Difference between revisions of "Module:TableTools"

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en>Mr. Stradivarius
(clone tn rather than returning an altered tn)
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Line 17: Line 17:
local infinity = math.huge
local infinity = math.huge
local checkType = libraryUtil.checkType
local checkType = libraryUtil.checkType
 
local checkTypeMulti = libraryUtil.checkTypeMulti
-- Define a unique value to represent NaN. This is because NaN cannot be used as a table key.
local nan = {}


--[[
--[[
Line 25: Line 23:
-- isPositiveInteger
-- isPositiveInteger
--
--
-- This function returns true if the given number is a positive integer, and false
-- 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 31: Line 29:
------------------------------------------------------------------------------------
------------------------------------------------------------------------------------
--]]
--]]
function p.isPositiveInteger(num)
function p.isPositiveInteger(v)
if type(num) == 'number' and num >= 1 and floor(num) == num and num < infinity then
if type(v) == 'number' and v >= 1 and floor(v) == v and v < infinity then
return true
return true
else
else
Line 41: Line 39:
--[[
--[[
------------------------------------------------------------------------------------
------------------------------------------------------------------------------------
-- union
-- isNan
--
--
-- This returns the union of the key/value pairs of n tables. If any of the tables
-- This function returns true if the given number is a NaN value, and false
-- contain different values for the same table key, the table value is converted
-- if not. Although it doesn't operate on tables, it is included here as it is
-- to an array holding all of the different values.
-- 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.union(...)
function p.isNan(v)
local lim = select('#', ...)  
if type(v) == 'number' and tostring(v) == '-nan' then
if lim == 0 then
return true
error("no arguments passed to 'union'", 2)
else
return false
end
end
local ret, trackArrays = {}, {}
for i = 1, lim do
local t = select(i, ...)
checkType('union', i, t, 'table')
for k, v in pairs(t) do
local retKey = ret[k]
if retKey == nil then
ret[k] = v
elseif retKey ~= v then
if trackArrays[k] then
local array = ret[k]
local valExists
for _, arrayVal in ipairs(array) do
if arrayVal == v then
valExists = true
break
end
end
if not valExists then
array[#array + 1] = v
ret[k] = array
end
else
ret[k] = {ret[k], v}
trackArrays[k] = true
end
end
end
end
return ret
end
--[[
------------------------------------------------------------------------------------
-- valueUnion
--
-- This returns the union of the values of n tables, as an array. For example, for
-- the tables {1, 3, 4, 5, foo = 7} and {2, bar = 3, 5, 6}, union will return
-- {1, 2, 3, 4, 5, 6, 7}.
------------------------------------------------------------------------------------
--]]
function p.valueUnion(...)
local lim = select('#', ...)
if lim == 0 then
error("no arguments passed to 'valueUnion'", 2)
end
local vals, ret = {}, {}
for i = 1, lim do
local t = select(i, ...)
checkType('valueUnion', i, t, 'table')
for k, v in pairs(t) do
if type(v) == 'number' and tostring(v) == '-nan' then
v = nan -- NaN cannot be a table key, so use a proxy variable.
end
vals[v] = true
end
end
for val in pairs(vals) do
if val == nan then
-- This ensures that we output a NaN when we had one as input, although
-- they may have been generated in a completely different way.
val = 0/0
end
ret[#ret + 1] = val
end
return ret
end
--[[
------------------------------------------------------------------------------------
-- intersection
--
-- This returns the intersection of the key/value pairs of n tables. Both the key
-- and the value must match to be included in the resulting table.
------------------------------------------------------------------------------------
--]]
function p.intersection(...)
local lim = select('#', ...)
if lim == 0 then
error("no arguments passed to 'intersection'", 2)
end
local ret, track, pairCounts = {}, {}, {}
for i = 1, lim do
local t = select(i, ...)
checkType('intersection', i, t, 'table')
for k, v in pairs(t) do
local trackVal = track[k]
if trackVal == nil then
track[k] = v
pairCounts[k] = 1
elseif trackVal == v then
pairCounts[k] = pairCounts[k] + 1
end
end
end
for k, v in pairs(track) do
if pairCounts[k] == lim then
ret[k] = v
end
end
return ret
end
end


