Text.RE.TDFA

Tutorial

We have a regex tutorial at http://tutorial.regex.uk.

About this Module

This module provides access to the back end through polymorphic functions that operate over all of the String/Text/ByteString types supported by the back end. If you don't need this generality then you might want to consider using one of the modules that have been specialised for each of these types:

• Text.RE.TDFA.ByteString
• Text.RE.TDFA.ByteString.Lazy
• Text.RE.ZeInternals.TDFA
• Text.RE.TDFA.Sequence
• Text.RE.TDFA.String
• Text.RE.TDFA.Text
• Text.RE.TDFA.Text.Lazy

The Match Operators

(*=~) :: IsRegex RE s => s -> RE -> Matches s

find all the matches in the argument text; e.g., to count the number of naturals in s:

countMatches $ s *=~ [re|[0-9]+|]

(?=~) :: IsRegex RE s => s -> RE -> Match s

find the first match in the argument text; e.g., to test if there is a natural number in the input text:

matched $ s ?=~ [re|[0-9]+|]

The SearchReplace Operators

(*=~/) :: IsRegex RE s => s -> SearchReplace RE s -> s

search and replace all matches in the argument text; e.g., this section will convert every YYYY-MM-DD format date in its argument text into a DD/MM/YYYY date:

(*=~/ [ed|${y}([0-9]{4})-0*${m}([0-9]{2})-0*${d}([0-9]{2})///${d}/${m}/${y}|])

(?=~/) :: IsRegex RE s => s -> SearchReplace RE s -> s

search and replace the first occurrence only

Matches

data Matches a

the result type to use when every match is needed, not just the first match of the RE against the source

Instances

Functor Matches

Methods

fmap :: (a -> b) -> Matches a -> Matches b

(<$) :: a -> Matches b -> Matches a

(RegexContext regex source [MatchText source], RegexLike regex source) => RegexContext regex source (Matches source)

this instance hooks Matches into regex-base: regex consumers need not worry about any of this

Methods

match :: regex -> source -> Matches source

matchM :: Monad m => regex -> source -> m (Matches source)

Eq a => Eq (Matches a)

Methods

(==) :: Matches a -> Matches a -> Bool

(/=) :: Matches a -> Matches a -> Bool

Show a => Show (Matches a)

Methods

showsPrec :: Int -> Matches a -> ShowS

show :: Matches a -> String

showList :: [Matches a] -> ShowS

matchesSource :: Matches a -> a

the source text being matched

allMatches :: Matches a -> [Match a]

all Match instances found, left to right

anyMatches :: Matches a -> Bool

tests whether the RE matched the source text at all

countMatches :: Matches a -> Int

count the matches

matches :: Matches a -> [a]

list the Matches

Match

data Match a

the result of matching a RE to a text once, listing the text that was matched and the named captures in the RE and all of the substrings matched, with the text captured by the whole RE; a complete failure to match will be represented with an empty array (with bounds (0,-1))

Instances

Functor Match

Methods

fmap :: (a -> b) -> Match a -> Match b

(<$) :: a -> Match b -> Match a

(RegexContext regex source (AllTextSubmatches (Array Int) (source, (Int, Int))), RegexLike regex source) => RegexContext regex source (Match source)

this instance hooks Match into regex-base: regex consumers need not worry about any of this

Methods

match :: regex -> source -> Match source

matchM :: Monad m => regex -> source -> m (Match source)

Eq a => Eq (Match a)

Methods

(==) :: Match a -> Match a -> Bool

(/=) :: Match a -> Match a -> Bool

Show a => Show (Match a)

Methods

showsPrec :: Int -> Match a -> ShowS

show :: Match a -> String

showList :: [Match a] -> ShowS

matchSource :: Match a -> a

the whole source text

matched :: Match a -> Bool

tests whether the RE matched the source text at all

matchedText :: Match a -> Maybe a

tests whether the RE matched the source text at all

The RE Type

data RE

the RE type for this back end representing a well-formed, compiled RE

Instances

IsOption REOptions RE CompOption ExecOption

Methods

makeREOptions :: REOptions -> REOptions_ RE CompOption ExecOption

IsOption (Macros RE) RE CompOption ExecOption

Methods

makeREOptions :: Macros RE -> REOptions_ RE CompOption ExecOption

reSource :: RE -> String

extract the RE source string from the RE

Options

data SimpleREOptions

the default API uses these simple, universal RE options, which get auto-converted into the apropriate back-end REOptions_

Constructors

MultilineSensitive

case-sensitive with ^ and $ matching the start and end of a line

MultilineInsensitive

case-insensitive with ^ and $ matsh the start and end of a line

BlockSensitive

case-sensitive with ^ and $ matching the start and end of the input text

BlockInsensitive

case-insensitive with ^ and $ matching the start and end of the input text

Instances

Bounded SimpleREOptions

Methods

minBound :: SimpleREOptions

maxBound :: SimpleREOptions

Enum SimpleREOptions

Methods

succ :: SimpleREOptions -> SimpleREOptions

pred :: SimpleREOptions -> SimpleREOptions

toEnum :: Int -> SimpleREOptions

fromEnum :: SimpleREOptions -> Int

enumFrom :: SimpleREOptions -> [SimpleREOptions]

enumFromThen :: SimpleREOptions -> SimpleREOptions -> [SimpleREOptions]

enumFromTo :: SimpleREOptions -> SimpleREOptions -> [SimpleREOptions]

enumFromThenTo :: SimpleREOptions -> SimpleREOptions -> SimpleREOptions -> [SimpleREOptions]

