#22 pop the history

[ggrothendieck]

Ability to pop the last N commands off the history
in server mode so that one can do behind-the-scenes
commands without messing up %.

For example, one might want to query and set the
prettyprinter.

---

Comment by matmota:

Logged In: YES
user_id=78635

You can accomplish that by putting the actions in a list,
between square brackets "[]".
For example:

In> [x:=2+3; Sin(0.5); 3-4;]
Out> -1
In> %
Out> -1
In>

As you see, the value of the composite expression you put
into brackets is the value of the last item. That's exactly
what I did a couple of years ago when communicating with
Yacas via pipes, before I wrote the OMREP() function, so
that I got as response the value of evaluating some
expression, and not the previous steps such as setting the
pretty-printer to OMForm, as you want to do.

---

Moved from SF: 1292775