Safe Haskell	None
Language	Haskell2010

Hledger.Utils.Regex

Contents

type aliases
standard regex operations

Description

Easy regular expression helpers, currently based on regex-tdfa. These should:

be cross-platform, not requiring C libraries
support unicode
support extended regular expressions
support replacement, with backreferences etc.
support splitting
have mnemonic names
have simple monomorphic types
work with simple strings

Regex strings are automatically compiled into regular expressions the first time they are seen, and these are cached. If you use a huge number of unique regular expressions this might lead to increased memory usage. Several functions have memoised variants (*Memo), which also trade space for time.

Current limitations:

(?i) and similar are not supported

Synopsis

type Regexp = String
type Replacement = String
regexMatches :: Regexp -> String -> Bool
regexMatchesCI :: Regexp -> String -> Bool
regexReplace :: Regexp -> Replacement -> String -> String
regexReplaceCI :: Regexp -> Replacement -> String -> String
regexReplaceMemo :: Regexp -> Replacement -> String -> String
regexReplaceCIMemo :: Regexp -> Replacement -> String -> String
regexReplaceBy :: Regexp -> (String -> String) -> String -> String
regexReplaceByCI :: Regexp -> (String -> String) -> String -> String

type aliases

type Regexp = String Source #

Regular expression. Extended regular expression-ish syntax ? But does not support eg (?i) syntax.

type Replacement = String Source #

A replacement pattern. May include numeric backreferences (N).

standard regex operations

regexMatches :: Regexp -> String -> Bool Source #

regexMatchesCI :: Regexp -> String -> Bool Source #

regexReplace :: Regexp -> Replacement -> String -> String Source #

Replace all occurrences of the regexp with the replacement pattern. The replacement pattern supports numeric backreferences (N) but no other RE syntax.

regexReplaceCI :: Regexp -> Replacement -> String -> String Source #

regexReplaceMemo :: Regexp -> Replacement -> String -> String Source #

A memoising version of regexReplace. Caches the result for each search pattern, replacement pattern, target string tuple.

regexReplaceCIMemo :: Regexp -> Replacement -> String -> String Source #

regexReplaceBy :: Regexp -> (String -> String) -> String -> String Source #

Replace all occurrences of the regexp, transforming each match with the given function.

regexReplaceByCI :: Regexp -> (String -> String) -> String -> String Source #