Add GLib's regex library into Lua

While Lua's built-in pattern support is ok for simple things, many people end
up wanting a real regex engine. Since Wireshark already includes the GLib
Regex library (a wrapper for PCRE), it makes sense to expose that library to
Lua scripts. This has been done using Lrexlib, one of the most popular regex
bindings for Lua. Lrexlib didn't support binding GLib's Regex in particular -
it does for PCRE but GLib is a different API - so I've done that. A fairly
thorough testsuite came along with that, which has been incorporated into the
wireshark wslua testuites as well in this commit.

Change-Id: I05811d1edf7af8d7c9f4f081de6850f31c0717c7
Reviewed-on: https://code.wireshark.org/review/332
Reviewed-by: Anders Broman <a.broman58@gmail.com>

2 files changed, 487 insertions, 1 deletions

diff --git a/docbook/CMakeLists.txt b/docbook/CMakeLists.txt
index bbcf284b2d..0373da5f76 100644
--- a/docbook/CMakeLists.txt
+++ b/docbook/CMakeLists.txt
@@ -310,7 +310,6 @@ set(WSLUA_MODULES
 	${CMAKE_SOURCE_DIR}/epan/wslua/wslua_tree.c
 	${CMAKE_SOURCE_DIR}/epan/wslua/wslua_tvb.c
 	${CMAKE_SOURCE_DIR}/epan/wslua/wslua_util.c
-	${CMAKE_SOURCE_DIR}/epan/wslua/wslua_int64.c
 	${CMAKE_SOURCE_DIR}/epan/wslua/wslua_struct.c
 )
 
diff --git a/docbook/wsluarm.xml b/docbook/wsluarm.xml
index 261c65fe30..1a01b568d4 100644
--- a/docbook/wsluarm.xml
+++ b/docbook/wsluarm.xml
@@ -179,4 +179,491 @@ end
 	&WsLuaUtility;
 	&WsLuaInt64;
 	&WsLuaStruct;
+
+	<section id='lua_module_GRegex'>
+		<title> GLib Regular Expressions </title>
+		<para>
+		  Lua has its own native 'pattern' syntax in the string library, but sometimes a real
+		  regex engine is more useful.  Wireshark comes with GLib's Regex implementation, which
+		  itself is based on Perl Compatible Regular Expressions (PCRE). This engine is exposed
+		  into Wireshark's Lua engine through the well-known Lrexlib library, following the
+		  same syntax and semantics as the Lrexlib PCRE implementation, with a few differences as follows:
+		    <itemizedlist>
+			    <listitem>
+				    <para> There is no support for using custom locale/chartables </para>
+			    </listitem>
+			    <listitem>
+				    <para> dfa_exec() doesn't take 'ovecsize' nor 'wscount' arguments </para>
+			    </listitem>
+			    <listitem>
+				    <para> dfa_exec() returns boolean true for partial match, without subcapture info </para>
+			    </listitem>
+			    <listitem>
+				    <para> Named subgroups do not return name-keyed entries in the return
+						table (i.e., in match/tfind/exec)
+				    </para>
+			    </listitem>
+			    <listitem>
+				    <para> The 'flags()' function still works, returning all flags, but two new
+						functions 'compile_flags()' and 'match_flags()' return just their respective
+						flags, since GLib has a different and smaller set of such flags, for
+						regex compile vs. match functions
+					</para>
+			    </listitem>
+			    <listitem>
+					<para>
+						Using some assertions and POSIX character classes against strings with non-ASCII characters
+						might match high-order characters, because glib always sets PCRE_UCP
+						even if G_REGEX_RAW is set. For example, '[:alpha;]' matches certain
+						non-ASCII bytes.  The following assertions have this issue: '\b', '\B', '\s', '\S', '\w', '\W'.
+						The following character classes have this issue: [:alpha:], [:alnum:], [:lower:], [:upper:],
+						[:space:], [:word:], and [:graph:].
+					</para>
+			    </listitem>
+			    <listitem>
+					<para>
+						The compile flag G_REGEX_RAW is always set/used, even if you didn't specify it. This is because
+						GLib runs PCRE in UTF-8 mode by default, whereas Lua strings are not UTF-aware.
