Module:String

Module:String (edit | talk | history | links | watch | logs)

This module is intended to provide access to basic string functions.

Most of the functions provided here can be invoked with named parameters, unnamed parameters, or a mixture. If named parameters are used, Mediawiki will automatically remove any leading or trailing whitespace from the parameter. Depending on the intended use, it may be advantageous to either preserve or remove such whitespace.

Global options

ignore_errors

If set to 'true' or 1, any error condition will result in an empty string being returned rather than an error message.

error_category

If an error occurs, specifies the name of a category to include with the error message. The default category is Category:Errors reported by Module String (0).

no_category

If set to 'true' or 1, no category will be added if an error is generated.

Unit tests for this module are available at Module:String/testcases.

len

This function returns the length of the target string.

Usage:

{{#invoke:String|len|target_string}}

OR

{{#invoke:String|len|s= target_string }}

Parameters:

s

The string whose length to report

Examples:

• {{#invoke:String|len| abcdefghi }} → 11
• {{#invoke:String|len|s= abcdefghi }} → 9

sub

This function returns a substring of the target string at specified inclusive, one-indexed indices.

Usage:

{{#invoke:String|sub|target_string|start_index|end_index}}

OR

{{#invoke:String|sub|s= target_string |i= start_index |j= end_index }}

Parameters:

s

The string to return a subset of

i

The first index of the substring to return, defaults to 1.

j

The last index of the string to return, defaults to the last character.

The first character of the string is assigned an index of 1. If either i or j is a negative value, it is interpreted the same as selecting a character by counting from the end of the string. Hence, a value of -1 is the same as selecting the last character of the string.

If the requested indices are out of range for the given string, an error is reported. To avoid error messages, use {{#invoke:ustring|sub}} instead.

Examples:

• "{{#invoke:String|sub| abcdefghi }}" → " abcdefghi "
• "{{#invoke:String|sub|s= abcdefghi }}" → "abcdefghi"
• "{{#invoke:String|sub| abcdefghi | 3 }}" → "bcdefghi "
• "{{#invoke:String|sub|s= abcdefghi |i= 3 }}" → "cdefghi"
• "{{#invoke:String|sub| abcdefghi | 3 | 4 }}" → "bc"
• "{{#invoke:String|sub|s= abcdefghi |i= 3 |j= 4 }}" → "cd"

sublength

This function implements the features of {{str sub old}} and is kept in order to maintain these older templates. It returns a substring of the target string starting at a specified index and of a specified length.

Usage:

{{#invoke:String|sublength|s= target_string |i= start_index |len= length }}

Parameters:

s

The string

i

The starting index of the substring to return. The first character of the string is assigned an index of 0.

len

The length of the string to return, defaults to the last character.

Examples:

• {{#invoke:String|sublength|s= abcdefghi }} → abcdefghi
• {{#invoke:String|sublength|s= abcdefghi |i= 3 }} → defghi
• {{#invoke:String|sublength|s= abcdefghi |i= 3 |len= 4 }} → defg

match

This function returns a substring from the source string that matches a specified pattern.

Usage:

{{#invoke:String|match|source_string|pattern_string|start_index|match_number|plain_flag|nomatch_output}}

OR

{{#invoke:String|match|s= source_string |pattern= pattern_string |start= start_index |match= match_number |plain= plain_flag |nomatch= nomatch_output }}

Parameters:

s

The string to search

pattern

The pattern or string to find within the string

start

The index within the source string to start the search. The first character of the string has index 1. Defaults to 1.

match

In some cases it may be possible to make multiple matches on a single string. This specifies which match to return, where the first match is match= 1. If a negative number is specified then a match is returned counting from the last match. Hence match = -1 is the same as requesting the last match. Defaults to 1.

plain

Boolean flag indicating that pattern should be understood as plain text and not as a Scribunto ustring pattern (a unicode-friendly Lua-style regular expression). Defaults to false (to change: plain=true)

nomatch

If no match is found, output the "nomatch" value rather than an error.

ignore_errors

If no match is found and ignore_errors=true, output an empty string rather than an error.

