[vinceguidry]

You need a compiler when you need language, that is, when you need to interface directly between brain and computer. Everything else can be less messily-specified. A good middle ground is the DSL, domain-specific language. You use the syntax and semantics of the language being used to code in, and change the nouns and verbs. All the nouns and verbs are given meaning as values or functions. Execute in a sandbox so that your DSL can't find the rest of the language. Ruby makes this all trivial.

Of course, if you're trapped in a static language with no way to execute significant logic at runtime without a ton of heavy lifting, then yeah, you'll end up maintaining an interpreter / compiler if you're not careful. Really do yourself a favor and see if you can't introduce Ruby, you can adapt it to your needs. You can inherit from BasicObject, BasicObjects can't see anything you don't want them to see.