+					</para>
+			    </listitem>
+			</itemizedlist>
+		</para>
+		<para>
+		  This page is based on the full documentation for Lrexlib at
+		      <ulink url="http://rrthomas.github.io/lrexlib/manual.html">http://rrthomas.github.io/lrexlib/manual.html</ulink>
+		</para>
+		<para>
+			The GLib Regular expression syntax (which is essentially PCRE syntax) can be found at
+			<ulink url="https://developer.gnome.org/glib/2.38/glib-regex-syntax.html">https://developer.gnome.org/glib/2.38/glib-regex-syntax.html</ulink>
+		</para>
+		<section id='lua_class_GRegex'><title>GRegex</title>
+			<para>
+				GLib Regular Expressions based on PCRE.
+			</para>
+			<section id='lua_class_GRegex_notes'><title>Notes</title>
+				<para>
+					All functions that take a regular expression pattern as an argument will
+					generate an error if that pattern is found invalid by the regex library.
+				</para>
+				<para>
+					All functions that take a string-type regex argument accept a compiled regex
+					too. In this case, the compile flags argument is ignored (should be either supplied as nils or omitted).
+				</para>
+				<para>
+					The capture flag argument 'cf' may also be supplied as a string, whose characters stand for compilation flags.
+					Combinations of the following characters (case sensitive) are supported:
+				    <itemizedlist>
+				    <listitem>
+					    <para> '<command>i</command>' = G_REGEX_CASELESS - Letters in the pattern match both upper- and lowercase letters.
+					    This option can be changed within a pattern by a "(?i)" option setting. </para>
+				    </listitem>
+				    <listitem>
+					    <para> '<command>m</command>' = G_REGEX_MULTILINE - By default, GRegex treats the strings as consisting of a single
+					    line of characters (even if it actually contains newlines). The "start of line"
+					    metacharacter ("^") matches only at the start of the string, while the "end of line"
+					    metacharacter ("$") matches only at the end of the string, or before a terminating newline
+					    (unless G_REGEX_DOLLAR_ENDONLY is set). When G_REGEX_MULTILINE is set, the "start of line"
+					    and "end of line" constructs match immediately following or immediately before any newline
+					    in the string, respectively, as well as at the very start and end. This can be changed
+					    within a pattern by a "(?m)" option setting.</para>
+				    </listitem>
+				    <listitem>
+					    <para> '<command>s</command>' = G_REGEX_DOTALL - A dot metacharater (".") in the pattern matches all characters,
+					    including newlines. Without it, newlines are excluded. This option can be changed within
+					    a pattern by a ("?s") option setting. </para>
+				    </listitem>
+				    <listitem>
+					    <para> '<command>x</command>' = G_REGEX_EXTENDED - Whitespace data characters in the pattern are totally ignored
+					    except when escaped or inside a character class. Whitespace does not include the VT
+					    character (code 11). In addition, characters between an unescaped "#" outside a character
+					    class and the next newline character, inclusive, are also ignored. This can be changed
+					    within a pattern by a "(?x)" option setting. </para>
+				    </listitem>
+				    <listitem>
+					    <para> '<command>U</command>' = G_REGEX_UNGREEDY - Inverts the "greediness" of the quantifiers so that they are not
+					    greedy by default, but become greedy if followed by "?". It can also be set by a "(?U)"
+					    option setting within the pattern. </para>
+				    </listitem>
+				    </itemizedlist>
+				</para>
+			</section><!-- end of notes -->
+			<section id='lua_fn_GRegex_new_pattern_'>
+				<title>GRegex.new(pattern)</title>
+				<para>Compiles regular expression pattern into a regular expression object whose
+			     internal representation is corresponding to the library used. The returned
+			     result then can be used by the methods, e.g. match, exec, etc. Regular
+			     expression objects are automatically garbage collected.
+				</para>
+				<section><title>Arguments</title>
+					<variablelist>
+						<varlistentry><term>pattern</term>
+							<listitem><para> A Perl-compatible regular expression pattern string </para></listitem>
+						</varlistentry> <!-- function_arg_footer: pattern -->
+					</variablelist>
+				</section>
+				<section><title>Returns</title>
+					<para> The compiled regular expression (a userdata object) </para>
+				</section> <!-- function_returns_footer: GRegex.new -->
+				<section><title>Errors</title>
+					<itemizedlist>
+						<listitem><para>A malformed pattern generates a Lua error </para></listitem>
+					</itemizedlist>
+				</section> <!-- function_error_footer: GRegex.new -->
+			</section> <!-- function_footer: GRegex.new -->
+			<section id='lua_fn_GRegex_flags__table__'>
+				<title>GRegex.flags([table])</title>
+				<para>Returns a table containing the numeric values of the constants defined by
+			     the regex library, with the keys being the (string) names of the
+			     constants. If the table argument is supplied then it is used as the
+			     output table, otherwise a new table is created. The constants contained
+			     in the returned table can then be used in most functions and methods where
+			     compilation flags or execution flags can be specified. They can also be
+			     used for comparing with return codes of some functions and methods for
+			     determining the reason of failure.
