Text.Regex.PDeriv.RE

Documentation

data RE

data type of the regular expresions

Constructors

Phi

Empty

an empty exp

L Char

a literal / a character

Choice RE RE GFlag

a choice exp 'r1 + r2'

Seq RE RE

a pair exp '(r1,r2)'

Star RE GFlag

a kleene's star exp 'r*'

Any

.

Not [Char]

excluding characters e.g. [^abc]

Instances

Eq RE

the eq instance

Show RE

A pretty printing function for regular expression

Key RE

IsGreedy RE

Simplifiable RE

IsPhi RE

IsEpsilon RE

function isEpsilon checks whether epsilon = r

PosEpsilon RE

resToRE :: [RE] -> RE

function resToRE sums up a list of regular expressions with the choice operation.

partDeriv :: RE -> Char -> [RE]

function partDeriv implements the partial derivative operations for regular expressions. We don't pay attention to the greediness flag here.

sigmaRE :: RE -> [Char]

function sigmaRE returns all characters appearing in a reg exp.