Difference between revisions of "Module:TableTools"
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en>Mr. Stradivarius (remove an unnecessary table.sort from compressSparseArray) |
en>Mr. Stradivarius (use fooBar for function names instead of getFooBar) |
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Line 35: | Line 35: | ||
--[[ | --[[ | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
-- | -- union | ||
-- | -- | ||
-- This returns the union of the values of n tables, as an array. For example, for | -- 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}, | -- the tables {1, 3, 4, 5, foo = 7} and {2, bar = 3, 5, 6}, union will return | ||
-- {1, 2, 3, 4, 5, 6, 7}. | -- {1, 2, 3, 4, 5, 6, 7}. | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
--]] | --]] | ||
function p. | function p.union(...) | ||
local tables = {...} | local tables = {...} | ||
local vals, ret = {}, {} | local vals, ret = {}, {} | ||
Line 59: | Line 59: | ||
--[[ | --[[ | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
-- | -- intersection | ||
-- | -- | ||
-- This returns the intersection of the values of n tables, as an array. For | -- This returns the intersection 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}, | -- example, for the tables {1, 3, 4, 5, foo = 7} and {2, bar = 3, 5, 6}, | ||
-- | -- intersection will return {3, 5}. | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
--]] | --]] | ||
function p. | function p.intersection(...) | ||
local tables = {...} | local tables = {...} | ||
local vals, ret = {}, {} | local vals, ret = {}, {} | ||
Line 87: | Line 87: | ||
--[[ | --[[ | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
-- | -- numKeys | ||
-- | -- | ||
-- This takes a table and returns an array containing the numbers of any numerical | -- This takes a table and returns an array containing the numbers of any numerical | ||
Line 93: | Line 93: | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
--]] | --]] | ||
function p. | function p.numKeys(t) | ||
local isPositiveInteger = p.isPositiveInteger | local isPositiveInteger = p.isPositiveInteger | ||
local nums = {} | local nums = {} | ||
Line 107: | Line 107: | ||
--[[ | --[[ | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
-- | -- affixNums | ||
-- | -- | ||
-- This takes a table and returns an array containing the numbers of keys with the | -- This takes a table and returns an array containing the numbers of keys with the | ||
-- specified prefix and suffix. For example, for the table | -- specified prefix and suffix. For example, for the table | ||
-- {a1 = 'foo', a3 = 'bar', a6 = 'baz'} and the prefix "a", | -- {a1 = 'foo', a3 = 'bar', a6 = 'baz'} and the prefix "a", affixNums will | ||
-- return {1, 3, 6}. | -- return {1, 3, 6}. | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
--]] | --]] | ||
function p. | function p.affixNums(t, prefix, suffix) | ||
prefix = prefix or '' | prefix = prefix or '' | ||
suffix = suffix or '' | suffix = suffix or '' | ||
Line 142: | Line 142: | ||
function p.compressSparseArray(t) | function p.compressSparseArray(t) | ||
local ret = {} | local ret = {} | ||
local nums = p. | local nums = p.numKeys(t) | ||
for _, num in ipairs(nums) do | for _, num in ipairs(nums) do | ||
ret[#ret + 1] = t[num] | ret[#ret + 1] = t[num] | ||
Line 158: | Line 158: | ||
--]] | --]] | ||
function p.sparseIpairs(t) | function p.sparseIpairs(t) | ||
local nums = p. | local nums = p.numKeys(t) | ||
local i = 0 | local i = 0 | ||
local lim = #nums | local lim = #nums |
Revision as of 01:55, 16 December 2013
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 p = {} -- Define often-used variables and functions. local floor = math.floor local infinity = math.huge --[[ ------------------------------------------------------------------------------------ -- isPositiveInteger -- -- This function returns true if the given number 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(num) if type(num) == 'number' and num >= 1 and floor(num) == num and num < infinity then return true else return false end end --[[ ------------------------------------------------------------------------------------ -- union -- -- 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.union(...) local tables = {...} local vals, ret = {}, {} for _, t in ipairs(tables) do for k, v in pairs(t) do vals[v] = true end end for val in pairs(vals) do ret[#ret + 1] = val end table.sort(ret) return ret end --[[ ------------------------------------------------------------------------------------ -- intersection -- -- This returns the intersection 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}, -- intersection will return {3, 5}. ------------------------------------------------------------------------------------ --]] function p.intersection(...) local tables = {...} local vals, ret = {}, {} local lim = #tables for _, t in ipairs(tables) do for k, v in pairs(t) do local valCount = vals[v] or 0 vals[v] = valCount + 1 end end for val, count in pairs(vals) do if count == lim then ret[#ret + 1] = val end end table.sort(ret) 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) 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) prefix = prefix or '' suffix = suffix or '' local nums = {} for k, v in pairs(t) do if type(k) == 'string' then local num = mw.ustring.match(k, '^' .. prefix .. '([1-9]%d*)' .. suffix .. '$') if num then nums[#nums + 1] = tonumber(num) end end end table.sort(nums) return nums 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) 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) 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] end end end return p