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Revision as of 12:40, 15 December 2013 by Mr. Stradivarius (talk) (start module with useful tools for dealing with Lua tables)
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-- 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