Ultra slow lua solution (aka as slow as my naive rust solution)

src/main/lua/main.lua

@@ -0,0 +1,57 @@
+local file_path = "../../../measurements.txt"
+
+local file = io.open(file_path, "rb")
+if not file then
+	print("Unable to open file")
+	return
+end
+
+local function split_semi(inputstr)
+	local t = {}
+	for str in string.gmatch(inputstr, "([^;]+)") do
+		table.insert(t, str)
+	end
+	return t
+end
+
+local stations = {}
+
+local iterations = 1
+
+for line in file:lines("*l") do
+	if iterations % 1000000 == 0 then
+		io.write("\x1b[J\x1b[H")
+		io.write(iterations / 10000000)
+		io.write("\n")
+	end
+	local split_line = split_semi(line)
+	local station = split_line[1]
+	local temp_str = string.gsub(split_line[2], "[ ]", "")
+	local temp = tonumber(temp_str)
+	if stations[station] == nil then
+		stations[station] = { min = temp, max = temp, sum = temp, count = 1 }
+	else
+		if temp < stations[station].min then
+			stations[station].min = temp
+		elseif temp > stations[station].max then
+			stations[station].max = temp
+		end
+		stations[station].sum = stations[station].sum + temp
+		stations[station].count = stations[station].count + 1
+	end
+	iterations = iterations + 1
+end
+
+local keys = {}
+for k in pairs(stations) do table.insert(keys, k) end
+table.sort(keys)
+
+local fstations = {}
+io.write("{")
+for _, station in ipairs(keys) do
+	local avg = ((stations[station].sum / 10) / stations[station].count)
+	local res_str = string.format("%s=%.1f/%.1f/%.1f", station, stations[station].min, avg, stations[station].max)
+	table.insert(fstations, res_str)
+end
+io.write(table.concat(fstations, ","))
+print("}")