Módulo:String

En Galifontes, o Wikisource en galego.
Indicacións de uso do módulo

Aínda non se redactaron as instrucións sobre como usar este módulo.
Engadir a explicación sobre o seu uso.

Os editores poden probar cambios no mesmo en Módulo:String/probas.
Por favor, engade as categorías na subpáxina de documentación e os interwikis no Wikidata. Ver as subpáxinas deste módulo.
--[[

Este módulo fornece acceso básico a funcións de cadeas de caracteres

A maioría das funcións fornecidas poden invocarse con parámetros con nome,
sen nome ou mixtos. Cando se usen parámetros con nome o sistema Mediawiki
eliminará automáticamente calquera espazo en branco previo ou posterior no parámetro.

Opcións globais
	ignore_errors: Co valor 'true' ou 1 detecta calquera erro e da como resultado
		unha cadea baleira.
		
	error_category: Especifica o nome da categoría na que se inclúe
		o artigo que contén o erro. A categoría por defecto é
		[Categoría:Wikipedia:Erros no módulo string]
		
	no_category: Co valor 'true' ou 1 non engade ningunha categoría de erro.
		
]]

local str = {}

--[[
len

Lonxitude da cadea

Uso:
{{#invoke:String|len|cadea|}}
OU
{{#invoke:String|len|s=cadea}}

Parametros
	s: A cadea a encontrar a súa lonxitude 

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

Retorna unha sub-cadea entre os índices especificados

Usage:
{{#invoke:String|sub|cadea|índice_comezo|índice_final}}
OR
{{#invoke:String|sub|s=cadea|i=índice_comezo|j=índice_final}}

Parámetros
	s: A cadea onde extraer a subcadena 
	i: A cadea onde extraer a subcadena.
	j: Índice final da subcadena, por defecto a lonxitude total, ata o último carácter.
	
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 )
	
	-- Convertir negativos para la comprobación de rango
	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( 'Índice fóra do rango da cadea' )
	end
	if j < i then
		return str._error( 'Conxunto de índices da cadea fóra de orde' )
	end

	return mw.ustring.sub( s, i, j )
end

--[[
Función auxiliar para modelos máis antigos
								  
]]
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

Devolve unha subcadea da cadea fonte que cumpre un padrón determinado.

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

Parámetros
	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 str._match( s, pattern, start, match_index, plain_flag, nomatch )
	if s == '' then
		return str._error( 'A cadea obxectivo está baleira' )
	end
	if pattern == '' then
		return str._error( 'A cadea de padrón está baleira' )
	end
	start = tonumber(start) or 1
	if math.abs(start) < 1 or math.abs(start) > mw.ustring.len( s ) then
		return str._error( 'O punto de inicio solicitado está fóra de rango' )
	end
	if match_index == 0 then
		return str._error( 'O índice de coincidencia está fóra de rango' )
	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( 'Ningunha coincidencia atopada' )
		else
			return nomatch
		end
	else
		return result
	end
end
-- This is the entry point for #invoke:String|match
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']

	return str._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 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
	 
--[[
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
separatetly.
]]
function str.str_find( frame )
	local new_args = str._getParameters( frame.args, {'source', 'target'} )
	local source_str = new_args['source'] or ''
	local target_str = new_args['target'] or ''

	if target_str == '' then
		return 1
	end

	local start = mw.ustring.find( source_str, target_str, 1, true )
	if start == nil then
		start = -1
	end

	return start
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

--[[
	simple function to pipe string.rep to templates.
]]
function str.rep( frame )
	local repetitions = tonumber( frame.args[2] )
	if not repetitions then
		return str._error( 'A función rep espera un número para o segundo parámetro, obtivo "' .. ( 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 str.escapePattern( frame )
	local pattern_str = frame.args[1]
	if not pattern_str then
		return str._error( 'Non se especificou o padrón' )
	end
	local result = str._escapePattern( pattern_str )
		 
	return result
	   
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

--[[
endswith
This function determines whether a string ends with another string.
]]
function str.endswith(frame)
	local args = str._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 str.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

--[[
Función de axuda que enche a lista de argumentos, 
para que o usuario poida utilizar unha combinación de	parámetros con nome e sen nombre. 
Isto é importante porque os parámetros con nome non funcionan igual que os parámetros sen nome cando se encadenan recortes, 
e cuando se trata de cadeas ás veces débese conservar ou quitar espazos en branco dependendo da aplicación. 
]]
function str._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

--[[
Función de axuda para controlar as mensaxes de error.
]]
function str._error( error_str )
	local frame = mw.getCurrentFrame()
	local error_category = frame.args.error_category or 'Erros no módulo 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">Erro do módulo String: ' .. error_str .. '</strong>'
	if error_category ~= '' and not str._getBoolean( no_category ) then
		error_str = '[[Categoría:Wikipedia:' .. 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 == 'non' 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( 'Non se atopou valor booleano' )
	end
	return boolean_value
end

--[[
Función de axuda que escapa a todos os caracteres de patrón para que puedan ser tratados
como texto sen formato.
]]
function str._escapePattern( pattern_str )
	return mw.ustring.gsub( pattern_str, "([%(%)%.%%%+%-%*%?%[%^%$%]])", "%%%1" )
   
end

--[[ 
   -- Convirte en maiúsculas a primeira letra que aparece na edición dunha cadea
]] 

function str.mayuscula(frame) 
	local s = frame.args[1] or '';
	if s  ~= '' then		
		local cambio = {};
		local modo = {};
		if string.find(s, '|') ~= nil then -- Ligazóns con etiqueta
			modo = string.upper(string.match(s,'(|%a)'));
			cambio = string.gsub(s,'|%a', modo,1);
		elseif string.find(s, '[[]') ~= nil then -- Ligazóns sen etiqueta
			modo = string.upper(string.match(s,'^(..%a)'));
			cambio = string.gsub(s,'^..%a', modo,1);
		elseif string.match(s,'^%a') ~= nil then -- Sen ligazón
		   modo = string.upper(string.match(s,'^(%a)'));
		   cambio = string.gsub(s,'^%a', modo, 1);
		else
		   cambio = s;
		end
	
		return cambio;
	end
end

return str