Copyright	(c) Chris Kuklewicz 2007
License	BSD-style (see the file LICENSE)
Maintainer	libraries@haskell.org, textregexlazy@personal.mightyreason.com
Stability	experimental
Portability	non-portable (regex-base needs MPTC+FD)
Safe Haskell	None
Language	Haskell98

Text.Regex.Posix.ByteString.Lazy

Contents

Types
Miscellaneous
Medium level API functions
Compilation options
Execution options

Description

This provides Lazy instances for RegexMaker and RegexLike based on Text.Regex.Posix.Wrap, and a (RegexContext Regex ByteString ByteString) instance.

To use these instance, you would normally import Text.Regex.Posix. You only need to import this module to use the medium level API of the compile, regexec, and execute functions. All of these report error by returning Left values instead of undefined or error or fail.

A Lazy ByteString with more than one chunk cannot be be passed to the library efficiently (as a pointer). It will have to converted via a full copy to a temporary normal bytestring (with a null byte appended if necessary).

Synopsis

Types

data Regex

A compiled regular expression.

Instances

RegexOptions Regex CompOption ExecOption

type MatchOffset = Int

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

type MatchLength = Int

non-negative length of a match

data ReturnCode

ReturnCode is an enumerated CInt, corresponding to the error codes from man 3 regex:

retBadbr (REG_BADBR) invalid repetition count(s) in { }
retBadpat (REG_BADPAT) invalid regular expression
retBadrpt (REG_BADRPT) ?, *, or + operand invalid
retEcollate (REG_ECOLLATE) invalid collating element
retEctype (REG_ECTYPE) invalid character class
retEescape (REG_EESCAPE) \ applied to unescapable character
retEsubreg (REG_ESUBREG) invalid backreference number
retEbrack (REG_EBRACK) brackets [ ] not balanced
retEparen (REG_EPAREN) parentheses ( ) not balanced
retEbrace (REG_EBRACE) braces { } not balanced
retErange (REG_ERANGE) invalid character range in [ ]
retEspace (REG_ESPACE) ran out of memory
retNoMatch (REG_NOMATCH) The regexec() function failed to match

Instances

Eq ReturnCode
Show ReturnCode

type WrapError = (ReturnCode, String)

The return code will be retOk when it is the Haskell wrapper and not the underlying library generating the error message.

Miscellaneous

unusedOffset :: Int

Medium level API functions

compile

Arguments

:: CompOption	Flags (summed together)
-> ExecOption	Flags (summed together)
-> ByteString	The regular expression to compile
-> IO (Either WrapError Regex)	Returns: the compiled regular expression

Compiles a regular expression

execute

Arguments

:: Regex	Compiled regular expression
-> ByteString	String to match against
-> IO (Either WrapError (Maybe (Array Int (MatchOffset, MatchLength))))	Returns: `Nothing` if the regex did not match the string, or: `Just` an array of (offset,length) pairs where index 0 is whole match, and the rest are the captured subexpressions.

Matches a regular expression against a buffer, returning the buffer indicies of the match, and any submatches

| Matches a regular expression against a string

regexec

Arguments

:: Regex	Compiled regular expression
-> ByteString	String to match against
-> IO (Either WrapError (Maybe (ByteString, ByteString, ByteString, [ByteString])))

Compilation options

newtype CompOption

A bitmapped CInt containing options for compilation of regular expressions. Option values (and their man 3 regcomp names) are

compBlank which is a completely zero value for all the flags. This is also the blankCompOpt value.
compExtended (REG_EXTENDED) which can be set to use extended instead of basic regular expressions. This is set in the defaultCompOpt value.
compNewline (REG_NEWLINE) turns on newline sensitivity: The dot (.) and inverted set [^ ] never match newline, and ^ and $ anchors do match after and before newlines. This is set in the defaultCompOpt value.
compIgnoreCase (REG_ICASE) which can be set to match ignoring upper and lower distinctions.
compNoSub (REG_NOSUB) which turns off all information from matching except whether a match exists.

Constructors

CompOption CInt

Instances

Eq CompOption
Num CompOption
Show CompOption
Bits CompOption
RegexOptions Regex CompOption ExecOption

compBlank :: CompOption

A completely zero value for all the flags. This is also the blankCompOpt value.

compExtended :: CompOption

compIgnoreCase :: CompOption

compNoSub :: CompOption

compNewline :: CompOption

Execution options

newtype ExecOption

A bitmapped CInt containing options for execution of compiled regular expressions. Option values (and their man 3 regexec names) are

execBlank which is a complete zero value for all the flags. This is the blankExecOpt value.
execNotBOL (REG_NOTBOL) can be set to prevent ^ from matching at the start of the input.
execNotEOL (REG_NOTEOL) can be set to prevent $ from matching at the end of the input (before the terminating NUL).

Constructors

ExecOption CInt

Instances

Eq ExecOption
Num ExecOption
Show ExecOption
Bits ExecOption
RegexOptions Regex CompOption ExecOption

execBlank :: ExecOption

A completely zero value for all the flags. This is also the blankExecOpt value.

execNotBOL :: ExecOption

execNotEOL :: ExecOption