Module:Enum

Module documentation

This documentation is transcluded from Module:Enum/doc. [edit] [history] [purge]

Module:Enum requires Module:LibraryUtil.

Module:Enum is required by Module:DependencyList.

This module is a helper module to be used by other modules; it may not be designed to be invoked directly. See Near-Reality:Lua/Helper modules for a full list and more information.

Module	Function	Type	Use
Enum	any(enum, [fn], [clone|false])	table, function/nil, boolean/nil	Loops over the array part of enum and passes each element as the first argument to fn. If fn returns true for at least one element then any() returns true, otherwise false. If no function is given function(item) return item end is used. If clone is true the input enum is deep copied using mw.clone() before use.
	all(enum, [fn], [clone|false])	table, function/nil, boolean/nil	Loops over the array part of enum and passes each element as the first argument to fn. If fn returns true for all elements then all() returns true, otherwise false. If no function is given function(item) return item end is used.
	each(enum, fn, [clone|false])	table, function, boolean/nil	Loops over the array part of enum and passes each element as the first argument to fn. This function returns nothing.
	sum(enum, [clone|false])	table, boolean/nil	Returns the sum of all array elements in enum.
	reduce(enum, fn, [accumulator|enum[1]], [clone|false])	table, function, any, boolean/nil	Loops over the array part of enum and passes each element as the first argument and accumulator as the second to fn. The return value of fn becomes the new accumulator. The final value of accumulator is returned. If no accumulator is given then the first element in enum is used.
	scan(enum, fn, [accumulator|enum[1]], [clone|false])	table, function, any, boolean/nil	Same as reduce() but each step is appended to a table. This table is then returned.
	find(enum, fn, [default|nil], [clone|false])	table, function, any, boolean/nil	Loops over the array part of enum and passes each element as the first argument to fn. The first element where fn returns true is returned. If no elements passes the test, default is returned.
	find_index(enum, fn, [default|nil], [clone|false])	table, function, any, boolean/nil	Loops over the array part of enum and passes each element as the first argument to fn. The index of the first element where fn returns true is returned. If no elements passes the test, default is returned.
	max_by(enum, fn, [clone|false])	table, function, boolean/nil	Loops over the array part of enum and passes each element as the first argument to fn. max_by() returns two values, the first is the element where fn returned the largest value, the second is this largest value. The > operator is used for the comparisons.
	map(enum, fn, [clone|false])	table, function, boolean/nil	Loops over the array part of enum and passes each element as the first argument to fn. The return value of fn is appended to a new table. This new table is returned.
	filter(enum, [fn], [clone|false])	table, function/nil, boolean/nil	Loops over the array part of enum and passes each element as the first argument to fn. If fn returns true the corresponding element is copied to a new table which is then returned. If no function is given function(item) return item end is used.
	reject(enum, [fn], [clone|false])	table, function, boolean/nil	The opposite of filter().
	split(enum, count, [clone|false])	table, number, boolean/nil	Returns two tables where the first is equivalent to slice(enum, 1, count) and the second slice(enum, count+1, #enum).
	slice(enum, [start|1], [stop|#enum], [clone|false])	table, number/nil, number/nil, boolean/nil	Returns a table containing all the elements of enum between the start and stop indices. The start and stop indices are inclusive.
	take(enum, count, [clone|false])	table, number, boolean/nil	Returns only the first table of split(enum, count).
	take_every(enum, n, [clone|false])	table, number, boolean/nil	Returns a table containing every nth element of enum.
	unique(enum, [fn], [clone|false])	table, function/nil, boolean/nil	Returns a new table where all duplicate values in enum are removed. In case a duplicate is present, the element with the lowest index will be kept and every subsequent duplicate element is removed. fn can be used to create a custom id for every element so that the result is a table with elements which all create a unique id. If no function is given function(item) return item end is used.
	zip(enums, [clone|false])	table, boolean/nil	Groups elements with the same indexes from different arrays together, i.e. zip{ {a1, a2, a3}, {b1, b2, b3}, {c1, c2} } -> {{a1, b1, c1}, {a2, b2, c2}, {a3, b3}}
	intersect(enum1, enum2, [clone|false])	table, table, boolean/nil	Returns true if both sets have at least one element with equal values.
	contains(enum, elem, [clone|false])	table, any, boolean/nil	Returns true if enum contains elem, otherwise returns false.
	take_from(enum, index, count)	table, number, number	Returns count number of elements, starting at index