+			   </para>
+				<section><title>Arguments</title>
+					<variablelist>
+						<varlistentry><term>table (optional)</term>
+							<listitem><para> A table for placing results into </para></listitem>
+						</varlistentry> <!-- function_arg_footer: table (optional) -->
+					</variablelist>
+				</section>
+				<section><title>Returns</title>
+					<para>A table filled with the results.</para>
+				</section> <!-- function_returns_footer: GRegex.flags -->
+			</section> <!-- function_footer: GRegex.flags -->
+			<section id='lua_fn_GRegex_compile_flags__table__'>
+				<title>GRegex.compile_flags([table])</title>
+				<para>Returns a table containing the numeric values of the constants defined by
+					the regex library for compile flags, with the keys being the (string) names of the
+					constants. If the table argument is supplied then it is used as the
+					output table, otherwise a new table is created.
+				</para>
+				<section><title>Arguments</title>
+					<variablelist>
+						<varlistentry><term>table (optional)</term>
+							<listitem><para> A table for placing results into </para></listitem>
+						</varlistentry> <!-- function_arg_footer: table (optional) -->
+					</variablelist>
+				</section>
+				<section><title>Returns</title>
+					<para>A table filled with the results.</para>
+				</section> <!-- function_returns_footer: GRegex.compile_flags -->
+			</section> <!-- function_footer: GRegex.compile_flags -->
+			<section id='lua_fn_GRegex_match_flags__table__'>
+				<title>GRegex.match_flags([table])</title>
+				<para>Returns a table containing the numeric values of the constants defined by
+					the regex library for match flags, with the keys being the (string) names of the
+					constants. If the table argument is supplied then it is used as the
+					output table, otherwise a new table is created.
+				</para>
+				<section><title>Arguments</title>
+					<variablelist>
+						<varlistentry><term>table (optional)</term>
+							<listitem><para> A table for placing results into </para></listitem>
+						</varlistentry> <!-- function_arg_footer: table (optional) -->
+					</variablelist>
+				</section>
+				<section><title>Returns</title>
+					<para>A table filled with the results.</para>
+				</section> <!-- function_returns_footer: GRegex.match_flags -->
+			</section> <!-- function_footer: GRegex.match_flags -->
+			<section id='lua_fn_GRegex_match_subject__pattern___init____cf____ef__'>
+				<title>GRegex.match(subject, pattern, [init], [cf], [ef])</title>
+				<para>Searches for the first match of the regexp pattern in the string subject, starting
+					from offset init, subject to flags cf and ef. The pattern is compiled each time this is
+					called, unlike the class method 'match' function.
+				</para>
+				<section><title>Arguments</title>
+					<variablelist>
+						<varlistentry><term>subject</term>
+							<listitem><para> Subject string to search </para></listitem>
+						</varlistentry> <!-- function_arg_footer: subject -->
+						<varlistentry><term>pattern</term>
+							<listitem><para> A Perl-compatible regular expression pattern string or GRegex object </para></listitem>
+						</varlistentry> <!-- function_arg_footer: pattern -->
+						<varlistentry><term>init (optional)</term>
+							<listitem><para> start offset in the subject (can be negative) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: init (optional) -->
+						<varlistentry><term>cf (optional)</term>
+							<listitem><para> compilation flags (bitwise OR) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: cf (optional) -->
+						<varlistentry><term>ef (optional)</term>
+							<listitem><para> match execution flags (bitwise OR) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: ef (optional) -->
+					</variablelist>
+				</section>
+				<section><title>Returns</title>
+					<para>On success, returns all substring matches ("captures"), in the order they appear in the pattern.
+						false is returned for sub-patterns that did not participate in the match. If
+						the pattern specified no captures then the whole matched substring is
+						returned.  On failure, returns nil.
+					</para>
+				</section> <!-- function_returns_footer: GRegex.match -->
+			</section> <!-- function_footer: GRegex.match -->
+			<section id='lua_fn_GRegex_find_subject__pattern___init____cf____ef__'>
+				<title>GRegex.find(subject, pattern, [init], [cf], [ef])</title>
+				<para>Searches for the first match of the regexp pattern in the string subject, starting
+					from offset init, subject to flags ef. The pattern is compiled each time this is
+					called, unlike the class method 'find' function.