If the match_number or start_index are out of range for the string being queried, then this function generates an error. An error is also generated if no match is found. If one adds the parameter ignore_errors=true, then the error will be suppressed and an empty string will be returned on any failure.

For information on constructing Lua patterns, a form of regular expression, see:

• Scribunto patterns
• Scribunto Unicode string patterns

Examples:

• {{#invoke:String|match| abc123def456 |%d+}} → 123
• {{#invoke:String|match|s= abc123def456 |pattern= %d+ }} → 123
• {{#invoke:String|match| abc123def456 |%d+|6}} → 23
• {{#invoke:String|match|s= abc123def456 |pattern= %d+ |start= 6 }} → 3
• {{#invoke:String|match|s= abc123def456 |pattern= %d+ |start= 6 |match= 2 }} → 456
• {{#invoke:String|match|s= abc123%d+ |pattern= %d+ }} → 123
• {{#invoke:String|match|s= abc123%d+ |pattern= %d+ |plain= true }} → %d+
• {{#invoke:String|match|s= abc |pattern= %d }} →
• {{#invoke:String|match|s= abc |pattern= %d |nomatch= No numeric characters in string }} → No numeric characters in string
• {{#invoke:String|match|s= abc |pattern= %d |ignore_errors= true }} →
• {{#invoke:String|match|s= 0012001200 |pattern= 0*(%d*) }} → 12001200

pos

This function returns a single character from the target string at position pos.

Usage:

{{#invoke:String|pos|target_string|index_value}}

OR

{{#invoke:String|pos|target= target_string |pos= index_value }}

Parameters:

target

The string to search

pos

The index for the character to return

The first character has an index value of 1.

If one requests a negative value, this function will select a character by counting backwards from the end of the string. In other words pos = -1 is the same as asking for the last character.

A requested value of zero, or a value greater than the length of the string returns an error.

Examples:

• {{#invoke:String|pos| abcdefghi | 4 }} → c
• {{#invoke:String|pos|target= abcdefghi |pos= 4 }} → d

str_find

This function duplicates the behavior of {{str_find}}, including all of its quirks. This is provided in order to support existing templates, but is NOT RECOMMENDED for new code and templates. New code is recommended to use the "find" function instead.

Returns the first index in "source" that is a match to "target". Indexing is 1-based, and the function returns -1 if the "target" string is not present in "source".

Important Note: If the "target" string is empty / missing, this function returns a value of "1", which is generally unexpected behavior, and must be accounted for separately.

Usage:

{{#invoke:String|str_find|source_string|target_string}}

OR

{{#invoke:String|str_find|source= source_string |target= target_string }}

Parameters:

source

The string to search

target

The string to find within source

Examples:

• {{#invoke:String|str_find| abc123def }} →
• {{#invoke:String|str_find|source= abc123def }} →
• {{#invoke:String|str_find| abc123def |123}} →
• {{#invoke:String|str_find|source= abc123def |target= 123 }} →
• {{#invoke:String|str_find| abc123def |not}} →

find

This function allows one to search for a target string or pattern within another string.

Usage:

{{#invoke:String|find|source_string|target_string|start_index|plain_flag}}

OR

{{#invoke:String|find|source= source_string |target= target_string |start= start_index |plain= plain_flag }}

Parameters:

source

The string to search

target

The string or pattern to find within source

start

The index within the source string to start the search, defaults to 1

plain

Boolean flag indicating that target should be understood as plain text and not as a Scribunto ustring pattern (a unicode-friendly Lua-style regular expression); defaults to true

This function returns the first index >= "start" where "target" can be found within "source". Indices are 1-based. If "target" is not found, then this function returns 0. If either "source" or "target" are missing / empty, this function also returns 0.

This function should be safe for UTF-8 strings.

