Safe Haskell	Safe
Language	Haskell98

Text.Lexer.Inchworm.Source

Synopsis

data Source m loc input = Source {
- sourceSkip :: (Elem input -> Bool) -> m ()
- sourceTry :: forall a. m (Maybe a) -> m (Maybe a)
- sourcePull :: (Elem input -> Bool) -> m (Maybe (Range loc, Elem input))
- sourcePulls :: forall s. Maybe Int -> (Int -> Elem input -> s -> Maybe s) -> s -> m (Maybe (Range loc, input))
- sourceBumpLoc :: Elem input -> loc -> loc
- sourceRemaining :: m (loc, input)
}
data Range loc = Range !loc !loc
data Location = Location !Int !Int
class Sequence is where
- type Elem is
- length :: is -> Int
makeListSourceIO :: forall i loc. Eq i => loc -> (i -> loc -> loc) -> [i] -> IO (Source IO loc [i])

Documentation

data Source m loc input Source #

An abstract source of input tokens that we want to perform lexical analysis on.

Each token is associated with a source location loc. A a sequence of tokens has type input, and a single token type (Elem input).

Constructors

Fields

sourceSkip :: (Elem input -> Bool) -> m ()
Skip over values from the source that match the given predicate.
sourceTry :: forall a. m (Maybe a) -> m (Maybe a)
Try to evaluate the given computation that may pull values from the source. If it returns Nothing then rewind the source to the original position.
sourcePull :: (Elem input -> Bool) -> m (Maybe (Range loc, Elem input))
Pull a value from the source, provided it matches the given predicate. In the result we get the location if the first and final element tha matched.
sourcePulls :: forall s. Maybe Int -> (Int -> Elem input -> s -> Maybe s) -> s -> m (Maybe (Range loc, input))
Use a fold function to select a some consecutive tokens from the source that we want to process, also passing the current index to the fold function.
The maximum number of tokens to select is set by the first argument, which can be set to Nothing for no maximum.
In the result we get the location of the first and final element that matched.
sourceBumpLoc :: Elem input -> loc -> loc
Bump the source location using the given element.
sourceRemaining :: m (loc, input)
Get the remaining input.

A range of locations in a source file.

Constructors

Range !loc !loc

Instances

Show loc => Show (Range loc) Source #
Instance details Defined in Text.Lexer.Inchworm.Source Methods showsPrec :: Int -> Range loc -> ShowS # show :: Range loc -> String # showList :: [Range loc] -> ShowS #

A location in a source file.

Constructors

Instances

Show Location Source #
Instance details Defined in Text.Lexer.Inchworm.Source Methods showsPrec :: Int -> Location -> ShowS # show :: Location -> String # showList :: [Location] -> ShowS #

class Sequence is where Source #

Class of sequences of things.

Associated Types

An element of a sequence.

Methods

Yield the length of a sequence.

Instances

Sequence [a] Source #
Instance details Defined in Text.Lexer.Inchworm.Source Associated Types type Elem [a] :: Type Source # Methods length :: [a] -> Int Source #

Arguments

:: Eq i
=> loc	Starting source location.
-> (i -> loc -> loc)	Function to bump the current location by one input token.
-> [i]	List of input tokens.
-> IO (Source IO loc [i])

Make a source from a list of input tokens, maintaining the state in the IO monad.