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Mòdul:String

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M�dul String (codi  �s  discussi�  proves  tests  casos prova | subp�gines  enlla�os)

A continuaci� es mostra la documentaci� transclosa de la subp�gina /�s. [salta a la caixa de codi]


Aquest m�dul proporciona acc�s a funcions b�siques sobre cadenes (strings).

La majoria d'aquestes funcions es poden invocar amb par�metres amb nom, sense nom o una barreja. Si s'usen par�metres amb nom cal tenir en compte que el Mediawiki elimina els espais en blanc inicials i finals del valor del par�metre. Segons l'�s previst pot ser convenient tant conservar-los com eliminar-los.

Algunes funciones admeten par�metres amb patrons Lua que s�n una mena d'expressions regulars. Vegeu en el manual: patterns i Ustring patterns.

Opcions globals:

  • ignore_errors: posat a 'true' o 1, en cas d'error retorn una cadena buida en lloc del missatge d'error.
  • error_category: si es detecta un error especifica el nom de la categoria a incloure amb el missatge d'error. Per defecte �s Categoria:Errors detectats pel m�dul String.
  • no_category: posat a 'true' o 1, no afegeix cap categoria si es genera un error.

Funcions

len

Retorna la longitud de la cadena. >>> Es pot cridar amb {{Str len}}.

Sintaxi
{{#invoke:string|len|cadena}}
{{#invoke:string|len|s=cadena}}

Par�metres:

s: La cadena a trobar la seva longitud

sub

Retorna una subcadena de la cadena indicada en els �ndex especificats. >>> Es pot cridar amb {{Str sub}}.

Sintaxi
{{#invoke:string|sub|cadena|�ndex inicial|�ndex final}}
{{#invoke:string|sub|s=cadena|i=�ndex inicial|j=�ndex final}}

Par�metres:

s: la cadena on extraure la subcadena
i: �ndex inicial de la subcadena, per defecte 1, el primer car�cter de la cadena.
j: �ndex final de la subcadena, per defecte la longitud total, fins l'�ltim car�cter.

Si qualsevol dels dos �ndexs tenen valor negatiu llavors comptar� des del final de la cadena. Aix�, -1 �s l'�ndex de l'�ltim car�cter de la cadena. Si els �ndexs s�n superiors a la longitud de la cadena llavors reportar� un error.

match

Retorna una subcadena de la cadena indicada que coincideixi amb un patr� especificat.

Sintaxi
{{#invoke:string|match|cadena|patr�|�ndex inicial|n�mero coincid�ncia|indicador text net|text no coincid�ncia}}
{{#invoke:string|match|s=cadena|pattern=patr�|start=�ndex inicial|match=n�mero coincid�ncia|plain=indicador text net|nomatch=text no coincid�ncia}}

Par�metres:

s: cadena on es fa la cerca
pattern: patr� o cadena a cercar.
start: �ndex de la cadena on comen�ar a cercar, per defecte 1, el primer car�cter.
match: si es troben m�ltiples coincid�ncies, especifica quina d'elles retornar. Per defecte �s 1, la primera coincid�ncia trobada. Un n�mero negatiu compta des del final, per tant match=-1 �s l'�ltima coincid�ncia.
plain: indica si el patr� s'ha d'interpretar com a text net, per defecte 'false'.
nomatch: en cas de no trobar cap coincid�ncia, retorna el valor de "nomatch" en lloc d'un error.

Si el n�mero match o l'�ndex start estan fora del rang de la cadena, llavors la funci� genera un error. Tamb� genera un error si no troba cap coincid�ncia. Amb el par�metre global ignore_errors=true se suprimeix l'error i retorna una cadena buida.

pos

Retorna el car�cter de la cadena que es troba en la posici� indicada.

Sintaxi
{{#invoke:string|pos|cadena|�ndex}}
{{#invoke:string|pos|target=cadena|pos=�ndex}}

Par�metres:

target: cadena on cercar
pos: �ndex del car�cter a retornar

El primer car�cter t� l'�ndex 1. L'�ltim �s -1, comptant des del final. Si et� fora del rang de la cadena llavors retornar� un error.

find

Retorna la posici� on es troba una cadena o patr� cercant en una altra cadena. >>> Es pot cridar amb {{Str find}}.

Sintaxi
{{#invoke:string|find|cadena|cerca|�ndex inicial|indicador text net}}
{{#invoke:string|find|source=cadena|target=cerca|start=�ndex inicial|plain=indicador text net}}

Par�metres:

source: cadena on cercar
target: cadena a cercar o patr� de cerca
start: �ndex de la cadena font on comen�ar a cercar, per defecte 1, el primer car�cter.
plain: indica si la cerca s'ha d'interpretar com a text net, en cas contrari com a patr� Lua. Per defecte �s 'true'.