+				</para>
+				<section><title>Arguments</title>
+					<variablelist>
+						<varlistentry><term>subject</term>
+							<listitem><para> Subject string to search </para></listitem>
+						</varlistentry> <!-- function_arg_footer: subject -->
+						<varlistentry><term>pattern</term>
+							<listitem><para> A Perl-compatible regular expression pattern string or GRegex object </para></listitem>
+						</varlistentry> <!-- function_arg_footer: pattern -->
+						<varlistentry><term>init (optional)</term>
+							<listitem><para> start offset in the subject (can be negative) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: init (optional) -->
+						<varlistentry><term>cf (optional)</term>
+							<listitem><para> compilation flags (bitwise OR) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: cf (optional) -->
+						<varlistentry><term>ef (optional)</term>
+							<listitem><para> match execution flags (bitwise OR) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: ef (optional) -->
+					</variablelist>
+				</section>
+				<section><title>Returns</title>
+					<para>On success, returns the start point of the match (a number), the
+						end point of the match (a number), and all substring matches ("captures"), in
+						the order they appear in the pattern. false is returned for sub-patterns that did
+						not participate in the match. On failure, returns nil.
+					</para>
+				</section> <!-- function_returns_footer: GRegex.find -->
+			</section> <!-- function_footer: GRegex.find -->
+			<section id='lua_fn_GRegex_gmatch_subject__pattern___init____cf____ef__'>
+				<title>GRegex.gmatch(subject, pattern, [init], [cf], [ef])</title>
+				<para>Returns an iterator for repeated matching of the pattern patt in the string subj, subject
+					to flags cf and ef. The function is intended for use in the generic for Lua construct.
+					The pattern can be a string or a GRegex object previously compiled with GRegex.new().
+				</para>
+				<section><title>Arguments</title>
+					<variablelist>
+						<varlistentry><term>subject</term>
+							<listitem><para> Subject string to search </para></listitem>
+						</varlistentry> <!-- function_arg_footer: subject -->
+						<varlistentry><term>pattern</term>
+							<listitem><para> A Perl-compatible regular expression pattern string or GRegex object </para></listitem>
+						</varlistentry> <!-- function_arg_footer: pattern -->
+						<varlistentry><term>init (optional)</term>
+							<listitem><para> start offset in the subject (can be negative) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: init (optional) -->
+						<varlistentry><term>cf (optional)</term>
+							<listitem><para> compilation flags (bitwise OR) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: cf (optional) -->
+						<varlistentry><term>ef (optional)</term>
+							<listitem><para> match execution flags (bitwise OR) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: ef (optional) -->
+					</variablelist>
+				</section>
+				<section><title>Returns</title>
+					<para>The iterator function is called by Lua. On every iteration (that is, on every
+						match), it returns all captures in the order they appear in the pattern (or
+						the entire match if the pattern specified no captures). The iteration will
+						continue till the subject fails to match.
+					</para>
+				</section> <!-- function_returns_footer: GRegex.gmatch -->
+			</section> <!-- function_footer: GRegex.gmatch -->
+			<section id='lua_fn_GRegex_gsub_subject__pattern___repl____max____cf____ef__'>
+				<title>GRegex.gsub(subject, pattern, [repl], [max], [cf], [ef])</title>
+				<para>Searches for all matches of the pattern in the string subject and replaces them according
+					to the parameters repl and max.
+					The pattern can be a string or a GRegex object previously compiled with GRegex.new().
+				</para>
+				<para> For details see:
+					<ulink url="http://rrthomas.github.io/lrexlib/manual.html#gsub">http://rrthomas.github.io/lrexlib/manual.html#gsub</ulink>
+				</para>
+				<section><title>Arguments</title>
+					<variablelist>
+						<varlistentry><term>subject</term>
+							<listitem><para> Subject string to search </para></listitem>
+						</varlistentry> <!-- function_arg_footer: subject -->
+						<varlistentry><term>pattern</term>
+							<listitem><para> A Perl-compatible regular expression pattern string or GRegex object </para></listitem>
+						</varlistentry> <!-- function_arg_footer: pattern -->
+						<varlistentry><term>repl (optional)</term>
+							<listitem><para> Substitution source string, function, table, false or nil </para></listitem>
+						</varlistentry> <!-- function_arg_footer: repl (optional) -->
+						<varlistentry><term>max (optional)</term>
+							<listitem><para> Maximum number of matches to search for, or control function, or nil </para></listitem>
+						</varlistentry> <!-- function_arg_footer: max (optional) -->
+						<varlistentry><term>cf (optional)</term>
+							<listitem><para> Compilation flags (bitwise OR) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: cf (optional) -->
+						<varlistentry><term>ef (optional)</term>
+							<listitem><para> Match execution flags (bitwise OR) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: ef (optional) -->
+					</variablelist>
+				</section>
+				<section><title>Returns</title>
+					<para>On success, returns the subject string with the substitutions made,
+						the number of matches found, and the number of substitutions made.
