Can we get rid of all calls to `eval`?

[davidanthoff]

There are a few cases in the code base where we call eval. Can we get rid of them? Some of these happen in macros, and I would think there in particular we should be able to avoid that?

[rjplevin]

It would be good to discuss this. I've tried to eliminate the use of eval, but there are some cases I wasn't able to resolve easily.

[rjplevin]

The only remaining eval calls evaluate default parameter values set in @defcomp. I think this is ok.