Examples:

• {{#invoke:String|find|abc123def|12}} → 4

• {{#invoke:String|find|source=abc123def|target=12}} → 4

• {{#invoke:String|find|source=abc123def|target=pqr}} → 0

• {{#invoke:String|find| abc123def |123}} → 5
• {{#invoke:String|find|source= abc123def |target= 123 }} → 4
• {{#invoke:String|find|source=abc123def|target=%d |start=3 |plain=false }} → 4

When using unnamed parameters, preceding and trailing spaces are kept and counted:

• {{#invoke:String|find| abc123def |c|false}} → 5
• {{#invoke:String|find|source= abc123def |target=c|plain=false}} → 3
• {{#invoke:string|find|abc 123 def|%s|plain=false}} → 4

Testing for the presence of a string:

• {{#ifexpr:{{#invoke:string|find|haystack|needle}}|Found needle|Didn't find needle}} → Didn't find needle

replace (gsub)

This function allows one to replace a target string or pattern within another string. To Lua programmers: this function works internally by calling <syntaxhighlight lang="text" class="" id="" style="" inline="1">string.gsub</syntaxhighlight>.

Usage:

{{#invoke:String|replace|source_str|pattern_string|replace_string|replacement_count|plain_flag}}

OR

{{#invoke:String|replace|source= source_string |pattern= pattern_string |replace= replace_string |count= replacement_count |plain= plain_flag }}

Parameters:

source

The string to search

pattern

The string or pattern to find within source

replace

The replacement text

count

The number of occurrences to replace; defaults to all

plain

Boolean flag indicating that pattern should be understood as plain text and not as a Scribunto ustring pattern (a unicode-friendly Lua-style regular expression); defaults to true

Examples:

• "{{#invoke:String|replace| abc123def456 |123|XYZ}}" → " abcXYZdef456 "
• "{{#invoke:String|replace|source= abc123def456 |pattern= 123 |replace= XYZ }}" → "abcXYZdef456"
• "{{#invoke:String|replace| abc123def456 |%d+|XYZ|1|false}}" → " abcXYZdef456 "
• "{{#invoke:String|replace|source= abc123def456 |pattern= %d+ |replace= XYZ |count=1 |plain= false }}" → "abcXYZdef456"
• "{{#invoke:String|replace|source= abc123def456 |pattern= %d+ |replace= XYZ |plain= false }}" → "abcXYZdefXYZ"
• {{#invoke:String|replace|source= 0012001200 |pattern= ^0* |plain= false }} → 12001200

rep

Repeats a string n times. A simple function to pipe string.rep to templates.

Usage:

{{#invoke:String|rep|source|count}}

Parameters:

source

The string to repeat

count

The number of repetitions.

Examples:

• "{{#invoke:String|rep|hello|3}}" → "hellohellohello"
• "{{#invoke:String|rep| hello | 3 }}" → " hello hello hello "

escapePattern

In a Lua pattern, changes a class character into a literal character. For example: in a pattern, character . catches "any character"; escapePattern will convert it to %., catching just the literal character ".".

Usage:

• {{#invoke:String|escapePattern|pattern_string}}

Parameters:

pattern_string

The pattern string to escape

Examples:

• "{{#invoke:String|escapePattern|A.D.}}" → ""
• "{{#invoke:String|escapePattern|10%}}" → ""

count

Counts the number of times a given pattern appears in the arguments that get passed on to this module. Counts disjoint matches only.

Usage:

{{#invoke:String|count|source_str|pattern_string|plain_flag}}

OR

{{#invoke:String|count|source= source_string |pattern= pattern_string|plain= plain_flag }}

Parameters:

source_string

The string to count occurrences in

pattern

The string or pattern to count occurrences of within source

plain

Boolean flag indicating that pattern should be understood as plain text and not as a Scribunto ustring pattern (a unicode-friendly Lua-style regular expression); defaults to true

Examples:

• Count of 'a': "{{#invoke:String|count|aabbcc|a}}" → "2"
• Count occurrences of 'aba': "{{#invoke:String|count|ababababab|aba}}" → "2"
• Count of "either 'a' or 'c' ":"{{#invoke:String|count|aabbcc|[ac]|plain=false}}" → "4"
• Count of "not 'a' ": "{{#invoke:String|count|aaabaaac|[^a]|plain=false}}" → "2"
• Count of "starts with 'a' ": "{{#invoke:String|count|aaabaaac|^a|plain=false}}" → "1"

join

Joins all strings passed as arguments into one string, treating the first argument as a separator

Usage:

{{#invoke:String|join|separator|string1|string2|...}}

Parameters:

separator

String that separates each string being joined together

Note that leading and trailing spaces are not stripped from the separator.

string1/string2/...

