env-dyn kind of violated the spirit of this repository---to relax and simply
have fun. While I did enjoy implementing it, there did become a point where
it got to be quite stressful and I just wanted to get it finished to move on
to other things. Hopefully others find it interesting.
Keep in mind that, as explained in the comments, this could have been
implemented much more trivially using backreferences. I chose not to do so,
since that is more of a challenge. But it may be worth creating a version
of it that _does_ use backreferences to compare against and obviate the
limitiations of finite automata.
* regex/cmp.sed: Reference `env-dyn.sed'.
* regex/env-dyn.sed:
* regex/env-fixed.sed: New scripts.