+					</para>
+				</section> <!-- function_returns_footer: GRegex.gsub -->
+			</section> <!-- function_footer: GRegex.gsub -->
+			<section id='lua_fn_GRegex_split_subject__sep___cf____ef__'>
+				<title>GRegex.split(subject, sep, [cf], [ef])</title>
+				<para>Splits a subject string subj into parts (sections). The sep parameter
+					is a regular expression pattern representing separators between the sections.
+					The function is intended for use in the generic for Lua construct.
+					The function returns an iterator for repeated matching of the pattern sep in
+					the string subj, subject to flags cf and ef.
+					The sep pattern can be a string or a GRegex object previously compiled with GRegex.new().
+					Unlike gmatch, there will always be at least one iteration pass, even if there are no matches in the subject.
+				</para>
+				<section><title>Arguments</title>
+					<variablelist>
+						<varlistentry><term>subject</term>
+							<listitem><para> Subject string to search </para></listitem>
+						</varlistentry> <!-- function_arg_footer: subject -->
+						<varlistentry><term>sep</term>
+							<listitem><para> A Perl-compatible regular expression pattern string or GRegex object </para></listitem>
+						</varlistentry> <!-- function_arg_footer: sep -->
+						<varlistentry><term>cf (optional)</term>
+							<listitem><para> compilation flags (bitwise OR) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: cf (optional) -->
+						<varlistentry><term>ef (optional)</term>
+							<listitem><para> match execution flags (bitwise OR) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: ef (optional) -->
+					</variablelist>
+				</section>
+				<section><title>Returns</title>
+					<para>The iterator function is called by Lua. On every iteration, it returns
+						a subject section (can be an empty string), followed by all captures in the order they
+						appear in the sep pattern (or the entire match if the sep pattern specified no captures).
+						If there is no match (this can occur only in the last iteration), then nothing is
+						returned after the subject section. The iteration will continue till the end of the subject.
+					</para>
+				</section> <!-- function_returns_footer: GRegex.split -->
+			</section> <!-- function_footer:  -->
+			<section id='lua_fn_GRegex_version__'>
+				<title>GRegex.version()</title>
+				<para>Returns a returns a string containing the version of the used library.</para>
+				<section><title>Returns</title>
+					<para>The version string</para>
+				</section> <!-- function_returns_footer: GRegex.version -->
+			</section> <!-- function_footer: GRegex.version -->
+			<section id='lua_fn_gregex_match_subject___init____ef__'>
+				<title>gregex:match(subject, [init], [ef])</title>
+				<para>Searches for the first match of the regexp pattern in the string subject, starting
+					from offset init, subject to flags ef.
+				</para>
+				<section><title>Arguments</title>
+					<variablelist>
+						<varlistentry><term>subject</term>
+							<listitem><para> Subject string to search </para></listitem>
+						</varlistentry> <!-- function_arg_footer: subject -->
+						<varlistentry><term>init (optional)</term>
+							<listitem><para> start offset in the subject (can be negative) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: init (optional) -->
+						<varlistentry><term>ef (optional)</term>
+							<listitem><para> match execution flags (bitwise OR) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: ef (optional) -->
+					</variablelist>
+				</section>
+				<section><title>Returns</title>
+					<para>On success, returns all substring matches ("captures"), in the order they appear in the pattern.
+						false is returned for sub-patterns that did not participate in the match. If
+						the pattern specified no captures then the whole matched substring is
+						returned. nil is returned if the pattern did not match.
+					</para>
+				</section> <!-- function_returns_footer: gregex:match -->
+			</section> <!-- function_footer: gregex:match -->
+			<section id='lua_fn_gregex_find_subject___init____ef__'>
+				<title>gregex:find(subject, [init], [ef])</title>
+				<para>Searches for the first match of the regexp pattern in the string subject, starting
+					from offset init, subject to flags ef.
