.

optionalParser :: Monad m => ParserT l s e m a -> ParserT l s e m (Maybe a)

A parser that yields Nothing if the parser does not succeed, otherwise wraps success in Just.

reflectParser :: Monad m => ParserT l s e m a -> ParserT l s e m (Maybe (ParseResult l s e a))

Run the parser speculatively and return results. Does not advance state or throw errors.

silenceParser :: Monad m => ParserT l s e m a -> ParserT l s e m a

Removes all failures from the parse results. Catches more errors than 'catchError (const empty)' because this includes stream errors, not just custom errors. If you want more fine-grained control, use reflectParser and map over the results.

lookAheadParser :: Monad m => ParserT l s e m a -> ParserT l s e m a

Yield the results of the given parser, but rewind back to the starting state. Note that these results may contain errors, so you may want to stifle them with silenceParser, for example.

markParser :: Monad m => Maybe l -> ParserT l s e m a -> ParserT l s e m a

Push the label and current state onto the parse error mark stack. Useful to delimit named sub-spans for error reporting.

markWithStateParser :: Monad m => Maybe l -> (s -> (b, s)) -> (b -> ParserT l s e m a) -> ParserT l s e m a

Like markParser but allows you to mutate state. See withToken and withChunk.

markWithOptStateParser :: Monad m => Maybe l -> (s -> Maybe (b, s)) -> (Maybe b -> ParserT l s e m a) -> ParserT l s e m a

Like markParser but allows you to mutate state. See withToken and withChunk.

unmarkParser :: Monad m => ParserT l s e m a -> ParserT l s e m a

Clear marks from parse errors. You can mark immediately after to widen the narrowest marked span to the range you want to report.

commitParser :: Monad m => ParserT l s e m () -> ParserT l s e m a -> ParserT l s e m a

If the first parser succeeds in the initial state, yield results from the second parser in the initial state. This is likely the look-ahead you want, since errors from the first parser are completely ignored. Use the first parser to check a prefix of input, and use the second to consume that input.

onEmptyParser :: Parser l s e a -> Parser l s e a -> Parser l s e a

If the first parser yields NO results (success or failure), yield from the second. Note that this is different from orParser in that it does not try the second if there are errors in the first. You might use this on the outside of a complex parser with a fallback to fail to indicate that there are no matches.