WoW:Pattern matching - Revision history

Move page script: Move page script moved page Pattern matching to WoW:Pattern matching without leaving a redirect

2023-08-15T04:48:53Z

Move page script moved page Pattern matching to Pattern matching without leaving a redirect

← Older revision	Revision as of 04:48, 15 August 2023
(No difference)

Bear at 08:45, 21 May 2020

2020-05-21T08:45:05Z

← Older revision		Revision as of 08:45, 21 May 2020
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			{{wowlua}}
	A '''regular expression''' is a formula for matching strings that follow some pattern. The formula (and syntax used) varies depending on the method of searching used. [[Lua]], the scripting language that World of Warcraft uses, does not support regular expressions. Instead, it offers a basic pattern-matching mechanism with most of the features of REs. Though since Lua doesn't implement regexes, at all, but rather "patterns", this can confuse more than it helps. Better refer to the official Lua documentation (which never mentions "regular expressions").		A '''regular expression''' is a formula for matching strings that follow some pattern. The formula (and syntax used) varies depending on the method of searching used. [[Lua]], the scripting language that World of Warcraft uses, does not support regular expressions. Instead, it offers a basic pattern-matching mechanism with most of the features of REs. Though since Lua doesn't implement regexes, at all, but rather "patterns", this can confuse more than it helps. Better refer to the official Lua documentation (which never mentions "regular expressions").

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	[http://www.lua.org/manual/5.0/manual.html#5.3 Lua.org] - Good manual		[http://www.lua.org/manual/5.0/manual.html#5.3 Lua.org] - Good manual
	[http://lua-users.org/wiki/PatternsTutorial Lua-users.org] - Wiki		[http://lua-users.org/wiki/PatternsTutorial Lua-users.org] - Wiki

	[[Category:Glossary]]		[[Category:Glossary]]
	[[Category:HOWTOs]]		[[Category:HOWTOs]]
			[[Category:Lua]]

93.177.181.200: /* "Regexes" (patterns) in Lua */ gsub was replaced with gmatch

2015-03-28T23:11:38Z

"Regexes" (patterns) in Lua: gsub was replaced with gmatch

← Older revision		Revision as of 23:11, 28 March 2015
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	* [[API_strfind\|string.find]](string, pattern) -- finds the first instance of pattern in string		* [[API_strfind\|string.find]](string, pattern) -- finds the first instance of pattern in string
	* string.gfind(string, pattern) -- when called repeatedly, finds each successive instance of pattern in string		* string.gfind(string, pattern) -- when called repeatedly, finds each successive instance of pattern in string
	* [[API gsub\|string.~~gsub~~]](string, pattern, repl) -- returns a string where all instances of pattern in string have been replaced with repl		* [[API gsub\|string.gmatch]](string, pattern, repl) -- returns a string where all instances of pattern in string have been replaced with repl
	* [[API strmatch\|string.match]](string, pattern, init) -- Returns a list of matches of pattern in string, starting search at init (1 is the first character of string, 2 is the second, etc.).		* [[API strmatch\|string.match]](string, pattern, init) -- Returns a list of matches of pattern in string, starting search at init (1 is the first character of string, 2 is the second, etc.).

WoWWiki>Egingell: /* Constructing a pattern */ I don't know how that little caveat was missed.

2010-08-09T11:25:48Z

Constructing a pattern: I don't know how that little caveat was missed.

← Older revision		Revision as of 11:25, 9 August 2010
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	* %x --- represents all hexadecimal digits.		* %x --- represents all hexadecimal digits.
	* %z --- represents the character with representation 0. Note that embedded zeroes in a pattern will not work. Use this instead.		* %z --- represents the character with representation 0. Note that embedded zeroes in a pattern will not work. Use this instead.
			The upper cased version of the above reverses the meaning of said (i.e. %A --- represents all ''non''-letters).
	* %x (where x is any non-alphanumeric character) --- represents the character x. This is the standard way to escape the magic characters. Any punctuation character (even the non magic) can be preceded by a '%' when used to represent itself in a pattern.		* %x (where x is any non-alphanumeric character) --- represents the character x. This is the standard way to escape the magic characters. Any punctuation character (even the non magic) can be preceded by a '%' when used to represent itself in a pattern.
	* [set] --- represents the class which is the union of all characters in set. A range of characters may be specified by separating the end characters of the range with a '-'. All classes %x described above may also be used as components in set. All other characters in set represent themselves. For example, [%w_] (or [_%w]) represents all alphanumeric characters plus the underscore.		* [set] --- represents the class which is the union of all characters in set. A range of characters may be specified by separating the end characters of the range with a '-'. All classes %x described above may also be used as components in set. All other characters in set represent themselves. For example, [%w_] (or [_%w]) represents all alphanumeric characters plus the underscore.

