Portability	non-portable (MPTC+FD)
Stability	experimental
Maintainer	libraries@haskell.org, textregexlazy@personal.mightyreason.com

Text.Regex.Base.RegexLike

Contents

Type aliases
Data types
Classes

Description

Classes and instances for Regex matching.

All the classes are declared here, and some common type aliases, and the MatchResult data type.

The only instances here are for Extract String and Extract ByteString. There are no data values. The RegexContext instances are in Text.Regex.Base.Context, except for ones which run afoul of a repeated variable (RegexContext regex a a), which are defined in each modules' String and ByteString modules.

Synopsis

Type aliases

type MatchOffset = Int Source

0 based index from start of source, or (-1) for unused

type MatchLength = Int Source

non-negative length of a match

type MatchArray = Array Int (MatchOffset, MatchLength)Source

0 based array, with 0th index indicating the full match. If the full match location is not available, represent as (0,0).

type MatchText source = Array Int (source, (MatchOffset, MatchLength))Source

Data types

data MatchResult a Source

This is the same as the type from JRegex.

Constructors

MR
Fields mrBefore :: a mrMatch :: a mrAfter :: a mrSubList :: [a] mrSubs :: Array Int a

Instances

RegexLike a b => RegexContext a b (MatchResult b)

Classes

class RegexOptions regex compOpt execOpt | regex -> compOpt execOpt, compOpt -> regex execOpt, execOpt -> regex compOpt whereSource

Rather than carry them around spearately, the options for how to execute a regex are kept as part of the regex. There are two types of options. Those that can only be specified at compilation time and never changed are CompOpt. Those that can be changed later and affect how matching is performed are ExecOpt. The actually types for these depend on the backend.

Methods

blankCompOpt Source

Arguments

:: compOpt

no options set at all in the backend

blankExecOpt Source

Arguments

:: execOpt

no options set at all in the backend

defaultCompOpt Source

Arguments

:: compOpt

reasonable options (extended,caseSensitive,multiline regex)

defaultExecOpt Source

Arguments

:: execOpt

reasonable options (extended,caseSensitive,multiline regex)

setExecOpts :: execOpt -> regex -> regexSource

forget old flags and use new ones

getExecOpts :: regex -> execOptSource

retrieve the current flags

class RegexOptions regex compOpt execOpt => RegexMaker regex compOpt execOpt source | regex -> compOpt execOpt, compOpt -> regex execOpt, execOpt -> regex compOpt whereSource

RegexMaker captures the creation of the compiled regular expression from a source type and an option type. The makeRegex function has a default implementation that depends on makeRegexOpts and used defaultCompOpt and defaultExecOpt.

Methods

makeRegex :: source -> regexSource

make using the defaultCompOpt and defaultExecOpt

makeRegexOpts :: compOpt -> execOpt -> source -> regexSource

Specify your own options

class Extract source => RegexLike regex source whereSource

RegexLike is parametrized on a regular expression type and a source type to run the matching on.

There are default implementations: matchTest and matchOnceText using matchOnce; matchCount and matchAllText using matchAll. matchOnce uses matchOnceText and matchAll uses matchAllText. So a minimal complete instance need to provide (matchOnce or matchOnceText) and (matchAll or matchAllText).

Methods

matchAll :: regex -> source -> [MatchArray]Source

matchOnce :: regex -> source -> Maybe MatchArray Source

This can return an array of (offset,length) index pairs for the match and captured substrings.

matchCount :: regex -> source -> Int Source

matchTest :: regex -> source -> Bool Source

matchAllText :: regex -> source -> [MatchText source]Source

matchOnceText :: regex -> source -> Maybe (source, MatchText source, source)Source

This can return a tuple of three items: the source before the match, an array of the match and captured substrings (with their indices), and the source after the match.

class RegexLike regex source => RegexContext regex source target whereSource

RegexContext is the polymorphic interface to do matching

Methods

match :: regex -> source -> targetSource

matchM :: Monad m => regex -> source -> m targetSource

Instances

RegexLike a b => RegexContext a b MatchArray
RegexLike a b => RegexContext a b Int
RegexLike a b => RegexContext a b ()
RegexLike a b => RegexContext a b Bool
RegexLike a b => RegexContext a b [[b]]
RegexLike a b => RegexContext a b [Array Int b]
RegexLike a b => RegexContext a b [b]
RegexLike a b => RegexContext a b [(MatchOffset, MatchLength)]
RegexLike a b => RegexContext a b [MatchText b]
RegexLike a b => RegexContext a b [MatchArray]
RegexLike a b => RegexContext a b (MatchResult b)
RegexLike a b => RegexContext a b (Array Int b)
RegexLike a b => RegexContext a b (MatchOffset, MatchLength)
RegexLike a b => RegexContext a b (b, b, b)
RegexLike a b => RegexContext a b (b, MatchText b, b)
RegexLike a b => RegexContext a b (b, b, b, [b])

class Extract source whereSource

Extract allows for indexing operations on String or ByteString.

Methods

before :: Int -> source -> sourceSource

before is a renamed take

after :: Int -> source -> sourceSource

after is a renamed drop

empty :: sourceSource

For when there is no match, this can construct an empty data value

extract :: (Int, Int) -> source -> sourceSource

extract takes an offset and length and has a default implementation of extract (off,len) source = before len (after off source)

Instances

Extract String
Extract ByteString