模块:TableTools

可在模块:TableTools/doc创建此模块的帮助文档

--[[
------------------------------------------------------------------------------------
--                               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 not rawequal(v,v)
end

-- 浅复制一个表。
function p.shallowClone(t)
	local ret = {}
	for k, v in pairs(t) do
		ret[k] = v
	end
	return ret
end

function p.shallowCloneArray(t)
	local ret = {}
	for k, v in ipairs(t) do
		ret[k] = v
	end
	return ret
end

-- 浅复制一个表，但是忽略元表。
function p.rawShallowClone(t)
	local ret
	for _, v in next, t do
		ret[t] = v
	end
	return ret
end

-- 往数组追加另一个数组的值。
function p.appendAll(t, another)
	for _, v in ipairs(another) do
		t[#t + 1] = v
	end
end

-- 从数组中移除重复值。
function p.removeDuplicates(t)
	local ret, exists = {}, {}
	for i, v in ipairs(t) do
		if not rawequal(v, 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

-- 返回有非nil值的数字键的表。
function p.numKeys(t)
	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

-- 返回含有所有数字键的表，包括小数、负数。
function p.allNumKeys(t)
	local nums = {}
	for k, v in pairs(t) do
		if type(k)=='number' then
			nums[#nums + 1] = k
		end
	end
	table.sort(nums)
	return nums
end

local function cleanPattern(s)
	-- Cleans a pattern so that the magic characters ()%.[]*+-?^$ are interpreted literally.
	return s:gsub('([%(%)%%%.%[%]%*%+%-%?%^%$])', '%%%1')
end

-- 搜索指定前后缀的整数键。
function p.affixNums(t, prefix, suffix)
	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

--搜索指定前后缀的所有数字键，不限于整数。
function p.allAffixNums(t, prefix, suffix)
	prefix = cleanPattern(prefix or '')
	suffix = cleanPattern(suffix or '')
	local pattern = string.format('^%s(.-)%s$', prefix, suffix)
	local nums = {}
	for k, v in pairs(t) do
		if type(k) == 'string' then
			nums[#nums + 1] = tonumber(mw.ustring.match(k, pattern))
		end
	end
	table.sort(nums)
end

-- 将有("foo1", "bar1", "foo2", "baz2")这样键的表转换成
-- { [1] = {foo = 'text', bar = 'text'}, [2] = {foo = 'text', baz = 'text'} }
-- compress函数用来压实表以便用ipairs迭代。
function p.numData(t, compress)
	checkType('numData', 1, t, 'table')
	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

-- 将像{a1='a1',b1='b1',a2='a2'}这样的表转换成
-- {a = {'a1', 'a2'}, b = {'b1'}}
-- 注意可能是稀疏数组。
-- pattern是正则表达式，匹配前缀和数字。
function p.allPrefixedNumKeys(t, pattern)
	local ret = {}
	for k, v in pairs(t) do
		local prefix, num = mw.ustring.match(tostring(k), pattern or '^([^0-9]*)([1-9][0-9]*)$')
		num = tonumber(num)
		if prefix and num then
			local subtable = ret[prefix] or {}
			subtable[num] = v
			ret[prefix] = subtable
		end
	end
	return ret
end
		

-- 将稀疏数组压实，移除nil值。
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

-- 将所有键为数字的字段转化成按数字大小排序的数组。
function p.compressExtendedSparseArray(t)
	checkType('compressExtendedSparseArray', 1, t, 'table')
	local ret = {}
	local nums = p.allNumKeys(t)
	for _, num in ipairs(nums) do
		ret[#ret + 1] = t[num]
	end
	return ret
end

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

function p.extendedSparseIpairs(t)
	checkType('extendedSparseIpairs', 1, t, 'table')
	local nums = p.allNumKeys(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

-- 返回表中字段的数量。
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

-- 返回表中字段的数量，但是忽略元表。
function p.rawSize(t)
	checkType('rawSize', 1, t, 'table')
	local i = 0
	for k in next, 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

-- 返回表中的键的列表，并使用默认比较函数或者自定义keySort函数比较。
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

-- 返回表中的键的列表，并使用默认比较函数或者自定义keySort函数比较，但是忽略元表。
function p.rawKeysToList(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 next, 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

-- 排序后迭代。
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

-- 排序后迭代，但是忽略元表。
function p.rawSortedPairs(t, keySort)
	checkType('sortedPairs', 1, t, 'table')
	checkType('sortedPairs', 2, keySort, 'function', true)
	
	local list = p.rawKeysToList(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

-- 判断一个表是否为严格的数组。
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

-- 递归深度拷贝，保护标识和子表。
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{ 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

function p.inArray(arr, valueToFind)
	checkType("inArray", 1, arr, "table")
	
	for _, v in ipairs(arr) do
		if v == valueToFind then
			return true
		end
	end
	
	return false
end

function p.visit(t,notNum)
	local keys = {}
	for k, v in pairs(t) do
		if type(k)=="number" then
			table.insert(keys,k)
		else
			if notNum then
	    		notNum(k,v,keys,t)
			end
		end
	end
	local i = 0
	return function()
		i = i+1
		return keys[i],key[i] and t[keys[i]]
	end
end

return p