Strings being joined together

Examples:

• "{{#invoke:String|join|x|foo|bar|baz}}" → ""
• "{{#invoke:String|join||a|b|c|d|e|f|g}}" → ""
• "{{#invoke:String|join|,|a|b|c|d|e|f|g}}" → ""
• "{{#invoke:String|join|, |a|b|c|d|e|f|g}}" → ""
• "{{#invoke:String|join| – |a|b|c|d|e|f|g}}" → ""

The preceding example uses the html entity &ndash; but the unicode character also works.

endswith

For the startswith function, see Module:String2 § startswith.

Usage:

{{#invoke:String|endswith|source_str|search_string}}

OR

{{#invoke:String|endswith|source= source_string |pattern= search_string}}

Returns "yes" if the source string ends with the search string. Use named parameters to have the strings trimmed before use. Despite the parameter name, search_string is not a Lua pattern, it is interpreted literally.

• "{{#invoke:String|endswith|xxxyyy|y}}" → ""
• "{{#invoke:String|endswith|xxxyyy|z}}" → ""

See also

---

--[[

This module is intended to provide access to basic string functions.

Most of the functions provided here can be invoked with named parameters,
unnamed parameters, or a mixture.  If named parameters are used, Mediawiki will
automatically remove any leading or trailing whitespace from the parameter.
Depending on the intended use, it may be advantageous to either preserve or
remove such whitespace.

Global options
	ignore_errors: If set to 'true' or 1, any error condition will result in
		an empty string being returned rather than an error message.
		
	error_category: If an error occurs, specifies the name of a category to
		include with the error message.  The default category is
		[Category:Errors reported by Module String].
		
	no_category: If set to 'true' or 1, no category will be added if an error
		is generated.
		
Unit tests for this module are available at Module:String/tests.
]]

local str = {}

--[[
len

This function returns the length of the target string.

Usage:
{{#invoke:String|len|target_string|}}
OR
{{#invoke:String|len|s=target_string}}

Parameters
	s: The string whose length to report

If invoked using named parameters, Mediawiki will automatically remove any leading or
trailing whitespace from the target string.
]]
function str.len( frame )
	local new_args = str._getParameters( frame.args, {'s'} )
	local s = new_args['s'] or ''
	return mw.ustring.len( s )
end

--[[
sub

This function returns a substring of the target string at specified indices.

Usage:
{{#invoke:String|sub|target_string|start_index|end_index}}
OR
{{#invoke:String|sub|s=target_string|i=start_index|j=end_index}}

Parameters
	s: The string to return a subset of
	i: The fist index of the substring to return, defaults to 1.
	j: The last index of the string to return, defaults to the last character.
	
The first character of the string is assigned an index of 1.  If either i or j
is a negative value, it is interpreted the same as selecting a character by
counting from the end of the string.  Hence, a value of -1 is the same as
selecting the last character of the string.

If the requested indices are out of range for the given string, an error is
reported.
]]
function str.sub( frame )
	local new_args = str._getParameters( frame.args, { 's', 'i', 'j' } )
	local s = new_args['s'] or ''
	local i = tonumber( new_args['i'] ) or 1
	local j = tonumber( new_args['j'] ) or -1
	
	local len = mw.ustring.len( s )

	-- Convert negatives for range checking
	if i < 0 then
		i = len + i + 1
	end
	if j < 0 then
		j = len + j + 1
	end
	
	if i > len or j > len or i < 1 or j < 1 then
		return str._error( 'String subset index out of range' )
	end
	if j < i then
		return str._error( 'String subset indices out of order' )
	end
	
	return mw.ustring.sub( s, i, j )
end

--[[
This function implements that features of {{str sub old}} and is kept in order
to maintain these older templates.
]]
function str.sublength( frame )
	local i = tonumber( frame.args.i ) or 0
	local len = tonumber( frame.args.len )
	return mw.ustring.sub( frame.args.s, i + 1, len and ( i + len ) )
end

--[[
match

This function returns a substring from the source string that matches a
specified pattern.