---

-- <nowiki> awawa
local libraryUtil = require('libraryUtil')
local checkType = libraryUtil.checkType
local checkTypeMulti = libraryUtil.checkTypeMulti
local p = {}

function p.all(enum, fn, clone)
	checkType('Module:Enum.all', 1, enum, 'table')
	checkType('Module:Enum.all', 2, fn, 'function', true)
	checkType('Module:Enum.all', 3, clone, 'boolean', true)
	if clone then enum = mw.clone(enum) end
	fn = fn or function(item) return item end
	for _, item in ipairs(enum) do
		if not fn(item) then
			return false
		end
	end
	return true
end

function p.any(enum, fn, clone)
	checkType('Module:Enum.any', 1, enum, 'table')
	checkType('Module:Enum.any', 2, fn, 'function', true)
	checkType('Module:Enum.any', 3, clone, 'boolean', true)
	if clone then enum = mw.clone(enum) end
	fn = fn or function(item) return item end
	for _, item in ipairs(enum) do
		if fn(item) then
			return true
		end
	end
	return false
end

function p.contains(enum, elem, clone)
	checkType('Module:Enum.contains', 1, enum, 'table')
	checkType('Module:Enum.contains', 3, clone, 'boolean', true)
	if clone then enum = mw.clone(enum); elem = mw.clone(elem) end
	return p.any(enum, function(item) return item == elem end)
end

function p.each(enum, fn, clone)
	checkType('Module:Enum.each', 1, enum, 'table')
	checkType('Module:Enum.each', 2, fn, 'function')
	checkType('Module:Enum.each', 3, clone, 'boolean', true)
	if clone then enum = mw.clone(enum) end
	for _, item in ipairs(enum) do
		fn(item)
	end
end

function p.filter(enum, fn, clone)
	checkType('Module:Enum.filter', 1, enum, 'table')
	checkType('Module:Enum.filter', 2, fn, 'function', true)
	checkType('Module:Enum.filter', 3, clone, 'boolean', true)
	if clone then enum = mw.clone(enum) end
	fn = fn or function(item) return item end
	local r = {}
	for _, item in ipairs(enum) do
		if fn(item) then
			table.insert(r, item)
		end
	end
	return r
end

function p.find(enum, fn, default, clone)
	checkType('Module:Enum.find', 1, enum, 'table')
	checkType('Module:Enum.find', 2, fn, 'function')
	checkType('Module:Enum.find', 4, clone, 'boolean', true)
	if clone then enum = mw.clone(enum); default = mw.clone(default) end
	for _, item in ipairs(enum) do
		if fn(item) then
			return item
		end
	end
	return default
end

function p.find_index(enum, fn, default, clone)
	checkType('Module:Enum.find_index', 1, enum, 'table')
	checkType('Module:Enum.find_index', 2, fn, 'function')
	checkType('Module:Enum.find_index', 4, clone, 'boolean', true)
	if clone then enum = mw.clone(enum); default = mw.clone(default) end
	for index, item in ipairs(enum) do
		if fn(item) then
			return index
		end
	end
	return default
end

function p.newIncrementor(start, step)
	checkType('Module:Enum.newIncrementor', 1, start, 'number', true)
	checkType('Module:Enum.newIncrementor', 2, step, 'number', true)
	step = step or 1
	local n = (start or 1) - step
	local obj = {}
	return setmetatable(obj, {
		__call = function() n = n + step return n end,
		__tostring = function() return n end,
		__index = function() return n end,
		__newindex = function(self, k, v)
			if k == 'step' and type(v) == 'number' then
				step = v
			elseif type(v) == 'number' then
				n = v
			end
		end,
		__concat = function(x, y) return tostring(x) .. tostring(y) end
	})
end

