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Module:TableTools

Template:High-use

本模块包含一系列用于处理Lua表的函数。这是个元模块，用于其他Lua模块调用，而不应该由#invoke直接调用。

加载模块

编辑

如需加载任何函数，首先需要加载模块。 

local TableTools = require('Module:TableTools')

isPositiveInteger

编辑 
TableTools.isPositiveInteger(value)

如果value是正整数，返回true，否则返回false。虽然此函数不是应用于表的，但这里仍收录了此函数以决定一个给定的键是否在表的数组部分或哈希部分。

isNan

编辑 
TableTools.isNan(value)

如果value是NaN值，返回true，否则返回false。虽然此函数不是应用于表的，但这里仍收录了此函数以决定一个值能否作为有效的键。（将NaN作为键会报错。）

shallowClone

编辑 
TableTools.shallowClone(t)

返回表格的副本。返回的值是一个新表，但是所有的子表和函数都会共用。不会绕过元表，但返回的表自身不会带有元表。如需在创建新表时不共享子表格且要复制元表，可以使用mw.clone。

removeDuplicates

编辑 
TableTools.removeDuplicates(t)

从数组中返回重复值。此函数仅用于标准的数组，所有非正整数键的一律忽略，第一个nil后的值也会忽略。（对于包含nil的数组，可以先使用compressSparseArray。）此函数尝试保护数组的顺序：有重复值时，仅保留最早出现的那个。例如，对于表Template:Code，removeDuplicates返回Template:Code。

numKeys

编辑 
TableTools.numKeys(t)

接收表t并以数字顺序返回拥有非nil值的正整数键的数量。例如，对于Template:Code，numKeys返回Template:Code。

affixNums

编辑 
TableTools.affixNums(t, prefix, suffix)

接收表t并返回包含含有可选前缀prefix和可选后缀suffix的键的数量的数组。例如，对于表Template:Code和前缀'a'，affixNums返回Template:Code。prefix和suffix的值均按字面解释（不使用正则表达式）。

numData

编辑 
TableTools.numData(t, compress)

假如一个表有像foo1、bar1、foo2、baz2这样的键，返回如下格式的子表的表Template:Code。不以整数结尾的键存储在命名为other的子表中。compress选项会压缩表以便通过ipairs迭代。

compressSparseArray

编辑 
TableTools.compressSparseArray(t)

接收一个带有一个或更多nil值的数组t，移除所有的nil值，不影响其他值的顺序，以便于安全地通过ipairs遍历。所有非正整数的键都会移除。例如，对于表Template:Code，compressSparseArray返回Template:Code。

sparseIpairs

编辑 
TableTools.sparseIpairs(t)

这是用于遍历稀疏数组t的迭代器函数。类似于ipairs，但会一直迭代直到最高的数字键，而ipairs遇到第一个nil就可能会终止。忽略所有的非正整数键。

sparseIpairs常用于通用的for循环。 

for i, v in TableTools.sparseIpairs(t) do
   -- 代码
end

注意sparseIpairs会在实现时使用pairs。尽管一些键看上去被忽略，但实际上运行时也会遍历到。

size

编辑 
TableTools.size(t)

寻找“键/值对”表的大小。例如，对于Template:Code，size返回2。函数也可以用于数组，但是对于数组，使用#操作符更高效。注意，为了查找表的大小，函数会使用pairs函数以遍历所有的表键。

keysToList

编辑 
TableTools.keysToList(t, keySort)

返回表的键的列表，并按默认比较函数或者自定义keySort函数排序，与table.sort的comp函数类似。

sortedPairs

编辑 
TableTools.sortedPairs(t, keySort)

迭代表，并使用keysToList函数来排序键。如果只有数字键，sparseIpairs可能更高效。

isArray

编辑 
TableTools.isArray(t)

如果表中的所有键都是以1开始的接连不断的整数，返回true。

listToSet

编辑 
TableTools.listToSet(arr)

从表arr的数组部分创建一个集（set）。用arr的任何值来索引集都会返回true。 

local set = TableTools.listToSet { "a", "b", "c" }
assert(set["a"] == true)

invert

编辑 
TableTools.invert(t)

交换数组中的键和值。例如，invert{ "a", "b", "c" }产生{ a = 1, b = 2, c = 3 }。

deepCopy

编辑 
TableTools.deepCopy(orig, noMetatable, alreadySeen)

返回表orig的副本，类似于mw.clone，所有非函数的值都会复制，并保留表的唯一性。如果noMetatable为true，则不会复制元表（如有）。可以复制由mw.loadData加载的表。

与mw.clone类似，但mw.clone不能够复制由mw.loadData加载的表，也不允许拒绝复制元表。

sparseConcat

编辑 
TableTools.sparseConcat(t, sep)

按顺序连接被正整数索引的表的所有值。

length

编辑 
TableTools.length(t)

查找数组的长度，或者带有像data1、data2这样的键的准数组。使用指数搜索算法以查找长度，以便于尽可能少地使用表查找（table lookup）。

对于准数组，此算法对使用元表的数组有用（例如frame.args）。对于正常数组，只需要使用#操作符，因为#操作符是由C语言实现的，速度更快。

inArray

编辑 
TableTools.inArray(arr, valueToFind)