Retorna el primer �ndex, major o igual que "start", on "target" s'ha trobat a "source". Si no el troba retorna 0. Si "source" o "target" estan buits o indefinits tamb� retorna 0. Se suposa que funciona b� amb cadenes UTF-8.

replace

Permet reempla�ar una cadena o patr� en una altra cadena. >>> Es pot cridar amb {{Str rep}}.

Sintaxi
{{#invoke:string|replace|cadena|patr�|reempla�ament|comptador|indicador text net}}
{{#invoke:string|replace|source=cadena|pattern=patr�|replace=reempla�ament|count=comptador|plain=indicador text net}}

Par�metres:

source: cadena on cercar
pattern: cadena de cerca o patr� a cercar
replace: text de reempla�ament
count: n�mero d'ocurr�ncies a reempla�ar, per defecte totes.
plain: indica si la cerca s'ha d'interpretar com a text net, en cas contrari com a patr� Lua. Per defecte �s 'true'.

rep

Repeteix la cadena un n�mero de vegades.

{{#invoke:string|rep|cadena|vegades}}

Par�metres:

cadena: cadena a repetir
vegades: n�mero de vegades a repetir

strip

Suprimeix car�cters de la cadena. >>> Es pot cridar amb {{Str strip}}.

Sintaxi
{{#invoke:String|strip|cadena|car�cters|text_pla}}
{{#invoke:String|strip|source=cadena|chars=car�cters|plain=text_pla}}

Par�metres:

source: La cadena a tractar
chars: El patr� o llista de car�cters a suprimir de la cadena
plain: Indicador sobre si el par�metre chars ha de ser ent�s com a text pla (si �s true) o si ha de ser ent�s com a expressi� regular de tipus Lua (si �s false). Per defecte �s true.

Els espais en blanc del principi i el final tamb� se suprimeixen de la cadena.

split

Trosseja una cadena segons un separador, i retorna el tros n-�ssim, segons l'�ndex donat. >>> Es pot cridar amb {{Str split}}.

Sintaxi
{{#invoke:String|split|cadena|separador|�ndex}}
{{#invoke:String|split|source=cadena|separator=separador|count=�ndex}}

Par�metres:

source: La cadena a tractar
separator: El separador pel qual s'ha de trossejar la cadena
count: L'�ndex del tros a retornar

isNumber

Estableix si la cadena �s un nombre. >>> Es pot cridar amb {{Str IsNumber}}.

Sintaxi
{{#invoke:String|isNumber|cadena}}
{{#invoke:String|isNumber|source=cadena}}

Par�metres:

source: La cadena a tractar

count

{#invoke:String|count|aabbcc|a}}: 2 --nombre de a
{#invoke:String|count|aabbcc|z}} :0 --nombre de z
{#invoke:String|count|aabbcc|[ac]|plain=false}} : 4 --nombre de a ou de c
{#invoke:String|count|11-aa-2587|[0-9]|plain=false}} : 6 --nombre de chiffres
{#invoke:String|count|Il �tait une fois| |plain=true}} : 3 --nombre de blancs
{#invoke:String|count|Il �tait une fois|[ ]|plain=false}} : 3 --nombre de blancs

--[[

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 p = {}

--[[
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.
]]
local function _getParameters( frame_args, arg_list )
	local new_args = {}
	local index = 1
	local value
	
	for _, arg in ipairs( arg_list ) do
		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 interpret boolean strings
]]
local function _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( 'Cap valor boole� trobat' )
	end
	return boolean_value
end

--[[
Helper function to handle error messages.
]]
local function _error( error_str )
	local frame = mw.getCurrentFrame()
	local error_category = frame.args.error_category or 'Errors detectats pel m�dul String'
	local ignore_errors = frame.args.ignore_errors or false
	local no_category = frame.args.no_category or false
	
	if _getBoolean(ignore_errors) then
		return ''
	end
	
	local error_str = '<strong class="error">Error del m�dul String: ' .. error_str .. '</strong>'
	if error_category ~= '' and not _getBoolean( no_category ) then
		error_str = '[[Categoria:' .. error_category .. ']]' .. error_str
	end
	
	return error_str
end

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

--[[
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 p.len( frame )
	local new_args = _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 p.sub( frame )
	local new_args = _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 _error( '�ndex fora del rang de la cadena' )
	end
	if j < i then
		return _error( '�ndexs de la cadena no ordenats' )
	end
	
	return mw.ustring.sub( s, i, j )
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|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: 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

