Re: amd@gnu.org: eshell and external commands

[John Wiegley <johnw@newartisans.com>]

Chong Yidong <cyd@stupidchicken.com> writes:

> I thought so at first, but after trying out, I don't notice any observable
> slowdown for using eshell-eval-command for the eshell/* lisp commands.

This is likely due to the speed of your machine.  When I was using my old
Pentium III laptop, the slowdown was so exaggerated that I finally sought the
cause -- which resulted in this fix.

> I don't know how to hack the code to implement the deferment behavior for
> "fallback to external programs" commands.  Do you have an idea how to do it?

You know, something you could do is to traverse the Lisp tree at the point of
decision looking for the symbol `eshell-external-command'.  If it's found, use
eshell-eval-command rather than eval.  That way, the slowdown is only suffered
for external commands, which are going to be slow anyway because of the
necessary invocation of an external process.

John