[12:7] extends: object
A GMatchInfo is an opaque struct used to return information about matches.
GMatchInfo (Handle = null)
Creates a new
MatchInfoby wrapping a native handle or another wrapper.
Handle is the native handle or another wrapper whose handle to adopt.toNativeHandle (Source)
Normalizes a constructor argument into a raw pointer carrier. Accepts a raw NativeHandle, a raw NativeBuffer returned from
fn.call(...), another generated wrapper exposinghandle(), or null. Returns null when the argument carries no pointer.
Source is the raw handle, raw buffer, wrapper, or null.A raw pointer carrier or null when no pointer is present.getLib ()
Returns the opened native library for this generated wrapper.
The opened native library.handle ()
Returns the wrapped NativeHandle.
The wrapped NativeHandle.isNull ()
Returns true when the wrapped handle is null.
A bool.describe ()
Returns a small string for debugging generated wrappers.
A string.expand_references (string string_to_expand)
Returns a new string containing the text in @string_to_expand with references and escape sequences expanded. References refer to the last match done with @string against @regex and have the same syntax used by g_regex_replace(). The @string_to_expand must be UTF-8 encoded even if %G_REGEX_RAW was passed to g_regex_new(). The backreferences are extracted from the string passed to the match function, so you cannot call this function after freeing the string. @match_info may be %NULL in which case @string_to_expand 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 g_regex_check_replacement() to find out whether @string_to_expand contains references.
string_to_expand is the string to expand.the expanded string, or %NULL if an error occurred.fetch (int match_num)
Retrieves the text matching the @match_num'th capturing parentheses. 0 is the full text of the match, 1 is the first paren set, 2 the second, and so on. If @match_num 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 g_regex_match_all() or g_regex_match_all_full(), 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.
match_num is number of the sub expression.The matched substring, or %NULL if an error occurred. You have to free the string yourself.fetch_all ()
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 g_regex_match_all() or g_regex_match_all_full(), 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.
a %NULL-terminated array of gchar * pointers. It must be freed using g_strfreev(). If the previous match failed %NULL is returned.fetch_named (string name)
Retrieves the text matching the capturing parentheses named @name. If
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.name is name of the subexpression.The matched substring, or %NULL if an error occurred. You have to free the string yourself.fetch_named_pos (string name)
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 @start_pos and @end_pos are set to -1 and %TRUE is returned. As @end_pos is set to the byte after the final byte of the match (on success), the length of the match can be calculated asend_pos - start_pos.
name is name of the subexpression.start_pos is pointer to location where to store the start position, or %NULL.end_pos is pointer to location where to store the end position (the byte after the final byte of the match), or %NULL.%TRUE if the position was fetched, %FALSE otherwise. If the position cannot be fetched, @start_pos and @end_pos are left unchanged..fetch_pos (int match_num)
Returns the start and end positions (in bytes) of a successfully matching capture parenthesis. Valid values for @match_num are
0for the full text of the match,1for the first paren set,2for the second, and so on. As @end_pos is set to the byte after the final byte of the match (on success), the length of the match can be calculated asend_pos - start_pos. As a best practice, initialize @start_pos and @end_pos to identifiable values, such asG_MAXINT, so that you can test ifg_match_info_fetch_pos()actually changed the value for a given capture parenthesis. The parameter @match_num corresponds to a matched capture parenthesis. The actual value you use for @match_num depends on the method used to generate @match_info. The following sections describe those methods. ## Methods Using Non-deterministic Finite Automata Matching The methods [method@GLib.Regex.match] and [method@GLib.Regex.match_full] return a [struct@GLib.MatchInfo] using traditional (greedy) pattern matching, also known as Non-deterministic Finite Automaton (NFA) matching. You pass the returnedGMatchInfofrom these methods tog_match_info_fetch_pos()to determine the start and end positions of capture parentheses. The values for @match_num correspond to the capture parentheses in order, with0corresponding to the entire matched string. @match_num can refer to a capture parenthesis with no match. For example, the stringbmatches against the pattern(a)?b, but the capture parenthesis(a)has no match. In this case,g_match_info_fetch_pos()returns true and sets @start_pos and @end_pos to-1when called withmatch_numas1(for(a)). For an expanded example, a regex pattern is(a)?(.*?)the (.*), and a candidate string isglib regexes are the best. In this scenario there are four capture parentheses numbered 0–3: an implicit one for the entire string, and three explicitly declared in the regex pattern. Given this example, the following table describes the return values fromg_match_info_fetch_pos()for various values of @match_num.match_num| Contents | Return value | Returnedstart_pos| Returnedend_pos----------- | -------- | ------------ | -------------------- | ------------------ 0 | Matches entire string | True | 0 | 25 1 | Does not match first character | True | -1 | -1 2 | All text beforethe| True | 0 | 17 3 | All text afterthe| True | 21 | 25 4 | Capture paren out of range | False | Unchanged | Unchanged The following code sample and output implements this example.{ .c } #include <glib.h> int main (int argc, char *argv[]) { g_autoptr(GError) local_error = NULL; const char *regex_pattern = "(a)?(.*?)the (.