如果valueToFind是数组arr的成员，返回true，否则返回false。 

-- 本頁面複製自[[w:zh:Module:TableTools]]，由機器人定期更新。請直接編輯原維基項目頁面，或自設定頁面[[User:Cewbot/log/20211203/configuration]]去除本頁面之後再編輯。
------------------------------------------------------------------------------------
--                                   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)
	return type(v) == 'number' and v >= 1 and floor(v) == v and v < infinity
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)
	return type(v) == 'number' and v ~= v
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)
	checkType('shallowClone', 1, t, 'table')
	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(arr)
	checkType('removeDuplicates', 1, arr, 'table')
	local isNan = p.isNan
	local ret, exists = {}, {}
	for _, v in ipairs(arr) 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 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.
		return s:gsub('([%(%)%%%.%[%]%*%+%-%?%^%$])', '%%%1')
	end

	prefix = prefix or ''
	suffix = suffix or ''
	prefix = cleanPattern(prefix)
	suffix = cleanPattern(suffix)
	local pattern = '^' .. prefix .. '([1-9]%d*)' .. suffix .. '$'

	local nums = {}
	for k 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 _ 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
	elseif type1 == 'table' or type1 == 'boolean' or type1 == 'function' then
		return tostring(item1) < tostring(item2)
	else
		return item1 < item2
	end
end
------------------------------------------------------------------------------------
-- keysToList
--
-- Returns an array 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 arr = {}
	local index = 1
	for k in pairs(t) do
		arr[index] = k
		index = index + 1
	end

	if keySort ~= false then
		keySort = type(keySort) == 'function' and keySort or defaultKeySort
		table.sort(arr, keySort)
	end

	return arr
end

------------------------------------------------------------------------------------
-- sortedPairs
--
-- 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 arr = p.keysToList(t, keySort, true)

	local i = 0
	return function ()
		i = i + 1
		local key = arr[i]
		if key ~= nil then
			return key, t[key]
		else
			return nil, nil
		end
	end
end

------------------------------------------------------------------------------------
-- isArray
--
-- Returns true if the given value is a table and all keys are consecutive
-- integers starting at 1.
------------------------------------------------------------------------------------
function p.isArray(v)
	if type(v) ~= 'table' then
		return false
	end
	local i = 0
	for _ in pairs(v) do
		i = i + 1
		if v[i] == nil then
			return false
		end
	end
	return true
end

------------------------------------------------------------------------------------
-- isArrayLike
--
-- Returns true if the given value is iterable and all keys are consecutive
-- integers starting at 1.
------------------------------------------------------------------------------------
function p.isArrayLike(v)
	if not pcall(pairs, v) then
		return false
	end
	local i = 0
	for _ in pairs(v) do
		i = i + 1
		if v[i] == nil then
			return false
		end
	end
	return true
end

------------------------------------------------------------------------------------
-- invert
--
-- Transposes the keys and values in an array. For example, {"a", "b", "c"} ->
-- {a = 1, b = 2, c = 3}. Duplicates are not supported (result values refer to
-- the index of the last duplicate) and NaN values are ignored.
------------------------------------------------------------------------------------
function p.invert(arr)
	checkType("invert", 1, arr, "table")
	local isNan = p.isNan
	local map = {}
	for i, v in ipairs(arr) do
		if not isNan(v) then
			map[v] = i
		end
	end

	return map
end

------------------------------------------------------------------------------------
-- listToSet
--
-- Creates a set from the array part of the table. Indexing the set by any of the
-- values of the array returns true. For example, {"a", "b", "c"} ->
-- {a = true, b = true, c = true}. NaN values are ignored as Lua considers them
-- never equal to any value (including other NaNs or even themselves).
------------------------------------------------------------------------------------
function p.listToSet(arr)
	checkType("listToSet", 1, arr, "table")
	local isNan = p.isNan
	local set = {}
	for _, v in ipairs(arr) do
		if not isNan(v) then
			set[v] = true
		end
	end

	return set
end

------------------------------------------------------------------------------------
-- deepCopy
--
-- 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

------------------------------------------------------------------------------------
-- sparseConcat
--
-- 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 arr = {}

	local arr_i = 0
	for _, v in p.sparseIpairs(t) do
		arr_i = arr_i + 1
		arr[arr_i] = v
	end

	return table.concat(arr, sep, i, j)
end

------------------------------------------------------------------------------------
-- length
--
-- Finds the length of an array, or of a quasi-array with keys such as "data1",
-- "data2", etc., using an exponential search algorithm. 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, prefix)
	-- requiring module inline so that [[Module:Exponential search]] which is
	-- only needed by this one function doesn't get millions of transclusions
	local expSearch = require("Module:Exponential search")
	checkType('length', 1, t, 'table')
	checkType('length', 2, prefix, 'string', true)
	return expSearch(function (i)
		local key
		if prefix then
			key = prefix .. tostring(i)
		else
			key = i
		end
		return t[key] ~= nil
	end) or 0
end

------------------------------------------------------------------------------------
-- inArray
--
-- Returns true if valueToFind is a member of the array, and false otherwise.
------------------------------------------------------------------------------------
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
检索自“https://zh.wikinews.org/w/index.php?title=Module:TableTools&oldid=219793”