Usage:
{{#invoke:String|match|source_string|pattern_string|start_index|match_number|plain_flag|nomatch_output}}
OR
{{#invoke:String|pos|s=source_string|pattern=pattern_string|start=start_index
	|match=match_number|plain=plain_flag|nomatch=nomatch_output}}

Parameters
	s: The string to search
	pattern: The pattern or string to find within the string
	start: The index within the source string to start the search.  The first
		character of the string has index 1.  Defaults to 1.
	match: In some cases it may be possible to make multiple matches on a single
		string.  This specifies which match to return, where the first match is
		match= 1.  If a negative number is specified then a match is returned
		counting from the last match.  Hence match = -1 is the same as requesting
		the last match.  Defaults to 1.
	plain: A flag indicating that the pattern should be understood as plain
		text.  Defaults to false.
	nomatch: If no match is found, output the "nomatch" value rather than an error.

If invoked using named parameters, Mediawiki will automatically remove any leading or
trailing whitespace from each string.  In some circumstances this is desirable, in
other cases one may want to preserve the whitespace.

If the match_number or start_index are out of range for the string being queried, then
this function generates an error.  An error is also generated if no match is found.
If one adds the parameter ignore_errors=true, then the error will be suppressed and
an empty string will be returned on any failure.

For information on constructing Lua patterns, a form of [regular expression], see:

* http://www.lua.org/manual/5.1/manual.html#5.4.1
* http://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#Patterns
* http://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#Ustring_patterns

]]
function str.match( frame )
	local new_args = str._getParameters( frame.args, {'s', 'pattern', 'start', 'match', 'plain', 'nomatch'} )
	local s = new_args['s'] or ''
	local start = tonumber( new_args['start'] ) or 1
	local plain_flag = str._getBoolean( new_args['plain'] or false )
	local pattern = new_args['pattern'] or ''
	local match_index = math.floor( tonumber(new_args['match']) or 1 )
	local nomatch = new_args['nomatch']
	
	if s == '' then
		-- return str._error( 'Target string is empty' )
	end
	if pattern == '' then
		return str._error( 'Pattern string is empty' )
	end
	if math.abs(start) < 1 or math.abs(start) > mw.ustring.len( s ) then
		-- return str._error( 'Requested start is out of range' )
	end
	if match_index == 0 then
		return str._error( 'Match index is out of range' )
	end
	if plain_flag then
		pattern = str._escapePattern( pattern )
	end
	
	local result
	if match_index == 1 then
		-- Find first match is simple case
		result = mw.ustring.match( s, pattern, start )
	else
		if start > 1 then
			s = mw.ustring.sub( s, start )
		end
		
		local iterator = mw.ustring.gmatch(s, pattern)
		if match_index > 0 then
			-- Forward search
			for w in iterator do
				match_index = match_index - 1
				if match_index == 0 then
					result = w
					break
				end
			end
		else
			-- Reverse search
			local result_table = {}
			local count = 1
			for w in iterator do
				result_table[count] = w
				count = count + 1
			end
			
			result = result_table[ count + match_index ]
		end
	end
	
	if result == nil then
		if nomatch == nil then
			return str._error( 'Match not found' )
		else
			return nomatch
		end
	else
		return result
	end
end

--[[
pos

This function returns a single character from the target string at position pos.

Usage:
{{#invoke:String|pos|target_string|index_value}}
OR
{{#invoke:String|pos|target=target_string|pos=index_value}}

Parameters
	target: The string to search
	pos: The index for the character to return

If invoked using named parameters, Mediawiki will automatically remove any leading or
trailing whitespace from the target string.  In some circumstances this is desirable, in
other cases one may want to preserve the whitespace.

The first character has an index value of 1.

If one requests a negative value, this function will select a character by counting backwards
from the end of the string.  In other words pos = -1 is the same as asking for the last character.

A requested value of zero, or a value greater than the length of the string returns an error.
]]
function str.pos( frame )
	local new_args = str._getParameters( frame.args, {'target', 'pos'} )
	local target_str = new_args['target'] or ''
	local pos = tonumber( new_args['pos'] ) or 0

	if pos == 0 or math.abs(pos) > mw.ustring.len( target_str ) then
		return str._error( 'String index out of range' )
	end
	
	return mw.ustring.sub( target_str, pos, pos )
end

--[[
find

This function allows one to search for a target string or pattern within another
string.

