Suffice it to say that you won't be writing elaborate software in a game world that was never meant for it. Code is inherently slow due to Minecraft's 20Hz operation clock (you can never perform more than 20 commands per second), and it bogs down the more you use it. However, you won't have to spend weeks recreating the interpreter yourself -- SethBling has posted the necessary material, so it's just a matter of installing the add-on and brushing up on your IF/THEN statements.