Module:TableTools: Difference between revisions
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Template>Mr. Stradivarius (remove an unnecessary table.sort from compressSparseArray) |
Template>Mr. Stradivarius (use fooBar for function names instead of getFooBar) |
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--[[ | --[[ | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
-- | -- 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 07:25, 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