hg equivalent to "bk collapse"?

[Ben Hood]

> You might want to have a look at hg qimport -r and hg qdel -r, as well
> as qfold.
>
> qimport -r will convert existing hg changesets into mq patches, and
> qdel -r will convert applied mq patches into regular hg
> changesets. So, for instance, you could replace
>
> >   hg qpop -a
> >   hg import .hg/patches/144361 && hg qdelete 144361
> >   hg import .hg/patches/144342 && hg qdelete 144342
>
> with hg qdel -r qbase:qtip (or whatever revs you want to commit).
>
> If you only want one patch, you might prefer this:
>
> hg qpop 144361
> hg qfold 144342
> hg qdel -r 144361

But doesn't that nuke the history you may want to keep for your own purposes?

Sorry if this is newbie question but wouldn't it make more sense to
have the opposite of qimport to convert (non-destructively) back to an
exportable diff (e.g. qexport), or am I missing the point?