--[[
--[[
------------------------------------------------------------------------------------
------------------------------------------------------------------------------------
-- valueIntersection
-- shallowClone
--
--
-- This returns the intersection of the values of n tables, as an array. For
-- This returns a clone of a table. The value returned is a new table, but all
-- example, for the tables {1, 3, 4, 5, foo = 7} and {2, bar = 3, 5, 6},
-- subtables and functions are shared. Metamethods are respected, but the returned
-- intersection will return {3, 5}.
-- table will have no metatable of its own.
------------------------------------------------------------------------------------
------------------------------------------------------------------------------------
--]]
--]]
function p.valueIntersection(...)
function p.shallowClone(t)
local lim = select('#', ...)
local ret = {}
if lim == 0 then
for k, v in pairs(t) do
error("no arguments passed to 'valueIntersection'", 2)
ret[k] = v
end
local vals, ret = {}, {}
for i = 1, lim do
local t = select(i, ...)
checkType('valueIntersection', i, t, 'table')
for k, v in pairs(t) do
if type(v) == 'number' and tostring(v) == '-nan' then
v = nan -- NaN cannot be a table key, so use a proxy variable.
end
local valCount = vals[v] or 0
vals[v] = valCount + 1
end
end
for val, count in pairs(vals) do
if count == lim then
if val == nan then
-- This ensures that we output a NaN when we had one as input, although
-- they may have been generated in a completely different way.
val = 0/0
end
ret[#ret + 1] = val
end
end
end
return ret
return ret
Line 197: Line 74:
--[[
--[[
------------------------------------------------------------------------------------
------------------------------------------------------------------------------------
-- complement
-- removeDuplicates
--
--
-- This returns the relative complement of t1, t2, ..., in tn. The complement
-- This removes duplicate values from an array. Non-positive-integer keys are
-- is of key/value pairs. This is equivalent to all the key/value pairs that are in
-- ignored. The earliest value is kept, and all subsequent duplicate values are
-- tn but are not in t1, t2, ... tn-1.
-- removed, but otherwise the array order is unchanged.
------------------------------------------------------------------------------------
------------------------------------------------------------------------------------
--]]
--]]
function p.complement(...)
function p.removeDuplicates(t)
local lim = select('#', ...)
checkType('removeDuplicates', 1, t, 'table')
if lim == 0 then
local isNan = p.isNan
error("no arguments passed to 'complement' (minimum is two)", 2)
local ret, exists = {}, {}
elseif lim == 1 then
for i, v in ipairs(t) do
error("only one argument passed to 'complement' (minimum is two)", 2)
if isNan(v) then
end
-- NaNs can't be table keys, and they are also unique, so we don't need to check existence.
--[[
ret[#ret + 1] = v
-- Now we know that we have at least two sets.
else
-- First, get all the key/value pairs in tn. We can't simply make ret equal to tn,
if not exists[v] then
-- as that will affect the value of tn for the whole module.
ret[#ret + 1] = v
--]]
exists[v] = true
local tn = select(lim, ...)
checkType('complement', lim, tn, 'table')
local ret = {}
for k, v in pairs(tn) do
ret[k] = v
end
-- Remove all the key/value pairs in t1, t2, ..., tn-1.
for i = 1, lim - 1 do
local t = select(i, ...)
checkType('complement', i, t, 'table')
for k, v in pairs(t) do
if ret[k] == v then
ret[k] = nil
end
end
end
end
end
end
return ret
return ret
end
end


--[[
--[[
Line 270: Line 134:
checkType('affixNums', 2, prefix, 'string', true)
checkType('affixNums', 2, prefix, 'string', true)
checkType('affixNums', 3, suffix, '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 .. '$'
local nums = {}
local nums = {}
for k, v in pairs(t) do
for k, v in pairs(t) do
Line 284: Line 158:
table.sort(nums)
table.sort(nums)
return nums
return nums
end
--[[
------------------------------------------------------------------------------------
-- numData
--
-- Given a table with keys like ("foo1", "bar1", "foo2", "baz2"), returns a table
-- of subtables in the format
-- { [1] = {foo = 'text', bar = 'text'}, [2] = {foo = 'text', baz = 'text'} }
-- Keys that don't end with an integer are stored in a subtable named "other".
-- The compress option compresses the table so that it can be iterated over with
-- ipairs.
------------------------------------------------------------------------------------
--]]
function p.numData(t, compress)
checkType('numData', 1, t, 'table')
checkType('numData', 2, compress, 'boolean', true)
local ret = {}
for k, v in pairs(t) do
local prefix, num = mw.ustring.match(tostring(k), '^([^0-9]*)([1-9][0-9]*)$')
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 323: Line 238:
local key = nums[i]
local key = nums[i]
return key, t[key]
return key, t[key]
else
return nil, nil
end
end
end
end
Line 335: Line 252:
------------------------------------------------------------------------------------
------------------------------------------------------------------------------------
--]]
--]]
function p.size(t)
function p.size(t)
checkType('size', 1, t, 'table')
checkType('size', 1, t, 'table')
Line 342: Line 260:
end
end
return i
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
end


return p
return p

Latest revision as of 05:36, 19 July 2021

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)
	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