--- Miscellaneous useful functions. local lib = {}  local util = require('libraryUtil') local checkType = util.checkType local checkTypeMulti = util.checkTypeMulti local NIL_OK = true  --- Choose one of two values to return. --  @param {boolean} cond Determines which value to return. --  @param T The value to return if `cond` is true (or truthy). --  @param F The value to return if `cond` is false (or falsey). function lib.ternary(cond, T, F)     if cond then         return T     end      return F end  --- Some functions from `mw.text` are slow or may not always work as intended. --  This group of functions provides better alternatives for them. --  @section `mw.text` replacements  ---  --  Removes ASCII whitespace from the start and end of `text`. --  Slightly more efficient than the `mw.text` implementation. --  @see https://help.fandom.com/wiki/Extension:Scribunto#mw.text.trim_is_slow --  @param {string} text The text to trim. --  @return {string} The trimmed text. function lib.trim(text) 	return (text:gsub( '^[\t\r\n\f ]+', '' ):gsub( '[\t\r\n\f ]+$', '' )) 	-- the "extra" parentheses are important for removing the second value returned from `gsub` end   --- Returns an iterator over substrings that would be returned by @{lib.split}. --  @see @{lib.split} for argument documentation. --  @return {function} Iterator over substrings of `text` separated by `delim`. function lib.gsplit(text, delim, opt) 	checkType('Feature.gsplit', 1, text, 'string') 	checkType('Feature.gsplit', 2, delim, 'string', NIL_OK) 	checkType('Feature.gsplit', 3, opt, 'table', NIL_OK) 	if delim == nil then delim = " " end 	if opt == nil then opt = {} end 	-- the mediawiki implementation uses ustring, which is slower than string 	-- and also not necessary if delim isn't a pattern. 	-- https://help.fandom.com/wiki/Extension:Scribunto#mw.text.split_is_very_slow 	 	-- local g = mw.text.gsplit(text, delim, true) 	-- local function f() 	-- 	local value = g() 	-- 	if value and not opt.noTrim then -- value is nil when the generator ends 	-- 		value = mw.text.trim(value) 	-- 	end 	-- 	if value == "" and opt.removeEmpty then 	-- 		return f() 	-- 	end 	-- 	return value 	-- end 	-- return f, nil, nil 	 	-- based on https://github.com/wikimedia/mediawiki-extensions-Scribunto/blob/1eecdac6def6418fb36829cc2f20b464c30e4b37/includes/Engines/LuaCommon/lualib/mw.text.lua#L222 	if delim==';' and text:find('(%&[#%d%w]+);') then 		text = text:gsub('(%&[#%d%w]+);', '%1‡'); 	end 	local s, l = 1, #text 	local function f() 		if s then 			local e, n = string.find( text, delim, s, true ) 			local ret 			if not e then 				ret = string.sub( text, s ) 				s = nil 			elseif n < e then 				-- Empty separator! 				ret = string.sub( text, s, e ) 				if e < l then 					s = e + 1 				else 					s = nil 				end 			else 				ret = e > s and string.sub( text, s, e - 1 ) or '' 				s = n + 1 			end 			 			if not opt.noTrim then 				ret = lib.trim(ret) 			end 			if ret == '' and opt.removeEmpty then 				return f() 			end 			if delim==';' and ret:find('(%&[#%d%w]+)‡') then 				ret = ret:gsub('(%&[#%d%w]+)‡', '%1;'); 			end 			return ret 		end 	end 	return f, nil, nil end  --- Returns a table containing the substrings of `text` that are separated by `delim`. --  (Compared to @{mw.text.split}, this function always treats `delim` as a literal --  string rather than a pattern, and it trims output substrings using @{lib.trim} by default.) --  @param       {string} text The string to split. --  @param[opt]  {string} delim The delimiter string to use when splitting `text`. --                 (Using an empty string will split `text` into individual characters.) --  @param[opt]  {table} opt Extra options: --  @param[opt]  {boolean} opt.noTrim Set true to disable trimming of generated substrings --                  using @{lib.trim}. --  @param[opt]  {boolean} opt.removeEmpty Set true to omit empty