Eq SimpleREOptions

Methods

(==) :: SimpleREOptions -> SimpleREOptions -> Bool

(/=) :: SimpleREOptions -> SimpleREOptions -> Bool

Ord SimpleREOptions

Methods

compare :: SimpleREOptions -> SimpleREOptions -> Ordering

(<) :: SimpleREOptions -> SimpleREOptions -> Bool

(<=) :: SimpleREOptions -> SimpleREOptions -> Bool

(>) :: SimpleREOptions -> SimpleREOptions -> Bool

(>=) :: SimpleREOptions -> SimpleREOptions -> Bool

max :: SimpleREOptions -> SimpleREOptions -> SimpleREOptions

min :: SimpleREOptions -> SimpleREOptions -> SimpleREOptions

Show SimpleREOptions

Methods

showsPrec :: Int -> SimpleREOptions -> ShowS

show :: SimpleREOptions -> String

showList :: [SimpleREOptions] -> ShowS

Lift SimpleREOptions

we need to use this in the quasi quoters to specify SimpleREOptions selected by the quasi quoter

Methods

lift :: SimpleREOptions -> Q Exp

Compiling and Escaping REs

data SearchReplace re s

contains a compiled RE and replacement template

Constructors

SearchReplace

Fields

• getSearch :: !re

  the RE

• getTemplate :: !s

  the replacement template

Instances

Functor (SearchReplace re)

Methods

fmap :: (a -> b) -> SearchReplace re a -> SearchReplace re b

(<$) :: a -> SearchReplace re b -> SearchReplace re a

(Show s, Show re) => Show (SearchReplace re s)

Methods

showsPrec :: Int -> SearchReplace re s -> ShowS

show :: SearchReplace re s -> String

showList :: [SearchReplace re s] -> ShowS

compileRegex :: (Functor m, Monad m) => String -> m RE

compile a String into a RE with the default options, generating an error if the RE is not well formed

compileRegexWith :: (Functor m, Monad m) => SimpleREOptions -> String -> m RE

compile a String into a RE using the given SimpleREOptions, generating an error if the RE is not well formed

compileSearchReplace :: (Monad m, Functor m, IsRegex RE s) => String -> String -> m (SearchReplace RE s)

compile a SearchReplace template generating errors if the RE or the template are not well formed, all capture references being checked

compileSearchReplaceWith :: (Monad m, Functor m, IsRegex RE s) => SimpleREOptions -> String -> String -> m (SearchReplace RE s)

compile a SearchReplace template, with simple options, generating errors if the RE or the template are not well formed, all capture references being checked

escape :: (Functor m, Monad m) => (String -> String) -> String -> m RE

convert a string into a RE that matches that string, and apply it to an argument continuation function to make up the RE string to be compiled; e.g., to compile a RE that will only match the string:

maybe undefined id . escape (("^"++) . (++"$"))

escapeWith :: (Functor m, Monad m) => SimpleREOptions -> (String -> String) -> String -> m RE

a variant of escape where the SimpleREOptions are specified

escapeREString :: String -> String

Convert a string into a regular expression that will match that string

The Classic rexex-base Match Operators

(=~) :: (RegexContext Regex s a, RegexMaker Regex CompOption ExecOption s) => s -> RE -> a

the regex-base polymorphic match operator

(=~~) :: (Monad m, RegexContext Regex s a, RegexMaker Regex CompOption ExecOption s) => s -> RE -> m a

the regex-base monadic, polymorphic match operator

IsRegex

class Replace s => IsRegex re s where

the IsRegex class allows polymorhic tools to be written that will work with a variety of regex back ends and text types

Minimal complete definition

matchOnce, matchMany, makeRegexWith, makeSearchReplaceWith, regexSource

Methods

matchOnce :: re -> s -> Match s

finding the first match

matchMany :: re -> s -> Matches s

finding all matches

makeRegex :: (Functor m, Monad m) => s -> m re

compiling an RE, failing if the RE is not well formed

makeRegexWith :: (Functor m, Monad m) => SimpleREOptions -> s -> m re

comiling an RE, specifying the SimpleREOptions

makeSearchReplace :: (Functor m, Monad m, IsRegex re s) => s -> s -> m (SearchReplace re s)

compiling a SearchReplace template from the RE text and the template Text, failing if they are not well formed

makeSearchReplaceWith :: (Functor m, Monad m, IsRegex re s) => SimpleREOptions -> s -> s -> m (SearchReplace re s)

compiling a SearchReplace template specifing the SimpleREOptions for the RE

makeEscaped :: (Functor m, Monad m) => (s -> s) -> s -> m re

incorporate an escaped string into a compiled RE with the default options

makeEscapedWith :: (Functor m, Monad m) => SimpleREOptions -> (s -> s) -> s -> m re

incorporate an escaped string into a compiled RE with the specified SimpleREOptions

regexSource :: re -> s

extract the text of the RE from the RE

The Quasi Quoters and Minor Functions

The [re|.*|] quasi quoters, with variants for specifing different options to the RE compiler (see Text.RE.REOptions), and the specialised back-end types and functions.

module Text.RE.ZeInternals.TDFA

The [ed|.*///foo|] quasi quoters, with variants for specifing different options to the RE compiler (see Text.RE.REOptions).

module Text.RE.ZeInternals.SearchReplace.TDFA

The Operator Instances

These modules merely provide the IsRegex instances.

module Text.RE.TDFA.ByteString

module Text.RE.TDFA.ByteString.Lazy

module Text.RE.TDFA.Sequence

module Text.RE.TDFA.String

module Text.RE.TDFA.Text

module Text.RE.TDFA.Text.Lazy