Text.RE.Tools

The Tools Tutorial

This API module provides some familiar RE tools on top of the core package functions and types.

See the Regex Tools tutorial at http://re-tutorial-tools.regex.uk

Sed

sed :: IsRegex re ByteString => Edits IO re ByteString -> FilePath -> FilePath -> IO ()

read a file, apply an Edits script to each line it and write the file out again; "-" is used to indicate standard input standard output as appropriate

sed' :: (IsRegex re a, Monad m, Functor m) => Edits m re a -> a -> m a

apply an Edits script to each line of the argument text

Grep

grep :: IsRegex re ByteString => Verbosity -> re -> FilePath -> IO ()

operates a bit like classic grep printing out the lines matched

data Verbosity

specifies whether to return the linss matched or missed

Constructors

LinesMatched

LinesNotMatched

Instances

Eq Verbosity

Methods

(==) :: Verbosity -> Verbosity -> Bool

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

Ord Verbosity

Methods

compare :: Verbosity -> Verbosity -> Ordering

(<) :: Verbosity -> Verbosity -> Bool

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

(>) :: Verbosity -> Verbosity -> Bool

(>=) :: Verbosity -> Verbosity -> Bool

max :: Verbosity -> Verbosity -> Verbosity

min :: Verbosity -> Verbosity -> Verbosity

Show Verbosity

Methods

showsPrec :: Int -> Verbosity -> ShowS

show :: Verbosity -> String

showList :: [Verbosity] -> ShowS

data Line s

grepLines returns a Line for each line in the file, listing all of the Matches for that line

Constructors

Line

Fields

• getLineNumber :: LineNo

  the LineNo for this line

• getLineMatches :: Matches s

  all the Matches of the RE on this line

Instances

Show s => Show (Line s)

Methods

showsPrec :: Int -> Line s -> ShowS

show :: Line s -> String

showList :: [Line s] -> ShowS

grepLines :: IsRegex re ByteString => re -> FilePath -> IO [Line ByteString]

returns a Line for each line in the file, enumerating all of the matches for that line

grepFilter :: IsRegex re s => re -> s -> [Line s]

returns a Line for each line in the argument text, enumerating all of the matches for that line

type GrepScript re s t = [(re, LineNo -> Matches s -> Maybe t)]

a GrepScript lists RE-action associations, with the first RE to match a line selecting the action to be executed on each line in the file

grepWithScript :: IsRegex re s => GrepScript re s t -> [s] -> [t]

given a list of lines, apply the GrepScript to each line of the file

report :: Verbosity -> [Line ByteString] -> String

generate a grep report from a list of Line

linesMatched :: Verbosity -> [Line s] -> [Line s]

given a velocity flag filter out either the lines matched or not matched

Lex

alex :: IsRegex re s => [(re, Match s -> Maybe t)] -> t -> s -> [t]

a simple regex-based scanner interpretter for prototyping scanners

alex' :: Replace s => (re -> s -> Match s) -> [(re, Match s -> Maybe t)] -> t -> s -> [t]

a higher order version of alex parameterised over the matchOnce function

Find

data FindMethods s

as we don't want the directory and FilePath dependencies we will abstract the three calls we need into this record type

Constructors

FindMethods

Fields

• doesDirectoryExistDM :: s -> IO Bool

  doesDirectoryExist from System.Directory

• listDirectoryDM :: s -> IO [s]

  either getDirectoryContents or listDirectory from System.Directory

• combineDM :: s -> s -> s

  / from System.FilePath

findMatches_ :: IsRegex re s => FindMethods s -> re -> s -> IO [s]

recursively list all files whose filename matches given RE, sorting the list into ascending order; if the argument path has a trailing / then it will be removed

findMatches_'