Usage:
{{#invoke:String|find|source_str|target_string|start_index|plain_flag}}
OR
{{#invoke:String|find|source=source_str|target=target_str|start=start_index|plain=plain_flag}}

Parameters
	source: The string to search
	target: The string or pattern to find within source
	start: The index within the source string to start the search, defaults to 1
	plain: Boolean flag indicating that target should be understood as plain
		text and not as a Lua style regular expression, defaults to true

If invoked using named parameters, Mediawiki will automatically remove any leading or
trailing whitespace from the parameter.  In some circumstances this is desirable, in
other cases one may want to preserve the whitespace.

This function returns the first index >= "start" where "target" can be found
within "source".  Indices are 1-based.  If "target" is not found, then this
function returns 0.  If either "source" or "target" are missing / empty, this
function also returns 0.

This function should be safe for UTF-8 strings.
]]
function str.find( frame )
	local new_args = str._getParameters( frame.args, {'source', 'target', 'start', 'plain' } )
	local source_str = new_args['source'] or ''
	local pattern = new_args['target'] or ''
	local start_pos = tonumber(new_args['start']) or 1
	local plain = new_args['plain'] or true
		
	if source_str == '' or pattern == '' then
		return 0
	end
	
	plain = str._getBoolean( plain )

	local start = mw.ustring.find( source_str, pattern, start_pos, plain )
	if start == nil then
		start = 0
	end
	
	return start
end

--[[
replace

This function allows one to replace a target string or pattern within another
string.

Usage:
{{#invoke:String|replace|source_str|pattern_string|replace_string|replacement_count|plain_flag}}
OR
{{#invoke:String|replace|source=source_string|pattern=pattern_string|replace=replace_string|
   count=replacement_count|plain=plain_flag}}

Parameters
	source: The string to search
	pattern: The string or pattern to find within source
	replace: The replacement text
	count: The number of occurences to replace, defaults to all.
	plain: Boolean flag indicating that pattern should be understood as plain
		text and not as a Lua style regular expression, defaults to true
]]
function str.replace( frame )
	local new_args = str._getParameters( frame.args, {'source', 'pattern', 'replace', 'count', 'plain' } )
	local source_str = new_args['source'] or ''
	local pattern = new_args['pattern'] or ''
	local replace = new_args['replace'] or ''
	local count = tonumber( new_args['count'] )
	local plain = new_args['plain'] or true
	
	if source_str == '' or pattern == '' then
		return source_str
	end
	plain = str._getBoolean( plain )

	if plain then
		pattern = str._escapePattern( pattern )
		replace = mw.ustring.gsub( replace, "%%", "%%%%" ); --Only need to escape replacement sequences.
	end
	
	local result

	if count ~= nil then
		result = mw.ustring.gsub( source_str, pattern, replace, count )
	else
		result = mw.ustring.gsub( source_str, pattern, replace )
	end

	return result
end

--[[
simpletitle

This function returns the current page title without the homonymy part (the part in parenthesis).

Usage:
{{#invoke:String|simpletitle}}
OR
{{#invoke:String|simpletitle|string}}

Parameters
	string: if present this function will treat this string as the title of the page and remove
	   homonymy part if present in it. If not given the function uses the page title (without namespace)
]]
function str.simpletitle(frame)
	-- si un paramètre est indiqué, on l'utilise comme titre à traiter
	-- sinon on utilise le titre de la page actuelle
	local page = frame.args[1]
	if (page == nil or page == "") then
	  page = mw.title.getCurrentTitle().text
	end

	-- on enlève la partie entre parenthèses
	local npage = mw.ustring.gsub(page, " [(][^()]*[)]$", "")
	if (npage == nil or npage == "") then return "" end

	return npage
end


--[[
titledisambig

This function returns the part of the title used for disambiguation,
including the parenthesis themselves and the space just before.
 