]]
-- This sub-routine is exported for use in other modules
function p._match( s, pattern, start, match_index, plain_flag, nomatch )
	if s == '' then
		return _error( 'Cadena on cercar est� buida' )
	end
	if pattern == '' then
		return _error( 'Cadena de cerca est� buida' )
	end
	start = tonumber(start) or 1
	if math.abs(start) < 1 or math.abs(start) > mw.ustring.len( s ) then
		return _error( '�ndex d\'inici fora del rang de la cadena' )
	end
	if match_index == 0 then
		return _error( 'N�mero de coincid�ncia fora de rang' )
	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 _error( 'Cap coincid�ncia trobada' )
		else
			return nomatch
		end
	else
		return result
	end
end
-- This is the entry point for #invoke:String|match
function p.match( frame )
	local new_args = _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 = _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']
	
	return p._match( s, pattern, start, match_index, plain_flag, nomatch )
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 p.pos( frame )
	local new_args = _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 _error( '�ndex fora del rang de la cadena' )
	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 p.find( frame )
	local new_args = _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 = _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 p.replace( frame )
	local new_args = _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 = _getBoolean( plain )
	
	if plain then
		pattern = _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

--[[
    simple function to pipe string.rep to templates.
]]
function p.rep( frame )
	local repetitions = tonumber( frame.args[2] )
	if not repetitions then 
		return _error( "s'esperava un n�mero com a segon par�metre; trobat: " .. ( frame.args[2] or '' ))
	end
	return string.rep( frame.args[1] or '', repetitions )
end

--[[
escapePattern

This function escapes special characters from a Lua string pattern. See [1]
for details on how patterns work.

[1] https://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#Patterns

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

Parameters
    pattern_string: The pattern string to escape.
]]
function p.escapePattern( frame )
	local pattern_str = frame.args[1]
	if not pattern_str then
		return _error( 'No pattern string specified' )
	end
	local result = _escapePattern( pattern_str )
	return result
end

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

--[[
endswith
This function determines whether a string ends with another string.
]]
function p.endswith(frame)
	local args = _getParameters(frame.args, {'source', 'pattern'})
	local source = args.source or ''
	local pattern = args.pattern or ''
	if pattern == '' then
		-- All strings end with the empty string.
		return "yes"
	end
	if mw.ustring.sub(source, -mw.ustring.len(pattern), -1) == pattern then
		return "yes"
	else
		return ""
	end
end

--[[
join

Join all non empty arguments together; the first argument is the separator.
Usage:
{{#invoke:String|join|sep|one|two|three}}
]]
function p.join(frame)
	local args = {}
	local sep
	for _, v in ipairs( frame.args ) do
		if sep then
			if v ~= '' then
				table.insert(args, v)
			end
		else
			sep = v
		end
	end
	return table.concat( args, sep or '' )
end

--[[ 
Strip

This function Strips charecters from string

Usage:
{{#invoke:StringFunc|strip|source_string|charecters_to_strip|plain_flag}}

Parameters
	source: The string to strip
	chars:  The pattern or list of charecters to strip from string, replaced with ''
	plain:  A flag indicating that the chars should be understood as plain text. defaults to true.

Leading and trailing whitespace is also automatically stripped from the string. 
]]
function p.strip( frame )
	local new_args = _getParameters( frame.args,  {'source', 'chars', 'plain'} )
	local source_str = new_args['source'] or ''
	local chars = new_args['chars'] or ''
	source_str = mw.text.trim(source_str)
	if source_str == '' or chars == '' then 
		return source_str
	end
	local l_plain = _getBoolean( new_args['plain'] or true )
	if l_plain then
		chars = _escapePattern( chars )
	end
	local result
	result = mw.ustring.gsub(source_str, "["..chars.."]", '')
	return result
end

--[[
Split

This function Splits a string based on a separator, returns nth substring based on count.

Usage:
{{#invoke:StringFunc|split|source_string|separator|count}}

Parameters:
	source:    The string to return a subset of
	separator: The string to split on 
	count:     The nth substring based on the separator to return
]]
function p.split( frame )
	local new_args = _getParameters( frame.args, {'source', 'separator', 'count'} )
	local source_str = new_args['source'] or ''
	local separator = (new_args['separator'] or ''):gsub('"', '')
	local separator_len = mw.ustring.len(separator)
	if source_str == '' or separator == '' then
		return source_str;
	end
	local ret_count = tonumber( new_args['count'] ) or 1
	if ret_count < 1 then
		return ""
	end
	local start = 1
	local iter = mw.ustring.find(source_str, separator, start, true)
	if iter == nil then
		if ret_count == 1 then
			return source_str
		else
			return ""
		end
	else
		iter = iter - 1
	end
	if ret_count == 1 then
		return mw.ustring.sub( source_str, start, iter)
	end
    for i=2, ret_count do
    	start = iter+separator_len + 1
    	iter = mw.ustring.find(source_str, separator, start, true)
    	if iter == nil then
    		if ret_count == i then
    			return mw.ustring.sub(source_str, start, mw.ustring.len(source_str))
    		else
    			return ""
    		end
    	else
    		iter = iter - 1
    	end
    end
    return mw.ustring.sub( source_str,start,iter)
end

function p.isNumber( frame )
	local new_args = _getParameters( frame.args, {'source'} )
	local source_str = new_args['source'] or ''
	if source_str == '' then
	   return "false"
	end
	if tonumber(source_str) == nil and tonumber(string.gsub(source_str, ",", ".", 1) .. '') == nil then
		return "false"
	end
	return "true"
end

return p