A super simple benchmark function in Lua

bench.lua

---Run a benchmark
---@param fn function
---@param outer_iter integer?
---@param inner_iter integer?
---@param warmup_iter integer?
local function bench(fn, outer_iter, inner_iter, warmup_iter)
	outer_iter = outer_iter or 100
	inner_iter = inner_iter or 10000
	warmup_iter = warmup_iter or 10

	for i = 1, warmup_iter do
		fn()
	end

	local times = {} ---@type number[]
	local times_pos = 1
	for i = 1, outer_iter do
		local from = os.clock()
		for j = 1, inner_iter do
			fn()
		end
		local to = os.clock()

		times[times_pos] = to - from
		times_pos = times_pos + 1
	end

	local sum = 0
	for i = 1, #times do
		sum = sum + times[i]
	end

	print('average seconds:', sum / #times)
end