Re: xterm.el

[Dan Nicolaescu]

Stefan Monnier <address@hidden> writes:

  > >>>>> "Nick" == Nick Roberts <address@hidden> writes:
  > 
  > > xterm.el makes Emacs take about seven times as long to load for me (about 
14
  > > seconds on my 200MHz PC). I have tested this by setting term-file-prefix 
to
  > > nil as described in startup.el
  > 
  > > I think this is due to the recent changes in xterm.el e.g
  > > substitute-key-definition is invoked 48 times.
  > 
  > We could speed this up significantly by doing a single traversal of the
  > keymap, doing the 48 substitutions simultaneously.
  > The patch below defines a new function substitute-key-definitions which
  > xterm.el could use to good advantage.
  > The interest of this new function is that it is a *simultaneous*
  > substitution, so it can be used to swap FOO and BAR, whereas doing it with
  > substitute-key-definition requires substituting TOTO for FOO, than FOO for
  > BAR and then BAR for TOTO.

When using substitute-key-definitions in xterm.el, the load time for
xterm.elc is reduced from 0.3 seconds to 0.13 seconds on a 500MHz
P3. (This is with substitute-key-definitions being called before all
the define-key calls).

I'll patch xterm.el accordingly if substitute-key-definitions is
committed.

                --dan