--[[ ------------------------------------------------------------------------------------ --                               TableTools                                       -- --                                                                                -- -- This module includes a number of functions for dealing with Lua tables.        -- -- It is a meta-module, meant to be called from other Lua modules, and should     -- -- not be called directly from #invoke.                                           -- ------------------------------------------------------------------------------------ --]]  local libraryUtil = require('libraryUtil')  local p = {}  -- Define often-used variables and functions. local floor = math.floor local infinity = math.huge local checkType = libraryUtil.checkType local checkTypeMulti = libraryUtil.checkTypeMulti  --[[ ------------------------------------------------------------------------------------ -- isPositiveInteger -- -- This function returns true if the given value is a positive integer, and false -- if not. Although it doesn't operate on tables, it is included here as it is -- useful for determining whether a given table key is in the array part or the -- hash part of a table. ------------------------------------------------------------------------------------ --]] function p.isPositiveInteger(v) 	if type(v) == 'number' and v >= 1 and floor(v) == v and v < infinity then 		return true 	else 		return false 	end end  --[[ ------------------------------------------------------------------------------------ -- isNan -- -- This function returns true if the given number is a NaN value, and false -- if not. Although it doesn't operate on tables, it is included here as it is -- useful for determining whether a value can be a valid table key. Lua will -- generate an error if a NaN is used as a table key. ------------------------------------------------------------------------------------ --]] function p.isNan(v) 	if type(v) == 'number' and tostring(v) == '-nan' then 		return true 	else 		return false 	end end  --[[ ------------------------------------------------------------------------------------ -- shallowClone -- -- This returns a clone of a table. The value returned is a new table, but all -- subtables and functions are shared. Metamethods are respected, but the returned -- table will have no metatable of its own. ------------------------------------------------------------------------------------ --]] function p.shallowClone(t) 	local ret = {} 	for k, v in pairs(t) do 		ret[k] = v 	end 	return ret end  --[[ ------------------------------------------------------------------------------------ -- removeDuplicates -- -- This removes duplicate values from an array. Non-positive-integer keys are -- ignored. The earliest value is kept, and all subsequent duplicate values are -- removed, but otherwise the array order is unchanged. ------------------------------------------------------------------------------------ --]] function p.removeDuplicates(t) 	checkType('removeDuplicates', 1, t, 'table') 	local isNan = p.isNan 	local ret, exists = {}, {} 	for i, v in ipairs(t) do 		if isNan(v) then 			-- NaNs can't be table keys, and they are also unique, so we don't need to check existence. 			ret[#ret + 1] = v 		else 			if not exists[v] then 				ret[#ret + 1] = v 				exists[v] = true 			end 		end	 	end 	return ret end			  --[[ ------------------------------------------------------------------------------------ -- numKeys -- -- This takes a table and returns an array containing the numbers of any numerical -- keys that have non-nil values, sorted in numerical order. ------------------------------------------------------------------------------------ --]] function p.numKeys(t) 	checkType('numKeys', 1, t, 'table') 	local isPositiveInteger = p.isPositiveInteger 	local nums = {} 	for k, v in pairs(t) do 		if isPositiveInteger(k) then 			nums[#nums + 1] = k 		end 	end 	table.sort(nums) 	return nums end  --[[ ------------------------------------------------------------------------------------ -- affixNums -- -- This takes a table and returns an array containing the numbers of keys with the -- specified prefix and suffix. For example, for the table -- {a1 = 'foo', a3 = 'bar', a6 = 'baz'} and the prefix "a", affixNums will -- return {1, 3, 6}. ------------------------------------------------------------------------------------ --]] function p.affixNums(t, prefix, suffix) 	checkType('affixNums', 1, t, 'table') 	checkType('affixNums', 2, prefix, 'string', true) 	checkType('affixNums', 3, suffix, 'string', true)  	local function cleanPattern(s) 		-- Cleans a pattern so that the magic characters ()%.