function p.intersect(enum1, enum2, clone)
	checkType('Module:Enum.intersect', 1, enum1, 'table')
	checkType('Module:Enum.intersect', 2, enum2, 'table')
	checkType('Module:Enum.intersect', 3, clone, 'boolean', true)
	if clone then enum1 = mw.clone(enum1); enum2 = mw.clone(enum2) end
	local enum2Elements = {}
	local res = {}
	p.each(enum2, function(item) enum2Elements[item] = true end)
	p.each(enum1, function(item)
		if enum2Elements[item] then
			table.insert(res, item)
		end
	end)
	return res
end

function p.intersects(enum1, enum2, clone)
	checkType('Module:Enum.intersects', 1, enum1, 'table')
	checkType('Module:Enum.intersects', 2, enum2, 'table')
	checkType('Module:Enum.intersects', 3, clone, 'boolean', true)
	if clone then enum1 = mw.clone(enum1); enum2 = mw.clone(enum2) end
	return p.any(enum1, function(item1) return p.any(enum2, function(item2) return item1==item2 end) end)
end

function p.insert(enum1, enum2, index, clone)
	checkType('Module:Enum.insert', 1, enum1, 'table')
	checkType('Module:Enum.insert', 2, enum2, 'table')
	checkType('Module:Enum.insert', 3, index, 'number', true)
	checkType('Module:Enum.insert', 4, clone, 'boolean', true)
	if clone then enum1 = mw.clone(enum1); enum2 = mw.clone(enum2) end
	local len1 = #enum1
	local len2 = #enum2
	index = index or (len1 + 1)
	local res = {}

	for i = 1, (len1 + len2) do
		if i < index then
			res[i] = enum1[i]
		elseif i < (index + len2) then
			res[i] = enum2[i - index + 1]
		else
			res[i] = enum1[i - len2]
		end
	end

	return res
end

function p.map(enum, fn, clone)
	checkType('Module:Enum.map', 1, enum, 'table')
	checkType('Module:Enum.map', 2, fn, 'function')
	checkType('Module:Enum.map', 3, clone, 'boolean', true)
	if clone then enum = mw.clone(enum) end
	local r = {}
	for _, item in ipairs(enum) do
		local temp = fn(item) -- Only use first returned item
		table.insert(r, temp)
	end
	return r
end

function p.max_by(enum, fn, clone)
	checkType('Module:Enum.max_by', 1, enum, 'table')
	checkType('Module:Enum.max_by', 2, fn, 'function')
	checkType('Module:Enum.max_by', 3, clone, 'boolean', true)
	if clone then enum = mw.clone(enum) end
	return unpack(p.reduce(enum, function(new, old)
		local y = fn(new)
		return y > old[2] and {new, y} or old
	end, {0, 0}))
end

function p.range(start, stop, step)
	checkType('Module:Enum.range', 1, start, 'number')
	checkType('Module:Enum.range', 2, stop, 'number', true)
	checkType('Module:Enum.range', 3, step, 'number', true)
	local array = {}
	if not stop then
		stop = start
		start = 1
	end
	local j = 1
	for i = start, stop, step or 1 do
		array[j] = i
		j = j + 1
	end
	return array
end

function p.reduce(enum, fn, accumulator, clone)
	checkType('Module:Enum.reduce', 1, enum, 'table')
	checkType('Module:Enum.reduce', 2, fn, 'function')
	checkType('Module:Enum.reduce', 4, clone, 'boolean', true)
	if clone then enum = mw.clone(enum); accumulator = mw.clone(accumulator) end
	local acc = accumulator
	for index, item in ipairs(enum) do
		if index == 1 and not accumulator then
			acc = item
		else
			acc = fn(item, acc)
		end
	end
	return acc
end

function p.reject(enum, fn, clone)
	checkType('Module:Enum.reject', 1, enum, 'table')
	checkTypeMulti('Module:Enum.reject', 2, fn, {'function', 'table', 'nil'})
	checkType('Module:Enum.reject', 3, clone, 'boolean', true)
	if clone then enum = mw.clone(enum) end
	fn = fn or function(item) return item end
	local r = {}
	if type(fn) == 'function' then
		for index, item in ipairs(enum) do
			if not fn(item, index) then
				table.insert(r, item)
			end
		end
	else
		local rejectMap = {}
		for _, item in ipairs(fn) do
			rejectMap[item] = true
		end
		for _, item in ipairs(enum) do
			if not rejectMap[item] then
				table.insert(r, item)
			end
		end
	end
	return r
end

