Module:TableTools
Revision as of 11:40, 15 December 2013 by imported>Mr. Stradivarius (start module with useful tools for dealing with Lua tables)
Documentation for this module may be created at Module:TableTools/doc
-- This module includes a number of functions that can be useful when dealing with Lua tables. local p = {} -- Define often-used variables and functions. local floor = math.floor local infinity = math.huge --[[ ----------------------------------------------------------------------------------- -- Helper functions ----------------------------------------------------------------------------------- --]] local function isPositiveInteger(num) -- Returns true if the given number is a positive integer, and false if not. if type(num) == 'number' and num >= 1 and floor(num) == num and num < infinity then return true else return false end 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 nums, ret = {}, {} for k, v in pairs(t) do if isPositiveInteger(k) then nums[#nums + 1] = k end end table.sort(nums) for _, num in ipairs(nums) do ret[#ret + 1] = t[num] end return ret end return p