Usage:
{{#invoke:String|titledisambig}}
OR
{{#invoke:String|titledisambig|string}}

Parameters
	string: if present this function will treat this string as the title of the page.
	If not given the function uses the page title.
]]
function str.titledisambig(frame)
	-- si un paramètre est indiqué, on l'utilise comme titre à traiter
	-- sinon on utilise le titre de la page actuelle
	local page = frame.args[1]
	if (page == nil or page == "") then
	  page = mw.title.getCurrentTitle().text
	end
 
	-- on retourne la partie entre parenthèses,
	-- en incluant les parenthèses et l'espace précédente
	local disambigStart = string.find(page, " %(")
	if disambigStart then
		return string.sub(page, disambigStart)
	else
		return ""
	end
end


--[[
trim

Cette fonction retourne son unique paramètre en supprimant les espaces
et sauts de ligne au début et à la fin (fonction "trim")

Usage :
{{#invoke:String|trim|string}}

Paramètres :
	la chaîne 'string' dont on veut supprimer les éventuels espaces
	et sauts de ligne au début et/ou à la fin
]]
function str.trim(frame)
	local txt = frame.args[1]
	if not txt or txt == "" then
		return ""
	end
	return mw.text.trim(txt)
end


--[[
rep

Cette fonction retourne la concaténation de son premier paramètre n fois où n est le deuxième paramètre (fonction "rep" ou "repeat")

Usage :
{{#invoke:String|rep|string|int}}

Paramètres :
	la chaîne 'string' dont on veut répeter
	l'entier 'int' le nombre d'itération
]]
function str.rep(frame)
	local new_args = str._getParameters( frame.args, { 's', 'n' } )
	local s = new_args['s'] or ''
	local n = tonumber( new_args['n'] ) or 1
	if not s or s == '' then
		return ''
	end
	if not n or n <0 then
		return s
	end
	return mw.ustring.rep(s,n)
end


--[[
Helper function that populates the argument list given that user may need to use a mix of
named and unnamed parameters.  This is relevant because named parameters are not
identical to unnamed parameters due to string trimming, and when dealing with strings
we sometimes want to either preserve or remove that whitespace depending on the application.
]]
function str._getParameters( frame_args, arg_list )
	local new_args = {}
	local index = 1
	
	for i = 1, #arg_list do
		local arg = arg_list[i]
		local value = frame_args[arg]
		if value == nil then
			value = frame_args[index]
			index = index + 1
		end
		new_args[arg] = value
	end
	
	return new_args
end

--[[
Helper function to handle error messages.
]]
function str._error( error_str )
	local frame = mw.getCurrentFrame()
	local error_category = frame.args.error_category or 'Errors reported by Module String'
	local ignore_errors = frame.args.ignore_errors or false
	local no_category = frame.args.no_category or false
	
	if str._getBoolean(ignore_errors) then
		return ''
	end
	
	local error_str = '<strong class="error">String Module Error: ' .. error_str .. '</strong>'
	if error_category ~= '' and not str._getBoolean( no_category ) then
		error_str = '[[Category:' .. error_category .. ']]' .. error_str
	end
	
	return error_str
end

--[[
Helper Function to interpret boolean strings
]]
function str._getBoolean( boolean_str )
	local boolean_value
	
	if type( boolean_str ) == 'string' then
		boolean_str = boolean_str:lower()
		if boolean_str == 'false' or boolean_str == 'no' or boolean_str == '0'
				or boolean_str == '' then
			boolean_value = false
		else
			boolean_value = true
		end
	elseif type( boolean_str ) == 'boolean' then
		boolean_value = boolean_str
	else
		error( 'No boolean value found' )
	end
	return boolean_value
end

--[[
Helper function that escapes all pattern characters so that they will be treated
as plain text.
]]
function str._escapePattern( pattern_str )
	return mw.ustring.gsub( pattern_str, "([%(%)%.%%%+%-%*%?%[%^%$%]])", "%%%1" )
end

--[[
count
This function counts the number of occurrences of one string in another.
]]
function str.count(frame)
	local args = str._getParameters(frame.args, {'source', 'pattern', 'plain'})
	local source = args.source or ''
	local pattern = args.pattern or ''
	local plain = str._getBoolean(args.plain or true)
	if plain then
		pattern = str._escapePattern(pattern)
	end
	local _, count = mw.ustring.gsub(source, pattern, '')
	return count
end

return str