Re: %push-* -> %define push_pull

[Paolo Bonzini]

>   %define api.push_pull "push|pull|both"
>   %define api.pure      "true||false"

Might be an idea; but what I dislike is the repetition between 
"push_pull" and the argument.  We could have "multi-word" options, like

  %define api "push pure"
  %define api "pull impure glr"
  %define api "push pull frobnicating"

which makes error checking a tad more complicated, but should be doable 
if well abstracted with m4 (and thanks to the *-skel.m4 refactoring done 
as part of the Java port).

I believe that pure/impure is a less fundamental distinction than 
push/pull, which is why I proposed something as radical as "api", but I 
see your point.

Paolo