Difference between revisions of "Module:TableTools"
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------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
--]] | --]] | ||
+ | |||
+ | local libraryUtil = require('libraryUtil') | ||
local p = {} | local p = {} | ||
Line 14: | Line 16: | ||
local floor = math.floor | local floor = math.floor | ||
local infinity = math.huge | local infinity = math.huge | ||
− | + | local checkType = libraryUtil.checkType | |
− | + | local checkTypeMulti = libraryUtil.checkTypeMulti | |
− | local | ||
--[[ | --[[ | ||
Line 22: | Line 23: | ||
-- isPositiveInteger | -- isPositiveInteger | ||
-- | -- | ||
− | -- This function returns true if the given | + | -- 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 | -- 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 | -- useful for determining whether a given table key is in the array part or the | ||
Line 28: | Line 29: | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
--]] | --]] | ||
− | function p.isPositiveInteger( | + | 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 tostring(v) == '-nan' | ||
end | end | ||
--[[ | --[[ | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
− | -- | + | -- shallowClone |
-- | -- | ||
− | -- This returns | + | -- 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. | + | function p.shallowClone(t) |
− | local | + | local ret = {} |
− | + | for k, v in pairs(t) do | |
− | + | ret[k] = v | |
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | |||
− | ret[ | ||
end | end | ||
return ret | return ret | ||
− | end | + | end |
--[[ | --[[ | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
− | -- | + | -- removeDuplicates |
-- | -- | ||
− | -- This | + | -- 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. | + | function p.removeDuplicates(t) |
− | + | checkType('removeDuplicates', 1, t, 'table') | |
− | local | + | 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 | |
− | |||
− | |||
− | |||
− | if | ||
− | |||
− | |||
− | |||
end | end | ||
− | + | end | |
− | end | ||
end | end | ||
return ret | return ret | ||
− | end | + | end |
--[[ | --[[ | ||
Line 111: | Line 100: | ||
--]] | --]] | ||
function p.numKeys(t) | function p.numKeys(t) | ||
+ | checkType('numKeys', 1, t, 'table') | ||
local isPositiveInteger = p.isPositiveInteger | local isPositiveInteger = p.isPositiveInteger | ||
local nums = {} | local nums = {} | ||
Line 133: | Line 123: | ||
--]] | --]] | ||
function p.affixNums(t, prefix, suffix) | 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('([%(%)%%%.%[%]%*%+%-%?%^%$])', '%%%1') | ||
+ | return s | ||
+ | end | ||
+ | |||
prefix = prefix or '' | prefix = prefix or '' | ||
suffix = suffix or '' | suffix = suffix or '' | ||
+ | prefix = cleanPattern(prefix) | ||
+ | suffix = cleanPattern(suffix) | ||
local pattern = '^' .. prefix .. '([1-9]%d*)' .. suffix .. '$' | local pattern = '^' .. prefix .. '([1-9]%d*)' .. suffix .. '$' | ||
+ | |||
local nums = {} | local nums = {} | ||
for k, v in pairs(t) do | for k, v in pairs(t) do | ||
Line 147: | Line 150: | ||
table.sort(nums) | table.sort(nums) | ||
return nums | return nums | ||
+ | end | ||
+ | |||
+ | --[[ | ||
+ | ------------------------------------------------------------------------------------ | ||
+ | -- numData | ||
+ | -- | ||
+ | -- Given a table with keys like ("foo1", "bar1", "foo2", "baz2"), returns a table | ||
+ | -- of subtables in the format | ||
+ | -- { [1] = {foo = 'text', bar = 'text'}, [2] = {foo = 'text', baz = 'text'} } | ||
+ | -- Keys that don't end with an integer are stored in a subtable named "other". | ||
+ | -- The compress option compresses the table so that it can be iterated over with | ||
+ | -- ipairs. | ||
+ | ------------------------------------------------------------------------------------ | ||
+ | --]] | ||
+ | function p.numData(t, compress) | ||
+ | checkType('numData', 1, t, 'table') | ||
+ | checkType('numData', 2, compress, 'boolean', true) | ||
+ | local ret = {} | ||
+ | for k, v in pairs(t) do | ||
+ | local prefix, num = mw.ustring.match(tostring(k), '^([^0-9]*)([1-9][0-9]*)$') | ||
+ | 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 | end | ||
Line 159: | Line 203: | ||
--]] | --]] | ||
function p.compressSparseArray(t) | function p.compressSparseArray(t) | ||
+ | checkType('compressSparseArray', 1, t, 'table') | ||
local ret = {} | local ret = {} | ||
local nums = p.numKeys(t) | local nums = p.numKeys(t) | ||
Line 176: | Line 221: | ||
--]] | --]] | ||
function p.sparseIpairs(t) | function p.sparseIpairs(t) | ||
+ | checkType('sparseIpairs', 1, t, 'table') | ||
local nums = p.numKeys(t) | local nums = p.numKeys(t) | ||
local i = 0 | local i = 0 | ||
Line 184: | Line 230: | ||
local key = nums[i] | local key = nums[i] | ||
return key, t[key] | 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 | ||
+ | |||
+ | --[[ | ||
+ | -- Finds the length of an array, or of a quasi-array with keys such | ||
+ | -- as "data1", "data2", etc., using an exponental 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:Exponental 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 | ||
+ | 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 | ||
end | end | ||
+ | |||
+ | return false | ||
end | end | ||
return p | return p |
Latest revision as of 14:34, 9 March 2020
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.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 tostring(v) == '-nan' 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 --[[ -- Finds the length of an array, or of a quasi-array with keys such -- as "data1", "data2", etc., using an exponental 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:Exponental 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 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