GI.GLib.Structs.MatchInfo

A GMatchInfo is an opaque struct used to return information about matches.

Exported types

newtype MatchInfo

Memory-managed wrapper type.

Constructors

MatchInfo (ManagedPtr MatchInfo)

Instances

Eq MatchInfo

Defined in GI.GLib.Structs.MatchInfo

Methods

(==) :: MatchInfo -> MatchInfo -> Bool

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

IsGValue MatchInfo

Convert MatchInfo to and from GValue with toGValue and fromGValue.

Defined in GI.GLib.Structs.MatchInfo

Methods

toGValue :: MatchInfo -> IO GValue

fromGValue :: GValue -> IO MatchInfo

BoxedObject MatchInfo

Defined in GI.GLib.Structs.MatchInfo

Methods

boxedType :: MatchInfo -> IO GType

noMatchInfo :: Maybe MatchInfo

A convenience alias for Nothing :: Maybe MatchInfo.

Methods

Overloaded methods

expandReferences

matchInfoExpandReferences

Arguments

:: (HasCallStack, MonadIO m)

=> MatchInfo

matchInfo: a MatchInfo or Nothing

-> Text

stringToExpand: the string to expand

-> m (Maybe Text)

Returns: the expanded string, or Nothing if an error occurred (Can throw GError)

Returns a new string containing the text in stringToExpand with references and escape sequences expanded. References refer to the last match done with string against regex and have the same syntax used by regexReplace.

The stringToExpand must be UTF-8 encoded even if G_REGEX_RAW was passed to regexNew.

The backreferences are extracted from the string passed to the match function, so you cannot call this function after freeing the string.

matchInfo may be Nothing in which case stringToExpand must not contain references. For instance "foo\n" does not refer to an actual pattern and '\n' merely will be replaced with \n character, while to expand "\0" (whole match) one needs the result of a match. Use regexCheckReplacement to find out whether stringToExpand contains references.

Since: 2.14

fetch

matchInfoFetch

Arguments

:: (HasCallStack, MonadIO m)

=> MatchInfo

matchInfo: MatchInfo structure

-> Int32

matchNum: number of the sub expression

-> m (Maybe Text)

Returns: The matched substring, or Nothing if an error occurred. You have to free the string yourself

Retrieves the text matching the matchNum'th capturing parentheses. 0 is the full text of the match, 1 is the first paren set, 2 the second, and so on.

If matchNum is a valid sub pattern but it didn't match anything (e.g. sub pattern 1, matching "b" against "(a)?b") then an empty string is returned.

If the match was obtained using the DFA algorithm, that is using regexMatchAll or regexMatchAllFull, the retrieved string is not that of a set of parentheses but that of a matched substring. Substrings are matched in reverse order of length, so 0 is the longest match.

The string is fetched from the string passed to the match function, so you cannot call this function after freeing the string.

Since: 2.14

fetchAll

matchInfoFetchAll

Arguments

:: (HasCallStack, MonadIO m)

=> MatchInfo

matchInfo: a MatchInfo structure

-> m [Text]

Returns: a Nothing-terminated array of gchar * pointers. It must be freed using strfreev. If the previous match failed Nothing is returned

Bundles up pointers to each of the matching substrings from a match and stores them in an array of gchar pointers. The first element in the returned array is the match number 0, i.e. the entire matched text.

If a sub pattern didn't match anything (e.g. sub pattern 1, matching "b" against "(a)?b") then an empty string is inserted.

If the last match was obtained using the DFA algorithm, that is using regexMatchAll or regexMatchAllFull, the retrieved strings are not that matched by sets of parentheses but that of the matched substring. Substrings are matched in reverse order of length, so the first one is the longest match.

The strings are fetched from the string passed to the match function, so you cannot call this function after freeing the string.

Since: 2.14

fetchNamed

matchInfoFetchNamed

Arguments

:: (HasCallStack, MonadIO m)

=> MatchInfo

matchInfo: MatchInfo structure

-> Text

name: name of the subexpression

-> m (Maybe Text)

Returns: The matched substring, or Nothing if an error occurred. You have to free the string yourself

Retrieves the text matching the capturing parentheses named name.

If name is a valid sub pattern name but it didn't match anything (e.g. sub pattern "X", matching "b" against "(?P<X>a)?b") then an empty string is returned.

The string is fetched from the string passed to the match function, so you cannot call this function after freeing the string.

Since: 2.14

fetchNamedPos

matchInfoFetchNamedPos

Arguments

:: (HasCallStack, MonadIO m)

=> MatchInfo

matchInfo: MatchInfo structure

-> Text

name: name of the subexpression

-> m (Bool, Int32, Int32)

Returns: True if the position was fetched, False otherwise. If the position cannot be fetched, startPos and endPos are left unchanged.

Retrieves the position in bytes of the capturing parentheses named name.

If name is a valid sub pattern name but it didn't match anything (e.g. sub pattern "X", matching "b" against "(?P<X>a)?b") then startPos and endPos are set to -1 and True is returned.

