Text.Regex.Posix.Wrap

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

Copyright | (c) Chris Kuklewicz 2006,2007,2008 derived from (c) The University of Glasgow 2002
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.Wrap

Contents

- High-level API
- Low-level API
- Miscellaneous
- Compilation options
- Execution options
- Return codes

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

- data Regex
- type RegOffset = Int64
- type RegOffsetT = Int64
- (=~) :: (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
- type WrapError = (ReturnCode, String)
- wrapCompile :: CompOption -> ExecOption -> CString -> IO (Either WrapError Regex)
- wrapTest :: Regex -> CString -> IO (Either WrapError Bool)
- wrapMatch :: Regex -> CString -> IO (Either WrapError (Maybe [(RegOffset, RegOffset)]))
- wrapMatchAll :: Regex -> CString -> IO (Either WrapError [MatchArray])
- wrapCount :: Regex -> CString -> IO (Either WrapError Int)
- unusedRegOffset :: RegOffset
- newtype CompOption = CompOption CInt
- compBlank :: CompOption
- compExtended :: CompOption
- compIgnoreCase :: CompOption
- compNoSub :: CompOption
- compNewline :: CompOption
- newtype ExecOption = ExecOption CInt
- execBlank :: ExecOption
- execNotBOL :: ExecOption
- execNotEOL :: ExecOption
- newtype ReturnCode = ReturnCode CInt
- retBadbr :: ReturnCode
- retBadpat :: ReturnCode
- retBadrpt :: ReturnCode
- retEcollate :: ReturnCode
- retEctype :: ReturnCode
- retEescape :: ReturnCode
- retEsubreg :: ReturnCode
- retEbrack :: ReturnCode
- retEparen :: ReturnCode
- retEbrace :: ReturnCode
- retErange :: ReturnCode
- retEspace :: ReturnCode

## High-level API

data Regex

A compiled regular expression.

Instances

RegexOptions Regex CompOption ExecOption |

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.

type RegOffsetT = Int64

(=~) :: (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.

wrapCompile

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

wrapTest :: Regex -> CString -> IO (Either WrapError Bool)

wrapMatch :: Regex -> CString -> IO (Either WrapError (Maybe [(RegOffset, RegOffset)]))

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

wrapMatchAll :: Regex -> CString -> IO (Either WrapError [MatchArray])

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

wrapCount :: Regex -> CString -> IO (Either WrapError Int)

## Miscellaneous

unusedRegOffset :: RegOffset

## 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

## Return codes

newtype 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

Constructors

ReturnCode CInt |

Instances

Eq ReturnCode |
Show ReturnCode |

retBadbr :: ReturnCode

retBadpat :: ReturnCode

retBadrpt :: ReturnCode

retEcollate :: ReturnCode

retEctype :: ReturnCode

retEescape :: ReturnCode

retEsubreg :: ReturnCode

retEbrack :: ReturnCode

retEparen :: ReturnCode

retEbrace :: ReturnCode

retErange :: ReturnCode

retEspace :: ReturnCode