Module:string

local m_string_utils = require("Module:string utilities")

local str = {}

local decode_uri = m_string_utils.decode_uri local gsub = string.gsub local pattern_escape = m_string_utils.pattern_escape local process_params = require("Module:parameters").process local replacement_escape = m_string_utils.replacement_escape local reverse = string.reverse local ufind = m_string_utils.find local ugmatch = m_string_utils.gmatch local ugsub = m_string_utils.gsub local ulen = m_string_utils.len local ulower = m_string_utils.lower local umatch = m_string_utils.match local unpack = unpack local usub = m_string_utils.sub

--[[ len

This function returns the length of the target string.

Usage:

OR

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) return ulen(str._getParameters(frame.args, {"s"}).s or "") end

--[[ len_visible

This function returns the length of the target string, excluding the text encompassed in < ... >

Usage: exactly as len, above. ]] function str.len_visible(frame) return ulen(ugsub(str._getParameters(frame.args, {"s"}).s or "", "<[^<>]+>", "")) end

--[[ sub

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

Usage:

OR

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 = ulen(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 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 usub(s, i, j) end

-- This function implements that features of 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 usub(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:

OR

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) > ulen(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 = pattern_escape(pattern); end local result if match_index == 1 then -- Find first match is simple case result = umatch(s, pattern, start) else if start > 1 then s = usub(s, start); end local iterator = ugmatch(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:

OR

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) > ulen(target_str) then return str._error('String index out of range'); end return usub(target_str, pos, pos); end

--[[ str_find

This function duplicates the behavior of, 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 = ufind(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:

OR

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 an empty string. If either "source" or "target" are missing / empty, this function also returns an empty string.

This function should be safe for UTF-8 strings. ]] function str.find(frame) local main_param = {required = true, allow_empty = true} return ufind(unpack(process_params(frame.args, {		[1] = main_param,		[2] = main_param,		[3] = {type = "number"},		[4] = {type = "boolean"},	}))) end

--[[ replace

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

Usage:

OR

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 = pattern_escape(pattern); replace = replacement_escape(replace); end local result; result = ugsub(source_str, pattern, replace, count); return result; end

function str.gsub(frame) local main_param = {required = true, allow_empty = true, allow_whitespace = true} return (ugsub(unpack(process_params(frame.args, { [1] = main_param, [2] = main_param, [3] = main_param, [4] = {type = "number"}, })))) 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('function rep expects a number as second parameter, received "' .. (frame.args[2] or '') .. '"') end return string.rep(frame.args[1] or '', repetitions) end

function str.lower(frame) return ulower(frame.args[1] or "") end str.lc = str.lower

--[[ format

This function allows one to format strings according to a template. This is a direct interface onto str.format in Lua, and works like the C printf function.

For example:

will produce the result page_0065.html

Parameters 1: The format template. See https://www.mediawiki.org/wiki/Extension:Scribunto/Lua_reference_manual#string.format 2, 3, ...: Arguments to be inserted into the template.

Note that leading and trailing whitespace is not removed from the arguments. ]] function str.format(frame) local fmt = frame.args[1] -- You can't call unpack directly on frame.args because it isn't really a	-- table, and doesn't support the # operator. local args = {} local i = 2 while true do		local val = frame.args[i] if not val then break end table.insert(args, val) i = i + 1 end return fmt:format(unpack(args)) 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; 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 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 = ' String Module Error: ' .. error_str .. ' ';	if error_category ~= '' and not str._getBoolean(no_category) then error_str = '' .. 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

function str.count(text, pattern, plain) if not (type(text) == "string" or type(text) == "number") then error('The first argument to the function "count" must be a string or a number, not a ' .. type(text) .. '.') end if not (type(pattern) == "string" or type(pattern) == "number") then error('The first argument to the function "count" must be a string or a number, not a ' .. type(text) .. '.') end if plain then pattern = pattern_escape(pattern) end local _, count = ugsub(text, pattern, "") return count end

function str.matchToArray(text, pattern) local invoked = false if type(text) == "table" then invoked = true if text.args then local frame = text local params = { [1] = { required = true }, [2] = { required = true }, }			local args = process_params(frame.args, params) text = args[1] pattern = args[2] else error("If the first argument to matchToArray is a table, it should be a frame object.") end else if not (type(pattern) == "string" or type(pattern) == "number") then error("The second argument to matchToArray should be a string or a number.") end end local matches = {} local i = 0 for match in ugmatch(text, pattern) do		i = i + 1 matches[i] = match end if i > 0 then if invoked then return table.concat(matches, ", ") else return matches end else if invoked then return "" else return nil end end end

--[=[	Similar to gmatch, but it returns the count of the match in addition to the list of captures, something like ipairs. If the pattern doesn't contain any captures, the whole match is returned. Invoke thus: for i, whole_match in require("Module:string").imatch(text, pattern) do			[ do something with i and whole_match ] end or for i, capture1[, capture2[, capture3[, ...]]] in require("Module:string").imatch(text, pattern) do			[ do something with i and capture1 ] end For example, this code for i, whole_match in require("Module:string").imatch("a b c", "[a-z]") do			mw.log(i, whole_match) end will log 1	a 2	b 3	c ]=] function str.imatch(text, pattern, pos, plain, use_basic_Lua_function) local i = 0 pos = pos or 0 if not string.find(pattern, "%b") then pattern = "(" .. pattern .. ")" end local find = use_basic_Lua_function and string.find or ufind return function i = i + 1 local return_values = { find(text, pattern, pos, plain) } local j = return_values[2] if return_values[3] then pos = j + 1 -- Skip the first two returned values, which are the indices of the -- whole match. return i, unpack(return_values, 3) end end end

function str.URIdecode(frame) return decode_uri(frame.args[1], frame.args[2] or "PATH") end

function str:__index(k) self[k] = package.loaders[2]("Module:string/" .. k) return self[k] end

return setmetatable(str, str)