Arguments

:: IsRegex re s

=> FindMethods s

the directory and filepath methods

-> ([s] -> [s])

result post-processing function

-> (Match s -> Bool)

filtering function

-> re

re to be matched against the leaf filename

-> s

root directory of the search

-> IO [s]

recursively list all files whose filename matches given RE, using the given function to determine which matches to accept

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

data SearchReplace re s

contains a compiled RE and replacement template

Constructors

SearchReplace

Fields

• getSearch :: !re

  the RE to match a string to replace

• getTemplate :: !s

  the replacement template with ${cap} used to identify a capture (by number or name if one was given) and $$ being used to escape a single $

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

searchReplaceAll :: IsRegex re s => SearchReplace re s -> s -> s

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

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

searchReplaceFirst :: IsRegex re s => SearchReplace re s -> s -> s

search and replace the first occurrence only (if any) in the input text e.g., to prefix the first string of four hex digits in the imput text, if any, with 0x:

searchReplaceFirst [ed|[0-9A-Fa-f]{4}///0x$0|]

Edit

data Edits m re s

an Edits script will, for each line in the file, either perform the action selected by the first RE in the list, or perform all of the actions on line, arranged as a pipeline

Constructors

Select ![Edit m re s]

for each line select the first Edit to match each line and edit the line with it

Pipe ![Edit m re s]

for each line apply every edit that matches in turn to the line

data Edit m re s

each Edit action specifies how the match should be processed

Constructors

Template !(SearchReplace re s)

replace the match with this template text, substituting ${capture} as apropriate

Function !re REContext !(LineNo -> Match s -> RELocation -> Capture s -> m (Maybe s))

use this function to replace the REContext specified captures in each line matched

LineEdit !re !(LineNo -> Matches s -> m (LineEdit s))

use this function to edit each line matched

data LineEdit s

a LineEdit is the most general action thar can be performed on a line and is the only means of deleting a line

Constructors

NoEdit

do not edit this line but leave as is

ReplaceWith !s

replace the line with this text (terminating newline should not be included)

Delete

delete the this line altogether

Instances

Functor LineEdit

Methods

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

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

Show s => Show (LineEdit s)

Methods

showsPrec :: Int -> LineEdit s -> ShowS

show :: LineEdit s -> String

showList :: [LineEdit s] -> ShowS

applyEdits :: (IsRegex re s, Monad m, Functor m) => LineNo -> Edits m re s -> s -> m s

apply an Edit script to a single line

applyEdit :: (IsRegex re s, Monad m, Functor m) => (s -> s) -> LineNo -> Edit m re s -> s -> m (Maybe s)

apply a single edit action to a line, the function in the first argument being used to add a new line onto the end of the line where appropriate; the function returns Nothing if no edit is to be performed on the line, Just mempty to delete the line

applyLineEdit :: Monoid s => (s -> s) -> LineEdit s -> Maybe s

apply a LineEdit to a line, using the function in the first argument to append a new line to the result; Nothing should be returned if no edit is to be performed, Just mempty to delete the line

LineNo

newtype LineNo

our line numbers are of the proper zero-based kind

Constructors

ZeroBasedLineNo

Fields

• getZeroBasedLineNo :: Int

Instances

Enum LineNo

Methods

succ :: LineNo -> LineNo

pred :: LineNo -> LineNo

toEnum :: Int -> LineNo

fromEnum :: LineNo -> Int

enumFrom :: LineNo -> [LineNo]

enumFromThen :: LineNo -> LineNo -> [LineNo]

enumFromTo :: LineNo -> LineNo -> [LineNo]

enumFromThenTo :: LineNo -> LineNo -> LineNo -> [LineNo]

Show LineNo

Methods

showsPrec :: Int -> LineNo -> ShowS

show :: LineNo -> String

showList :: [LineNo] -> ShowS

firstLine :: LineNo

the first line in a file

getLineNo :: LineNo -> Int

extract a conventional 1-based line number

lineNo :: Int -> LineNo

inject a conventional 1-based line number

Replace

module Text.RE.Replace