[]*+-?^$ are interpreted literally. 		s = s:gsub('([%(%)%%%.%[%]%*%+%-%?%^%$])', '%%%1') 		return s 	end  	prefix = prefix or '' 	suffix = suffix or '' 	prefix = cleanPattern(prefix) 	suffix = cleanPattern(suffix) 	local pattern = '^' .. prefix .. '([1-9]%d*)' .. suffix .. '$'  	local nums = {} 	for k, v in pairs(t) do 		if type(k) == 'string' then			 			local num = mw.ustring.match(k, pattern) 			if num then 				nums[#nums + 1] = tonumber(num) 			end 		end 	end 	table.sort(nums) 	return nums end  --[[ ------------------------------------------------------------------------------------ -- numData -- -- Given a table with keys like ("foo1", "bar1", "foo2", "baz2"), returns a table -- of subtables in the format  -- { [1] = {foo = 'text', bar = 'text'}, [2] = {foo = 'text', baz = 'text'} } -- Keys that don't end with an integer are stored in a subtable named "other". -- The compress option compresses the table so that it can be iterated over with -- ipairs. ------------------------------------------------------------------------------------ --]] function p.numData(t, compress) 	checkType('numData', 1, t, 'table') 	checkType('numData', 2, compress, 'boolean', true) 	local ret = {} 	for k, v in pairs(t) do 		local prefix, num = mw.ustring.match(tostring(k), '^([^0-9]*)([1-9][0-9]*)$') 		if num then 			num = tonumber(num) 			local subtable = ret[num] or {} 			if prefix == '' then 				-- Positional parameters match the blank string; put them at the start of the subtable instead. 				prefix = 1 			end 			subtable[prefix] = v 			ret[num] = subtable 		else 			local subtable = ret.other or {} 			subtable[k] = v 			ret.other = subtable 		end 	end 	if compress then 		local other = ret.other 		ret = p.compressSparseArray(ret) 		ret.other = other 	end 	return ret end  --[[ ------------------------------------------------------------------------------------ -- compressSparseArray -- -- This takes an array with one or more nil values, and removes the nil values -- while preserving the order, so that the array can be safely traversed with -- ipairs. ------------------------------------------------------------------------------------ --]] function p.compressSparseArray(t) 	checkType('compressSparseArray', 1, t, 'table') 	local ret = {} 	local nums = p.numKeys(t) 	for _, num in ipairs(nums) do 		ret[#ret + 1] = t[num] 	end 	return ret end  --[[ ------------------------------------------------------------------------------------ -- sparseIpairs -- -- This is an iterator for sparse arrays. It can be used like ipairs, but can -- handle nil values. ------------------------------------------------------------------------------------ --]] function p.sparseIpairs(t) 	checkType('sparseIpairs', 1, t, 'table') 	local nums = p.numKeys(t) 	local i = 0 	local lim = #nums 	return function () 		i = i + 1 		if i <= lim then 			local key = nums[i] 			return key, t[key] 		else 			return nil, nil 		end 	end end  --[[ ------------------------------------------------------------------------------------ -- size -- -- This returns the size of a key/value pair table. It will also work on arrays, -- but for arrays it is more efficient to use the # operator. ------------------------------------------------------------------------------------ --]]  function p.size(t) 	checkType('size', 1, t, 'table') 	local i = 0 	for k in pairs(t) do 		i = i + 1 	end 	return i end   local function defaultKeySort(item1, item2) 	-- "number" < "string", so numbers will be sorted before strings. 	