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GHC 10.0.0.20260917 · lts/ghc-10.0.x · 77a8662 · 2026-10-31

Modulederp-0.1.6Haskell98

Text.Derp

Contents

Data Types
Parser construction
Parser computation steps
Full parsing and result extraction
Demos

Synopsis

Packagederp-0.1.6
Exports33
LanguageHaskell98
LicenceBSD-3-Clause
SourceDerp.hs

Data Types

datadata Parser t a

Represents both a formal context-free language and the reduction of a member of that language to a value of type a.

Instances1Show

Show (Parser t a)Defined in derp-0.1.6 · Text.Derp

datadata Token t

Constructors

Token
- tokenClass :: t
- tokenValue :: String

Instances3Eq, Ord, Show

Eq t => Eq (Token t)Defined in derp-0.1.6 · Text.Derp
Ord t => Ord (Token t)Defined in derp-0.1.6 · Text.Derp
Show t => Show (Token t)Defined in derp-0.1.6 · Text.Derp

Parser construction

value(<|>) :: (Ord t, Ord a) => Parser t a -> Parser t a -> Parser t a

Alternation.

value(<~>)

:: (Ord t, Ord a, Ord b)
=> Parser t a
-> Parser t b
-> Parser t (a, b)

Concatenation.

value(==>) :: (Ord t, Ord a, Ord b) => Parser t a -> (a -> b) -> Parser t b

Reduction.

valuenul :: (Ord t, Ord a) => Parser t a -> Parser t a

Null-parse extraction.

valueter :: Ord t => t -> Parser t String

Terminal.

valueeps :: (Ord t, Ord a) => a -> Parser t a

Epsilon/empty-string.

valueemp :: (Ord t, Ord a) => Parser t a

The empty language.

Parser computation steps

valuederive :: Parser t a -> Token t -> Parser t a

The main derivative function.

valuecompact :: Parser t a -> Parser t a

The optimization step of the algorithm.

valueparseNull :: (Ord t, Ord a) => Parser t a -> Set a

Extract the parse-null set of a parser.

Full parsing and result extraction

valuedefaultCompactSteps :: Int

The number of compact steps that usually keeps a parser constant in size while parsing.

valuecompactNum :: Int -> Parser t a -> Parser t a

A specified number of compactions.

valuederiveStepNum :: Int -> Parser t a -> Token t -> Parser t a

Derivation followed by a specified number of compactions.

valuerunParseNum :: (Ord t, Ord a) => Int -> Parser t a -> [Token t] -> Set a

Parse using a specified number of intermediate compactions.

valuerunParseStagesNum

:: (Ord t, Ord a)
=> Int
-> Parser t a
-> [Token t]
-> [(Parser t a, Set a, [Token t])]

valuerunParseStages

:: (Ord t, Ord a)
=> Parser t a
-> [Token t]
-> [(Parser t a, Set a, [Token t])]

valuerunParseLongestMatchNum

:: (Ord t, Ord a)
=> Int
-> Parser t a
-> [Token t]
-> Maybe (Int, Set a, [Token t])

valuerunParseLongestMatch

:: (Ord t, Ord a)
=> Parser t a
-> [Token t]
-> Maybe (Int, Set a, [Token t])

valuederiveStep :: Parser t a -> Token t -> Parser t a

Derivation followed by the default number of compactions.

valuerunParse :: (Ord t, Ord a) => Parser t a -> [Token t] -> Set a

Parse using the default number of intermediate compactions. This is the main parsing function. Examples:

let e =     ter "num"
        <|> e <~> ter "+" <~> e ==> (\(x1,(o,x2)) -> "(" ++ x1 ++ o ++ x2 ++ ")")
in runParse e [Token "num" "1", Token "+" "+", Token "num" 3", Token "+" "+", Token "num" "5"]

evaluates to:

Set.fromList ["((1+3)+5)", "(1+(3+5))"]

let e =     ter "num" ==> read 
        <|> e <~> ter "+" <~> e ==> (\(x1,(_,x2)) -> x1 + x2)
in runParse e [Token "num" "1", Token "+" "+", Token "num" 3", Token "+" "+", Token "num" "5"]

evaluates to:

Set.fromList [9]

Demos

valuexsR :: () -> Parser String String

valuexsL :: () -> Parser String String

valuexsIn :: [Token String]

valueparens :: () -> Parser String String

valueparensIn :: [Token String]

valueamb :: () -> Parser String String

valueambIn :: [Token String]

valuesexp :: () -> Parser String String

valuesexpIn :: [Token String]

valuesomeStuff :: [Token String]

valuesomeStuffG :: () -> Parser String String