Stefan Monnier <monnier@IRO.UMontreal.CA> writes:

> That's right.  Or it could signal an error, if copying is considered to
> be "never the right thing to do".

If hash-tables were persistent data structures, I'd say that it would
definitely be the right thing to do.

I didn't implement map.el as a functional library because vectors and
hash-tables are not persistent.

Nico