Learn English – How to concisely handle words that don’t have an antonym

I work in software for a living, and have had a problem recently with the language I use to describe software components. This profession increasingly reveals itself to need the skill to accurately and concisely describe something. My problem is thus: Often I create actors that do something, and other actors that undo something, but I cannot simply invert the words I describe the former with to describe the latter. I need words to name "the thing that undoes".

To use a recent example: the word "wrapper". A quick search in the internet reveals that wrapper is a word, and has a listing of synonyms… but there are no antonyms. Similarly, I tried enveloper and packer, expecting at least "unpacker" to be a word, alas it is not. I haven't done an exhaustive search, yet there seems to be a pattern of words of this form not having an opposite.

Ignoring the legality of the words and using "unwrapper" is a possibility, but spellcheck is going to complain. Maintaining exclusion rules also seems rather… tiresome.

I'd also like to avoid having to use too many words to describe things that undo something. I could have a pair such as "wrapper" and "wrappedcontentremover", but that is mighty inelegant.

For clarity's sake, I mean "one who wraps" and not "material used to coat".

Is there a way to handle this in a legal and concise way?