Add result to @batteries

batteries/result.luau

@@ -0,0 +1,36 @@
+type T<Value> = | { success: true, value: Value } | { success: false, traceback: string, err: string }
+
+local result = {}
+
+function result.ok<Value>(value: Value): T<Value>
+	return {
+		success = true,
+		value = value,
+	}
+end
+
+function result.fail<Value>(err: string): T<Value>
+	-- Ignore the current call to debug.traceback, and the call to fail.
+	local traceback = debug.traceback(nil, 2)
+
+	return {
+		success = false,
+
+		traceback = traceback,
+		err = err,
+	}
+end
+
+function result.pcall<R, T...>(f: (T...) -> R, ...: T...): T<R>
+	local success, value = pcall(f, ...)
+
+	if success then
+		return result.ok(value)
+	else
+		local err = value :: any
+
+		return result.fail(err)
+	end
+end
+
+return result