gotcha

gotcha.lua

local function safeIndex(t, ...)
	for _,v in ipairs({...}) do
		t = t[v]
		if not t then return nil end
	end
	return t
end

local function safeIndex2(t, ...)
	local it = { ... }
	for i = 1, #it do
		t = t[it[i]]
		if not t then return nil end
	end
	return t
end

local function timeit(name, f)
	local time = ccemux and function() return ccemux.nanoTime() / 1000000000 end or os.clock
	local example = { a = { b = { c = 42 } } }
	local start = time()

	assert(f(example, 'a', 'b', 'c') == 42)

	for i = 1, 1000000 do
		f(example, 'a', 'b', 'c')
	end

	print(string.format("%s took %.1fs", name, time() - start))
end

timeit('safeIndex', safeIndex)
timeit('safeIndex2', safeIndex2)