Since: 2.14

fetchPos

matchInfoFetchPos

Arguments

:: (HasCallStack, MonadIO m)

=> MatchInfo

matchInfo: MatchInfo structure

-> Int32

matchNum: number of the sub expression

-> m (Bool, Int32, Int32)

Returns: True if the position was fetched, False otherwise. If the position cannot be fetched, startPos and endPos are left unchanged

Retrieves the position in bytes of the matchNum'th capturing parentheses. 0 is the full text of the match, 1 is the first paren set, 2 the second, and so on.

If matchNum is a valid sub pattern but it didn't match anything (e.g. sub pattern 1, matching "b" against "(a)?b") then startPos and endPos are set to -1 and True is returned.

If the match was obtained using the DFA algorithm, that is using regexMatchAll or regexMatchAllFull, the retrieved position is not that of a set of parentheses but that of a matched substring. Substrings are matched in reverse order of length, so 0 is the longest match.

Since: 2.14

free

matchInfoFree

Arguments

:: (HasCallStack, MonadIO m)

=> MatchInfo

matchInfo: a MatchInfo, or Nothing

-> m ()

If matchInfo is not Nothing, calls matchInfoUnref; otherwise does nothing.

Since: 2.14

getMatchCount

matchInfoGetMatchCount

Arguments

:: (HasCallStack, MonadIO m)

=> MatchInfo

matchInfo: a MatchInfo structure

-> m Int32

Returns: Number of matched substrings, or -1 if an error occurred

Retrieves the number of matched substrings (including substring 0, that is the whole matched text), so 1 is returned if the pattern has no substrings in it and 0 is returned if the match failed.

If the last match was obtained using the DFA algorithm, that is using regexMatchAll or regexMatchAllFull, the retrieved count is not that of the number of capturing parentheses but that of the number of matched substrings.

Since: 2.14

getRegex

matchInfoGetRegex

Arguments

:: (HasCallStack, MonadIO m)

=> MatchInfo

matchInfo: a MatchInfo

-> m Regex

Returns: Regex object used in matchInfo

Returns Regex object used in matchInfo. It belongs to Glib and must not be freed. Use regexRef if you need to keep it after you free matchInfo object.

Since: 2.14

getString

matchInfoGetString

Arguments

:: (HasCallStack, MonadIO m)

=> MatchInfo

matchInfo: a MatchInfo

-> m Text

Returns: the string searched with matchInfo

Returns the string searched with matchInfo. This is the string passed to regexMatch or regexReplace so you may not free it before calling this function.

Since: 2.14

isPartialMatch

matchInfoIsPartialMatch

Arguments

:: (HasCallStack, MonadIO m)

=> MatchInfo

matchInfo: a MatchInfo structure

-> m Bool

Returns: True if the match was partial, False otherwise

Usually if the string passed to g_regex_match*() matches as far as it goes, but is too short to match the entire pattern, False is returned. There are circumstances where it might be helpful to distinguish this case from other cases in which there is no match.

Consider, for example, an application where a human is required to type in data for a field with specific formatting requirements. An example might be a date in the form ddmmmyy, defined by the pattern "^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$". If the application sees the user’s keystrokes one by one, and can check that what has been typed so far is potentially valid, it is able to raise an error as soon as a mistake is made.

GRegex supports the concept of partial matching by means of the G_REGEX_MATCH_PARTIAL_SOFT and G_REGEX_MATCH_PARTIAL_HARD flags. When they are used, the return code for regexMatch or regexMatchFull is, as usual, True for a complete match, False otherwise. But, when these functions return False, you can check if the match was partial calling matchInfoIsPartialMatch.

The difference between G_REGEX_MATCH_PARTIAL_SOFT and G_REGEX_MATCH_PARTIAL_HARD is that when a partial match is encountered with G_REGEX_MATCH_PARTIAL_SOFT, matching continues to search for a possible complete match, while with G_REGEX_MATCH_PARTIAL_HARD matching stops at the partial match. When both G_REGEX_MATCH_PARTIAL_SOFT and G_REGEX_MATCH_PARTIAL_HARD are set, the latter takes precedence.

There were formerly some restrictions on the pattern for partial matching. The restrictions no longer apply.

See pcrepartial(3) for more information on partial matching.

Since: 2.14

matches

matchInfoMatches

Arguments

:: (HasCallStack, MonadIO m)

=> MatchInfo

matchInfo: a MatchInfo structure

-> m Bool

Returns: True if the previous match operation succeeded, False otherwise

Returns whether the previous match operation succeeded.

Since: 2.14

next

matchInfoNext

Arguments

:: (HasCallStack, MonadIO m)

=> MatchInfo

matchInfo: a MatchInfo structure

-> m ()

(Can throw GError)

Scans for the next match using the same parameters of the previous call to regexMatchFull or regexMatch that returned matchInfo.

The match is done on the string passed to the match function, so you cannot free it before calling this function.

Since: 2.14

ref

matchInfoRef

Arguments

:: (HasCallStack, MonadIO m)

=> MatchInfo

matchInfo: a MatchInfo

-> m MatchInfo

Returns: matchInfo

Increases reference count of matchInfo by 1.

Since: 2.30

unref

matchInfoUnref

Arguments

:: (HasCallStack, MonadIO m)

=> MatchInfo

matchInfo: a MatchInfo

-> m ()

Decreases reference count of matchInfo by 1. When reference count drops to zero, it frees all the memory associated with the match_info structure.

Since: 2.30