substrings --                  (i.e., when multiple `delim` appear consecutively, or when --                  `delim` appears at the start or end of `text`). --  @return {table} Substrings of `text separated by `delim`. function lib.split(text, delim, opt) 	checkType('Feature.split', 1, text, 'string') 	checkType('Feature.split', 2, delim, 'string', NIL_OK) 	checkType('Feature.split', 3, opt, 'table', NIL_OK) 	local output = {} 	for item in lib.gsplit(text, delim, opt) do 		table.insert(output, item) 	end 	return output end  --- A wrapper around @{mw.text.unstripNoWiki} that un-escapes --  characters/sequences that <nowiki> escapes. --  @see https://github.com/wikimedia/mediawiki/blob/c22d01f23b7fe754ef106e97bae32c3966f8db3e/includes/parser/CoreTagHooks.php#L146 --             for MediaWiki source code for <nowiki> function lib.unstripNoWiki(str) 	return (mw.text.unstripNoWiki(str) 		:gsub('&lt;', '<'):gsub('&gt;', '>') 		:gsub('-&#123;', '-{'):gsub('&#125;-', '}-')) 	-- the "extra" parentheses are important for removing the second value returned from `gsub` end  --- @section end  --- Returns an iterator over `tbl` that outputs items in the order defined by `order`. --  @param      {table} tbl The table to iterate over. --  @param[opt] {table|function} order The iteration order. --  --                Can be specified either as an ordered list (table) of keys from `tbl` --                or as an ordering function that accepts `tbl`, `keyA`, and `keyB` --                and returns true when the entry in `tbl` associated wity `keyA` --                should come before the one for `keyB`. -- --                If not specified, the keys' natural ordering is used --                (i.e., `function(tbl, a, b) return a < b end`). --  @return {function} The iterator. function lib.spairs(tbl, order) 	checkType('Feature.spairs', 1, tbl, 'table') 	checkTypeMulti('Feature.spairs', 2, order, {'table', 'function', 'nil'}) 	local keys 	if type(order) == "table" then 		keys = order 	else 	    -- collect the keys 		keys = {} 		for k in pairs(tbl) do table.insert(keys, k) end 		 		-- sort the keys (using order function if given) 		if order then 		    table.sort(keys, function(a, b) return order(tbl, a, b) end) 		else 		    table.sort(keys) 		end     end      -- return the iterator function 	local i = 0 	return function() 		i = i + 1 		local key = keys[i] 		return key, tbl[key] 	end end  --[[ 	Parses Phantom Template Format strings into a list of maps. 	@param       {string} input A string formed by concatenating the output of Phantom Templates. 		Usually, this string is generated by DPL. 	@param[opt]  {string} key_separator Separator between the entries (key-value pairs) of items in `input`. Defaults to ';'. 	@param[opt]  {string} end_separator Separator between items in `input`. Defaults to '$'. 	@param[opt]  {string} equal_separator Separator between the key and value of each entry in `input`. Defaults to '='. 	@return      {table} A list of items from `input`; each value is a map of the item's entries. --]] function lib.parseTemplateFormat (inputStr, key_separator, end_separator, equal_separator) 	if key_separator == nil then key_separator = ";" end 	if end_separator == nil then end_separator = "$" end 	if equal_separator == nil then equal_separator = "=" end 	 	local arg_format = "^%s*(.-)%s*" .. equal_separator .. "%s*(.-)%s*$" 	 	local resultTable = {} 	for str in lib.gsplit(inputStr, end_separator, {noTrim=true, removeEmpty=true}) do 		local result = {} 		for param in lib.gsplit(str, key_separator) do 			local arg, val = param:match(arg_format) 			if arg then 				result[arg] = val 			else 				-- skip, i guess 				-- mw.log("Warning: Lua module found extra " .. key_separator .. " or " .. end_separator .. " separators in DPL output.") 			end 		end 		table.insert(resultTable, result) 	end 	return resultTable end  --[=[ 	Parses Phantom Template Format strings into a list of ordered maps. 	