WoWWiki>Sesshu: /* Constructing a pattern */

2009-07-08T21:10:54Z

Constructing a pattern

← Older revision		Revision as of 21:10, 8 July 2009
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	* %x --- represents all hexadecimal digits.		* %x --- represents all hexadecimal digits.
	* %z --- represents the character with representation 0. Note that embedded zeroes in a pattern will not work. Use this instead.		* %z --- represents the character with representation 0. Note that embedded zeroes in a pattern will not work. Use this instead.
	* %x (where x is any non-alphanumeric character) --- represents the character x. This is the standard way to escape the magic characters. Any punctuation character (even the non magic) can be preceded by a `%´ when used to represent itself in a pattern.		* %x (where x is any non-alphanumeric character) --- represents the character x. This is the standard way to escape the magic characters. Any punctuation character (even the non magic) can be preceded by a '%' when used to represent itself in a pattern.
	* [set] --- represents the class which is the union of all characters in set. A range of characters may be specified by separating the end characters of the range with a `-´. All classes %x described above may also be used as components in set. All other characters in set represent themselves. For example, [%w_] (or [_%w]) represents all alphanumeric characters plus the underscore.		* [set] --- represents the class which is the union of all characters in set. A range of characters may be specified by separating the end characters of the range with a '-'. All classes %x described above may also be used as components in set. All other characters in set represent themselves. For example, [%w_] (or [_%w]) represents all alphanumeric characters plus the underscore.
	* [^set] --- represents the complement of set, where set is interpreted as above.		* [^set] --- represents the complement of set, where set is interpreted as above.

WoWWiki>Egingell: /* "Regexes" (patterns) in Lua */

2009-05-18T00:01:05Z

"Regexes" (patterns) in Lua

← Older revision		Revision as of 00:01, 18 May 2009
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	* [[API_strfind\|string.find]](string, pattern) -- finds the first instance of pattern in string		* [[API_strfind\|string.find]](string, pattern) -- finds the first instance of pattern in string
	* string.gfind(string, pattern) -- when called repeatedly, finds each successive instance of pattern in string		* string.gfind(string, pattern) -- when called repeatedly, finds each successive instance of pattern in string
	* string.gsub(string, pattern, repl) -- returns a string where all instances of pattern in string have been replaced with repl		* [[API gsub\|string.gsub]](string, pattern, repl) -- returns a string where all instances of pattern in string have been replaced with repl
	* string.match(string, pattern, init) -- Returns ~~match~~ of pattern in string, starting search at init.		* [[API strmatch\|string.match]](string, pattern, init) -- Returns a list of matches of pattern in string, starting search at init (1 is the first character of string, 2 is the second, etc.).

	== Constructing a pattern ==		== Constructing a pattern ==

WoWWiki>Gotai: /* "Regexes" (patterns) in Lua */ Corrected wrong description of string.match

2009-05-17T13:21:39Z

"Regexes" (patterns) in Lua: Corrected wrong description of string.match

← Older revision		Revision as of 13:21, 17 May 2009
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	* string.gfind(string, pattern) -- when called repeatedly, finds each successive instance of pattern in string		* string.gfind(string, pattern) -- when called repeatedly, finds each successive instance of pattern in string
	* string.gsub(string, pattern, repl) -- returns a string where all instances of pattern in string have been replaced with repl		* string.gsub(string, pattern, repl) -- returns a string where all instances of pattern in string have been replaced with repl
	* string.match(string, pattern, ~~limit~~) -- ~~returns a list~~ of ~~matches up to limit or all of them if no limit passed~~		* string.match(string, pattern, init) -- Returns match of pattern in string, starting search at init.

