Documentation for this module may be created at Module:TableTools/doc

--[[--------------------------------------------------------------------------------------                               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.floorlocal infinity = math.hugelocal checkType = libraryUtil.checkTypelocal 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 thenreturn trueelsereturn falseendend--[[-------------------------------------------------------------------------------------- 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' thenreturn trueelsereturn falseendend--[[-------------------------------------------------------------------------------------- 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) doret[k] = vendreturn retend--[[-------------------------------------------------------------------------------------- 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.isNanlocal ret, exists = {}, {}for i, v in ipairs(t) doif 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] = velseif not exists[v] thenret[#ret + 1] = vexists[v] = trueendendendreturn retend--[[-------------------------------------------------------------------------------------- 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.isPositiveIntegerlocal nums = {}for k, v in pairs(t) doif isPositiveInteger(k) thennums[#nums + 1] = kendendtable.sort(nums)return numsend--[[-------------------------------------------------------------------------------------- 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('([%(%)%%%.%[%]%*%+%-%?%^%$])', '%%%1')return sendprefix = prefix or ''suffix = suffix or ''prefix = cleanPattern(prefix)suffix = cleanPattern(suffix)local pattern = '^' .. prefix .. '([1-9]%d*)' .. suffix .. '$'local nums = {}for k, v in pairs(t) doif type(k) == 'string' thenlocal num = mw.ustring.match(k, pattern)if num thennums[#nums + 1] = tonumber(num)endendendtable.sort(nums)return numsend--[[-------------------------------------------------------------------------------------- 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) dolocal prefix, num = mw.ustring.match(tostring(k), '^([^0-9]*)([1-9][0-9]*)$')if num thennum = 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 = 1endsubtable[prefix] = vret[num] = subtableelselocal subtable = ret.other or {}subtable[k] = vret.other = subtableendendif compress thenlocal other = ret.otherret = p.compressSparseArray(ret)ret.other = otherendreturn retend--[[-------------------------------------------------------------------------------------- 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) doret[#ret + 1] = t[num]endreturn retend--[[-------------------------------------------------------------------------------------- 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 = 0local lim = #numsreturn function ()i = i + 1if i <= lim thenlocal key = nums[i]return key, t[key]elsereturn nil, nilendendend--[[-------------------------------------------------------------------------------------- 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 = 0for k in pairs(t) doi = i + 1endreturn iendlocal function defaultKeySort(item1, item2)-- "number" < "string", so numbers will be sorted before strings.local type1, type2 = type(item1), type(item2)if type1 ~= type2 thenreturn type1 < type2else -- This will fail with table, boolean, function.return item1 < item2endend--[[Returns a list of the keys in a table, sorted using either a defaultcomparison function or a custom keySort function.]]function p.keysToList(t, keySort, checked)if not checked thencheckType('keysToList', 1, t, 'table')checkTypeMulti('keysToList', 2, keySort, { 'function', 'boolean', 'nil' })endlocal list = {}local index = 1for key, value in pairs(t) dolist[index] = keyindex = index + 1endif keySort ~= false thenkeySort = type(keySort) == 'function' and keySort or defaultKeySorttable.sort(list, keySort)endreturn listend--[[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 = 0return function()i = i + 1local key = list[i]if key ~= nil thenreturn key, t[key]elsereturn nil, nilendendend--[[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 = 0for k, v in pairs(t) doi = i + 1if t[i] == nil thenreturn falseendendreturn trueend-- { "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) domap[v] = iendreturn mapend--[[{ "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) doset[item] = trueendreturn setend--[[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 thenreturn copyendif type(orig) == 'table' thencopy = {}for orig_key, orig_value in pairs(orig) docopy[deepcopy(orig_key, includeMetatable, already_seen)] = deepcopy(orig_value, includeMetatable, already_seen)endalready_seen[orig] = copyif includeMetatable thenlocal mt = getmetatable(orig)if mt ~= nil thenlocal mt_copy = deepcopy(mt, includeMetatable, already_seen)setmetatable(copy, mt_copy)already_seen[mt] = mt_copyendendelse -- number, string, boolean, etccopy = origendreturn copyendfunction 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 = 0for _, v in p.sparseIpairs(t) dolist_i = list_i + 1list[list_i] = vendreturn 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 = 1while t[i] ~= nil doi = i + 1endreturn i - 1endfunction p.inArray(arr, valueToFind)checkType("inArray", 1, arr, "table")-- if valueToFind is nil, error?for _, v in ipairs(arr) doif v == valueToFind thenreturn trueendendreturn falseendreturn p
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