local type1, type2 = type(item1), type(item2) 	if type1 ~= type2 then 		return type1 < type2 	else -- This will fail with table, boolean, function. 		return item1 < item2 	end end  --[[ 	Returns a list of the keys in a table, sorted using either a default 	comparison function or a custom keySort function. ]] function p.keysToList(t, keySort, checked) 	if not checked then 		checkType('keysToList', 1, t, 'table') 		checkTypeMulti('keysToList', 2, keySort, { 'function', 'boolean', 'nil' }) 	end 	 	local list = {} 	local index = 1 	for key, value in pairs(t) do 		list[index] = key 		index = index + 1 	end 	 	if keySort ~= false then 		keySort = type(keySort) == 'function' and keySort or defaultKeySort 		 		table.sort(list, keySort) 	end 	 	return list end  --[[ 	Iterates through a table, with the keys sorted using the keysToList function. 	If there are only numerical keys, sparseIpairs is probably more efficient. ]] function p.sortedPairs(t, keySort) 	checkType('sortedPairs', 1, t, 'table') 	checkType('sortedPairs', 2, keySort, 'function', true) 	 	local list = p.keysToList(t, keySort, true) 	 	local i = 0 	return function() 		i = i + 1 		local key = list[i] 		if key ~= nil then 			return key, t[key] 		else 			return nil, nil 		end 	end end  --[[ 	Returns true if all keys in the table are consecutive integers starting at 1. --]] function p.isArray(t) 	checkType("isArray", 1, t, "table") 	 	local i = 0 	for k, v in pairs(t) do 		i = i + 1 		if t[i] == nil then 			return false 		end 	end 	return true end  -- { "a", "b", "c" } -> { a = 1, b = 2, c = 3 } function p.invert(array) 	checkType("invert", 1, array, "table") 	 	local map = {} 	for i, v in ipairs(array) do 		map[v] = i 	end 	 	return map end  --[[ 	{ "a", "b", "c" } -> { ["a"] = true, ["b"] = true, ["c"] = true } --]] function p.listToSet(t) 	checkType("listToSet", 1, t, "table") 	 	local set = {} 	for _, item in ipairs(t) do 		set[item] = true 	end 	 	return set end  --[[ 	Recursive deep copy function. 	Preserves identities of subtables. 	 ]] local function _deepCopy(orig, includeMetatable, already_seen) 	-- Stores copies of tables indexed by the original table. 	already_seen = already_seen or {} 	 	local copy = already_seen[orig] 	if copy ~= nil then 		return copy 	end 	 	if type(orig) == 'table' then 		copy = {} 		for orig_key, orig_value in pairs(orig) do 			copy[deepcopy(orig_key, includeMetatable, already_seen)] = deepcopy(orig_value, includeMetatable, already_seen) 		end 		already_seen[orig] = copy 		 		if includeMetatable then 			local mt = getmetatable(orig) 			if mt ~= nil then 				local mt_copy = deepcopy(mt, includeMetatable, already_seen) 				setmetatable(copy, mt_copy) 				already_seen[mt] = mt_copy 			end 		end 	else -- number, string, boolean, etc 		copy = orig 	end 	return copy end  function p.deepCopy(orig, noMetatable, already_seen) 	checkType("deepCopy", 3, already_seen, "table", true) 	 	return _deepCopy(orig, not noMetatable, already_seen) end  --[[ 	Concatenates all values in the table that are indexed by a number, in order. 	sparseConcat{ a, nil, c, d }  =>  "acd" 	sparseConcat{ nil, b, c, d }  =>  "bcd" ]] function p.sparseConcat(t, sep, i, j) 	local list = {} 	 	local list_i = 0 	for _, v in p.sparseIpairs(t) do 		list_i = list_i + 1 		list[list_i] = v 	end 	 	return table.concat(list, sep, i, j) end  --[[ -- This returns the length of a table, or the first integer key n counting from -- 1 such that t[n + 1] is nil. It is similar to the operator #, but may return -- a different value when there are gaps in the array portion of the table. -- Intended to be used on data loaded with mw.loadData. For other tables, use #. -- Note: #frame.args in frame object always be set to 0, regardless of  -- the number of unnamed template parameters, so use this function for -- frame.args. --]] function p.length(t) 	local i = 1 	while t[i] ~= nil do 		i = i + 1 	end 	return i - 1 end  function p.inArray(arr, valueToFind) 	checkType("inArray", 1, arr, "table") 	 	-- if valueToFind is nil, error? 	 	for _, v in ipairs(arr) do 		if v == valueToFind then 			return true 		end 	end 	 	return false end  return p