string

--[[  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 booleà 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 mòdul 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 = 'Error del mòdul String: ' .. error_str .. '' 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( 'Índex fora del rang de la cadena' ) end if j < i then return _error( 'Índexs 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 està buida' ) end if pattern == '' then return _error( 'Cadena de cerca està buida' ) end start = tonumber(start) or 1 if math.abs(start) < 1 or math.abs(start) > mw.ustring.len( s ) then return _error( 'Índex d\'inici fora del rang de la cadena' ) end if match_index == 0 then return _error( 'Número de coincidència 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 coincidència 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( 'Índex 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 número com a segon paràmetre; 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