	== Constructing a pattern ==		== Constructing a pattern ==

WoWWiki>Cralor at 01:11, 3 December 2008

2008-12-03T01:11:52Z

← Older revision		Revision as of 01:11, 3 December 2008
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	Patterns may also have subpatterns. These are enclosed with () and are counted as matches are found. They can be accessed using the %n element mentioned above. Using the empty capture "()" will return the string position where a match is found.		Patterns may also have subpatterns. These are enclosed with () and are counted as matches are found. They can be accessed using the %n element mentioned above. Using the empty capture "()" will return the string position where a match is found.

			== Pattern Items ==
			* a single character class, which matches any single character in the class;
			* a single character class followed by `*´, which matches 0 or more repetitions of characters in the class. These repetition items will always match the longest possible sequence;
			* a single character class followed by `+´, which matches 1 or more repetitions of characters in the class. These repetition items will always match the longest possible sequence;
			* a single character class followed by `-´, which also matches 0 or more repetitions of characters in the class. Unlike `*´, these repetition items will always match the shortest possible sequence;
			* a single character class followed by `?´, which matches 0 or 1 occurrence of a character in the class;
			* %n, for n between 1 and 9; such item matches a substring equal to the n-th captured string (see below);
			* %bxy, where x and y are two distinct characters; such item matches strings that start with x, end with y, and where the x and y are balanced. This means that, if one reads the string from left to right, counting +1 for an x and -1 for a y, the ending y is the first y where the count reaches 0. For instance, the item %b() matches expressions with balanced parentheses.
			[http://www.lua.org/manual/5.0/manual.html#5.3 Source]
	== Example ==		== Example ==
	Say we're writing a function that watches the combat chat and counts the number of times a murloc dies nearby (don't we all want this? :) ). So, how do we do this? (incidentally, I have done this. It was quite satisfying)		Say we're writing a function that watches the combat chat and counts the number of times a murloc dies nearby (don't we all want this? :) ). So, how do we do this? (incidentally, I have done this. It was quite satisfying)

WoWWiki>Tuhljin at 15:10, 21 October 2008

2008-10-21T15:10:52Z

← Older revision		Revision as of 15:10, 21 October 2008
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	Lua has a few string functions that use patterns (what some people mistakenly call regexes). Among them are		Lua has a few string functions that use patterns (what some people mistakenly call regexes). Among them are

	* string.find(string, pattern) -- finds the first instance of pattern in string		* [[API_strfind\|string.find]](string, pattern) -- finds the first instance of pattern in string
	* string.gfind(string, pattern) -- when called repeatedly, finds each successive instance of pattern in string		* string.gfind(string, pattern) -- when called repeatedly, finds each successive instance of pattern in string
	* string.gsub(string, pattern, repl) -- returns a string where all instances of pattern in string have been replaced with repl		* string.gsub(string, pattern, repl) -- returns a string where all instances of pattern in string have been replaced with repl

WoWWiki>Sky2042: overall tweaks

2008-08-31T02:03:23Z

overall tweaks

@@ Line 1: / Line 1: @@
-A formula for matching strings that follow some pattern. The formula (and syntax used) varies depending on the method of searching used. [[Lua]], the scripting language that World of Warcraft uses, does not support regular expressions. Instead, it offers a basic pattern-matching mechanism with most of the features of REs.
+A '''regular expression''' is a formula for matching strings that follow some pattern. The formula (and syntax used) varies depending on the method of searching used. [[Lua]], the scripting language that World of Warcraft uses, does not support regular expressions. Instead, it offers a basic pattern-matching mechanism with most of the features of REs. Though since Lua doesn't implement regexes, at all, but rather "patterns", this can confuse more than it helps.  Better refer to the official Lua documentation (which never mentions "regular expressions").
-A very good introduction to regexes can be found here: [http://www.castaglia.org/proftpd/doc/contrib/regexp.html Regular Expressions Explained]
+== "Regexes" (patterns) in Lua ==
-See also:
+* string.find(string, pattern) -- finds the first instance of pattern in string
-* [[HOWTO: Use Pattern Matching]]
+* string.gfind(string, pattern) -- when called repeatedly, finds each successive instance of pattern in string
 [[Category:Glossary]]