*)"; const char *test_string = "glib regexes are the best"; g_autoptr(GRegex) regex = NULL; regex = g_regex_new (regex_pattern, G_REGEX_DEFAULT, G_REGEX_MATCH_DEFAULT, &local_error); if (regex == NULL) { g_printerr ("Error creating regex: %s\n", local_error->message); return 1; } g_autoptr(GMatchInfo) match_info = NULL; g_regex_match (regex, test_string, G_REGEX_MATCH_DEFAULT, &match_info); int n_matched_strings = g_match_info_get_match_count (match_info); // Print header line g_print ("match_num Contents Return value returned start_pos returned end_pos\n"); // Iterate over each capture paren, including one that is out of range as a demonstration. for (int match_num = 0; match_num <= n_matched_strings; match_num++) { gboolean found_match; g_autofree char *paren_string = NULL; int start_pos = G_MAXINT; int end_pos = G_MAXINT; found_match = g_match_info_fetch_pos (match_info, match_num, &start_pos, &end_pos); // If no match, display N/A as the found string. if (start_pos == G_MAXINT || start_pos == -1) paren_string = g_strdup ("N/A"); else paren_string = g_strndup (test_string + start_pos, end_pos - start_pos); g_print ("%-9d %-25s %-12d %-18d %d\n", match_num, paren_string, found_match, start_pos, end_pos); } return 0; }match_num Contents Return value returned start_pos returned end_pos 0 glib regexes are the best 1 0 25 1 N/A 1 -1 -1 2 glib regexes are 1 0 17 3 best 1 21 25 4 N/A 0 2147483647 2147483647## Methods Using Deterministic Finite Automata Matching The methods [method@GLib.Regex.match_all] and [method@GLib.Regex.match_all_full] return aGMatchInfousing Deterministic Finite Automaton (DFA) pattern matching. This algorithm detects overlapping matches. You pass the returnedGMatchInfofrom these methods tog_match_info_fetch_pos()to determine the start and end positions of each overlapping match. Use the method [method@GLib.MatchInfo.get_match_count] to determine the number of overlapping matches. For example, a regex pattern is<.*>, and a candidate string is<a> <b> <c>. In this scenario there are three implicit capture parentheses: one for the entire string, one for<a> <b>, and one for<a>. Given this example, the following table describes the return values fromg_match_info_fetch_pos()for various values of @match_num.match_num| Contents | Return value | Returnedstart_pos| Returnedend_pos----------- | -------- | ------------ | -------------------- | ------------------ 0 | Matches entire string | True | 0 | 11 1 | Matches<a> <b>| True | 0 | 7 2 | Matches<a>| True | 0 | 3 3 | Capture paren out of range | False | Unchanged | Unchanged The following code sample and output implements this example.{ .c } #include <glib.h> int main (int argc, char *argv[]) { g_autoptr(GError) local_error = NULL; const char *regex_pattern = "<.*>"; const char *test_string = "<a> <b> <c>"; g_autoptr(GRegex) regex = NULL; regex = g_regex_new (regex_pattern, G_REGEX_DEFAULT, G_REGEX_MATCH_DEFAULT, &local_error); if (regex == NULL) { g_printerr ("Error creating regex: %s\n", local_error->message); return -1; } g_autoptr(GMatchInfo) match_info = NULL; g_regex_match_all (regex, test_string, G_REGEX_MATCH_DEFAULT, &match_info); int n_matched_strings = g_match_info_get_match_count (match_info); // Print header line g_print ("match_num Contents Return value returned start_pos returned end_pos\n"); // Iterate over each capture paren, including one that is out of range as a demonstration. for (int match_num = 0; match_num <= n_matched_strings; match_num++) { gboolean found_match; g_autofree char *paren_string = NULL; int start_pos = G_MAXINT; int end_pos = G_MAXINT; found_match = g_match_info_fetch_pos (match_info, match_num, &start_pos, &end_pos); // If no match, display N/A as the found string. if (start_pos == G_MAXINT || start_pos == -1) paren_string = g_strdup ("N/A"); else paren_string = g_strndup (test_string + start_pos, end_pos - start_pos); g_print ("%-9d %-25s %-12d %-18d %d\n", match_num, paren_string, found_match, start_pos, end_pos); } return 0; }match_num Contents Return value returned start_pos returned end_pos 0 <a> <b> <c> 1 0 11 1 <a> <b> 1 0 7 2 <a> 1 0 3 3 N/A 0 2147483647 2147483647
match_num is number of the capture parenthesis.start_pos is pointer to location where to store the start position, or %NULL.end_pos is pointer to location where to store the end position (the byte after the final byte of the match), or %NULL.True if @match_num is within range, false otherwise. If the capture paren has a match, @start_pos and @end_pos contain the start and end positions (in bytes) of the matching substring. If the capture paren has no match, @start_pos and @end_pos are -1. If @match_num is out of range, @start_pos and @end_pos are left unchanged..free ()
If @match_info is not %NULL, calls g_match_info_unref(); otherwise does nothing.
None.get_match_count ()
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 g_regex_match_all() or g_regex_match_all_full(), the retrieved count is not that of the number of capturing parentheses but that of the number of matched substrings.
Number of matched substrings, or -1 if an error occurred.get_regex ()
Returns #GRegex object used in @match_info. It belongs to Glib and must not be freed. Use g_regex_ref() if you need to keep it after you free
object.#GRegex object used in @match_info.get_string ()
Returns the string searched with @match_info. This is the string passed to g_regex_match() or g_regex_replace() so you may not free it before calling this function.
the string searched with @match_info.is_partial_match ()
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 g_regex_match() or g_regex_match_full() 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 g_match_info_is_partial_match(). 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.
%TRUE if the match was partial, %FALSE otherwise.matches ()
Returns whether the previous match operation succeeded.
%TRUE if the previous match operation succeeded, %FALSE otherwise.next ()
Scans for the next match using the same parameters of the previous call to g_regex_match_full() or g_regex_match() that returned @match_info. The match is done on the string passed to the match function, so you cannot free it before calling this function.
%TRUE is the string matched, %FALSE otherwise.ref ()
Increases reference count of @match_info by 1.
@match_info.unref ()
Decreases reference count of @match_info by 1. When reference count drops to zero, it frees all the memory associated with the match_info structure.
None.