function p.scan(enum, fn, accumulator, clone)
	checkType('Module:Enum.scan', 1, enum, 'table')
	checkType('Module:Enum.scan', 2, fn, 'function')
	checkType('Module:Enum.scan', 4, clone, 'boolean', true)
	if clone then enum = mw.clone(enum); accumulator = mw.clone(accumulator) end
	local acc = accumulator
	local r = {}
	for index, item in ipairs(enum) do
		if index == 1 and not accumulator then
			acc = item
		else
			acc = fn(item, acc)
		end
		table.insert(r, acc)
	end
	return r
end

function p.slice(enum, start, finish, clone)
	checkType('Module:Enum.slice', 1, enum, 'table')
	checkType('Module:Enum.slice', 2, start, 'number', true)
	checkType('Module:Enum.slice', 3, finish, 'number', true)
	checkType('Module:Enum.slice', 4, clone, 'boolean', true)
	if clone then enum = mw.clone(enum) end
	start = start or 1
	finish = finish or #enum
	local r = {}
	for index, item in ipairs(enum) do
		if index >= start and index <= finish then
			table.insert(r, item)
		end
	end
	return r
end

function p.split(enum, count, clone)
	checkType('Module:Enum.split', 1, enum, 'table')
	checkType('Module:Enum.split', 2, count, 'number')
	checkType('Module:Enum.split', 3, clone, 'boolean', true)
	if clone then enum = mw.clone(enum) end
	if #enum < count then
		return enum, {}
	elseif count < 1 then
		return {}, enum
	end

	local x = {}
	local y = {}

	for i = 1, #enum do
		table.insert(
			i <= count and x or y,
			enum[i]
		)
	end
	return x, y
end

function p.sum(enum, clone)
	checkType('Module:Enum.sum', 1, enum, 'table')
	checkType('Module:Enum.sum', 2, clone, 'boolean', true)
	if clone then enum = mw.clone(enum) end
	return p.reduce(enum, function(x, y) return x + y end)
end

function p.take(enum, count, clone)
	checkType('Module:Enum.take', 1, enum, 'table')
	checkType('Module:Enum.take', 2, count, 'number')
	checkType('Module:Enum.take', 3, clone, 'boolean', true)
	if clone then enum = mw.clone(enum) end
	local x, _ = p.split(enum, count)
	return x
end

function p.take_every(enum, n, clone)
	checkType('Module:Enum.take_every', 1, enum, 'table')
	checkType('Module:Enum.take_every', 2, n, 'number')
	checkType('Module:Enum.take_every', 3, clone, 'boolean', true)
	if clone then enum = mw.clone(enum) end
	local r = {}
	for index, item in ipairs(enum) do
		if (index - 1) % n == 0 then
			table.insert(r, item)
		end
	end
	return r
end

function p.take_from(enum, index, count)
	checkType('Module:Enum.take_from', 1, enum, 'table')
	checkType('Module:Enum.take_from', 2, index, 'number')
	checkType('Module:Enum.take_from', 3, count, 'number')
	local x, _ = p.split(p.reject(enum,
		function(item, idx)
			return idx < index
		end
	), count)
	return x
end

function p.unique(enum, fn, clone)
	checkType('Module:Enum.unique', 1, enum, 'table')
	checkType('Module:Enum.unique', 2, fn, 'function', true)
	checkType('Module:Enum.unique', 3, clone, 'boolean', true)
	if clone then enum = mw.clone(enum) end
	fn = fn or function(item) return item end
	local r = {}
	local hash = {}
	for _, item in ipairs(enum) do
		local id = fn(item)
		if not hash[id] then
			table.insert(r, item)
			hash[id] = true
		end
	end
	return r
end

function p.zip(enums, clone)
	checkType('Module:Enum.zip', 1, enums, 'table')
	checkType('Module:Enum.zip', 2, clone, 'boolean', true)
	if clone then enums = mw.clone(enums) end
	local r = {}
	local _, longest = p.max_by(enums, function(enum) return #enum end)
	for i = 1, longest do
		local q = {}
		for j = 1, #enums do
			table.insert(q, enums[j][i])
		end
		table.insert(r, q)
	end
	return r
end

return p
-- </nowiki>