Mô đun:Array length

-- This module finds the length of an array, or of a quasi-array with keys such-- as "data1", "data2", etc., using a binary search algorithm.local checkType = require('libraryUtil').checkTypelocal function midPoint(lower, upper)	return lower + math.floor((upper - lower) / 2)endlocal function makeKey(prefix, i)	if prefix then		return prefix .. tostring(i)	else		return i	endendlocal function findLength(t, prefix, i, lower, upper)	local key = makeKey(prefix, i)	if t[key] ~= nil then		if i + 1 == upper then			return i		else			lower = i			if upper then				i = midPoint(lower, upper)				return findLength(t, prefix, i, lower, upper)			else				i = i * 2				return findLength(t, prefix, i, lower, upper)			end		end	else		upper = i		i = midPoint(lower, upper)		return findLength(t, prefix, i, lower, upper)	endendreturn function (t, prefix)	checkType('Array length', 1, t, 'table')	checkType('Array length', 2, prefix, 'string', true)	local key = makeKey(prefix, 1)	if t[key] == nil then		return 0	end	return findLength(t, prefix, 2, 1, nil)end