+				</para>
+				<section><title>Arguments</title>
+					<variablelist>
+						<varlistentry><term>subject</term>
+							<listitem><para> Subject string to search </para></listitem>
+						</varlistentry> <!-- function_arg_footer: subject -->
+						<varlistentry><term>init (optional)</term>
+							<listitem><para> start offset in the subject (can be negative) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: init (optional) -->
+						<varlistentry><term>ef (optional)</term>
+							<listitem><para> match execution flags (bitwise OR) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: ef (optional) -->
+					</variablelist>
+				</section>
+				<section><title>Returns</title>
+					<para>On success, returns the start point of the match (a number), the
+						end point of the match (a number), and all substring matches ("captures"), in
+						the order they appear in the pattern. false is returned for sub-patterns that did
+						not participate in the match. On failure, returns nil.
+					</para>
+				</section> <!-- function_returns_footer: gregex:find -->
+			</section> <!-- function_footer:  -->
+			<section id='lua_fn_gregex_exec_subject___init____ef__'>
+				<title>gregex:exec(subject, [init], [ef])</title>
+				<para>Searches for the first match of the compiled GRegex object in the string subject, starting
+					from offset init, subject to the execution match flags ef.
+				</para>
+				<section><title>Arguments</title>
+					<variablelist>
+						<varlistentry><term>subject</term>
+							<listitem><para> Subject string to search </para></listitem>
+						</varlistentry> <!-- function_arg_footer: subject -->
+						<varlistentry><term>init (optional)</term>
+							<listitem><para> start offset in the subject (can be negative) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: init (optional) -->
+						<varlistentry><term>ef (optional)</term>
+							<listitem><para> match execution flags (bitwise OR) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: ef (optional) -->
+					</variablelist>
+				</section>
+				<section><title>Returns</title>
+					<para>On success, returns the start point of the first match (a number), the
+					end point of the first match (a number), and the offsets of substring matches ("captures"
+					in Lua terminology) are returned as a third result, in a table. This table contains false
+					in the positions where the corresponding sub-pattern did not participate in the match.
+					On failure, returns nil.
+					Example:
+					  If the whole match is at offsets 10,20 and substring matches are at offsets 12,14 and 16,19
+					  then the function returns the following: 10, 20, { 12,14,16,19 }.
+					</para>
+				</section> <!-- function_returns_footer: gregex:exec -->
+			</section> <!-- function_footer: gregex:exec -->
+			<section id='lua_fn_gregex_dfa_exec_subject___init____ef__'>
+				<title>gregex:dfa_exec(subject, [init], [ef])</title>
+				<para>Matches a compiled regular expression GRegex object against a given subject string subj, using a DFA matching algorithm.</para>
+				<section><title>Arguments</title>
+					<variablelist>
+						<varlistentry><term>subject</term>
+							<listitem><para> Subject string to search </para></listitem>
+						</varlistentry> <!-- function_arg_footer: subject -->
+						<varlistentry><term>init (optional)</term>
+							<listitem><para> start offset in the subject (can be negative) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: init (optional) -->
+						<varlistentry><term>ef (optional)</term>
+							<listitem><para> match execution flags (bitwise OR) </para></listitem>
+						</varlistentry> <!-- function_arg_footer: ef (optional) -->
+					</variablelist>
+				</section>
+				<section><title>Returns</title>
+					<para>On success, returns the start point of the matches found (a number), a
+						table containing the end points of the matches found, the longer matches first, and the
+						number of matches found as the third return value.
+						On failure, returns nil.
+						Example:
+						  If there are 3 matches found starting at offset 10 and ending at offsets 15, 20 and 25
+						  then the function returns the following: 10, { 25,20,15 }, 3
+					</para>
+				</section> <!-- function_returns_footer: gregex:dfa_exec -->
+			</section> <!-- function_footer: gregex:dfa_exec -->
+			<section id='lua_fn_gregex___tostring__'>
+				<title>gregex:__tostring()</title>
+				<para>Returns a string containing debug information about the GRegex object.</para>
+				<section><title>Returns</title>
+					<para>The debug string</para>
+				</section> <!-- function_returns_footer: gregex:__tostring -->
+			</section> <!-- function_footer:  -->
+		</section> <!-- class_footer: GRegex -->
+	</section>
+
+
 </chapter>