@param       {string} input A string formed by concatenating the output of Phantom Templates. 		Usually, this string is generated by DPL. 	@param[opt]  {string} key_separator Separator between the entries (key-value pairs) of items in `input`. Defaults to ';'. 	@param[opt]  {string} end_separator Separator between items in `input`. Defaults to '$'. 	@param[opt]  {string} equal_separator Separator between the key and value of each entry in `input`. Defaults to '='. 	@return[name=output] {table} A list of items from `input`; each value is a list of the item's entries. 	@return[name=output[i]] {table} The i-th item of `input`. 	@return[name=output[i].page] {string} The value of the `page` key for this item. 	@return[name=output[i][j]] {table} The j-th key-value pair of this item. 	@return[name=output[i][j].key] {string} The j-th key of this item. 	@return[name=output[i][j].value] The j-th value of this item. --]=] function lib.parseTemplateFormatOrdered (inputStr, key_separator, end_separator, equal_separator) 	if key_separator == nil then key_separator = ";" end 	if end_separator == nil then end_separator = "$" end 	if equal_separator == nil then equal_separator = "=" end 	 	local arg_format = "^%s*(.-)%s*" .. equal_separator .. "%s*(.-)%s*$" 		 	local resultTable = {} 	for str in lib.gsplit(inputStr, end_separator, {noTrim=true, removeEmpty=true}) do 		local result = {} 		for param in lib.gsplit(str, key_separator) do 			local arg, val = param:match(arg_format) 			if arg == 'page' then 				result['page'] = val 			else 				table.insert(result,{ 					key = arg, 					value = val 				}) 			end 		end 		table.insert(resultTable, result) 	end 	return resultTable end  -- searches ordered table and returns value function lib.orderedTableSearch(tbl, search)     for i, obj in ipairs(tbl) do         if obj.key == search then             return obj.value         end     end     return false end  --- Add thousands separator to number `n`. --  @param {number|frame} n If a frame is given, then its first argument (`frame.args[1]`) will be used as input instead. --  @return {string} The number formatted with commas for thousands separators. --  @see https://stackoverflow.com/questions/10989788/format-integer-in-lua/10992898#10992898 function lib.thousandsSeparator(n) 	if (n == mw.getCurrentFrame()) then 		n = n.args[1] 	elseif (type(n) == "table") then 		n = n[1] 	end 	 	local i, j, minus, int, fraction = tostring(n):find('([-]?)(%d+)([.]?%d*)')  	-- reverse the int-string and append a comma to all blocks of 3 digits 	int = int:reverse():gsub("(%d%d%d)", "%1,") 	 	-- reverse the int-string back remove an optional comma and put the optional minus and fractional part back 	return minus .. int:reverse():gsub("^,", "") .. fraction end   --- @return {boolean} true iff string or table is empty --  @note May not be correct for tables with metatables. function lib.isEmpty(item) 	if item == nil or item == "" then 		return true 	end 	if type(item) == "table" then 		return next(item) == nil 	end 	return false end  --- @return {boolean} true iff string or table is not empty --  @note May not be correct for tables with metatables. function lib.isNotEmpty(item) 	return not lib.isEmpty(item) end  --- @return nil if string or table is empty, otherwise return the value. function lib.nilIfEmpty(item) 	if lib.isEmpty(item) then 		return nil 	else 		return item 	end end  --- -- @param {table} t A table of items -- @param elm The item to search for -- @returns true if `elm` is a value in `t`; false otherwise. (Does not check keys of `t`.) -- @see http://stackoverflow.com/q/2282444 -- @see another implementation: Dev:TableTools.includes() function lib.inArray(t, elm)     for _, v in pairs(t) do         if v == elm then             return true         end     end     return false end  return lib