regex-posix-0.95.2: Replaces/Enhances Text.Regex

Copyright (c) Chris Kuklewicz 200620072008 derived from (c) The University of Glasgow 2002 BSD-style (see the file LICENSE) libraries@haskell.org, textregexlazy@personal.mightyreason.com experimental non-portable (regex-base needs MPTC+FD) None Haskell98

Text.Regex.Posix.Wrap

Description

WrapPosix.hsc exports a wrapped version of the ffi imports. To increase type safety, the flags are newtype'd. The other important export is a Regex type that is specific to the Posix library backend. The flags are documented in Text.Regex.Posix. The defaultCompOpt is (compExtended .|. compNewline).

The Regex, CompOption, and ExecOption types and their RegexOptions instance is declared. The =~ and =~~ convenience functions are defined.

The exported symbols are the same whether HAVE_REGEX_H is defined, but when it is not defined then getVersion == Nothing and all other exported values will call error or fail.

This module will fail or error only if allocation fails or a nullPtr is passed in.

2009-January : wrapMatchAll and wrapCount now adjust the execution option execNotBOL after the first result to take into account '\n' in the text immediately before the next matches. (version 0.93.3)

2009-January : wrapMatchAll and wrapCount have been changed to return all non-overlapping matches, including empty matches even if they coincide with the end of the previous non-empty match. The change is that the first non-empty match no longer terminates the search. One can filter the results to obtain the old behavior or to obtain the behavior of "sed", where "sed" eliminates the empty matches which coincide with the end of non-empty matches. (version 0.94.0)

Synopsis

## High-level API

data Regex #

A compiled regular expression.

Instances

 # Methods

type RegOffset = Int64 #

RegOffset is "typedef int regoff_t" on Linux and ultimately "typedef long long __int64_t" on Max OS X. So rather than saying 2,147,483,647 is all the length you need, I'll take the larger: 9,223,372,036,854,775,807 should be enough bytes for anyone, no need for Integer. The alternative is to compile to different sizes in a platform dependent manner with "type RegOffset = (#type regoff_t)", which I do not want to do.

There is also a special value unusedRegOffset :: RegOffset which is (-1) and as a starting index means that the subgroup capture was unused. Otherwise the RegOffset indicates a character boundary that is before the character at that index offset, with the first character at index offset 0. So starting at 1 and ending at 2 means to take only the second character.

(=~) :: (RegexMaker Regex CompOption ExecOption source, RegexContext Regex source1 target) => source1 -> source -> target #

(=~~) :: (RegexMaker Regex CompOption ExecOption source, RegexContext Regex source1 target, Monad m) => source1 -> source -> m target #

## Low-level API

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.

Arguments

 :: CompOption Flags (bitmapped) -> ExecOption Flags (bitmapped) -> CString The regular expression to compile (ASCII only, no null bytes) -> IO (Either WrapError Regex) Returns: the compiled regular expression

wrapMatch returns offsets for the begin and end of each capture. Unused captures have offsets of unusedRegOffset which is (-1)

wrapMatchAll returns the offset and length of each capture. Unused captures have an offset of unusedRegOffset which is (-1) and length of 0.

## 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 $anchors do match after and before newlines. This is set in the defaultCompOpt value. • compIgnoreCase (REG_ICASE) which can be set to match ignoring upper and lower distinctions. • compNoSub (REG_NOSUB) which turns off all information from matching except whether a match exists. Constructors  CompOption CInt Instances  # Methods # Methods # MethodsshowList :: [CompOption] -> ShowS # # Methods # Methods A completely zero value for all the flags. This is also the blankCompOpt value. ## Execution options newtype ExecOption # A bitmapped CInt containing options for execution of compiled regular expressions. Option values (and their man 3 regexec names) are • execBlank which is a complete zero value for all the flags. This is the blankExecOpt value. • execNotBOL (REG_NOTBOL) can be set to prevent ^ from matching at the start of the input. • execNotEOL (REG_NOTEOL) can be set to prevent$ from matching at the end of the input (before the terminating NUL).

Constructors

 ExecOption CInt

Instances

 # Methods # Methods # MethodsshowList :: [ExecOption] -> ShowS # # Methods # Methods

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

## Return codes

newtype ReturnCode #

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

• 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

Constructors

 ReturnCode CInt

Instances

 # Methods # MethodsshowList :: [ReturnCode] -> ShowS #