On Tue, Jul 12, 2005 at 03:20:50AM +0000, Bart Schaefer wrote:
> it's going to cause strange behavior for anyone who already has made
> the FAQ-suggested alteration to precmd.

Yeah, but that should be a minor problem that is offset by more people
getting what they expect out of the shell by default.  I think that the
worst-case problem will be someone who needs to use the same .zshrc file
with both an older and newer zsh, but I think an easy solution for that
is to have the user tweak their .zshrc to force the new option off
(silently, in case the option isn't around) and to continue to use the
current precmd heuristic for both the old and new shells.

> I'm agnostic on whether _SPACES is the best suffix.

I'm currently thinking that the SPACES part is overly tied to the
implementation rather than what it's trying to accomplish.  How about
PROMPT_NUDGE?  That at least hints at its purpose.

> Also, it should perhaps be mutually exclusive with SINGLE_LINE_ZLE.

Perhaps, but for now I've created a trial implementation that depends on
PROMPT_CR being set (since its output would look crazy without the CR,
and anyone who has gone to the trouble to disable PROMPT_CR doesn't want
things to suddenly look wacko).  It might be better to auto-disable the
PROMPT_NUDGE option if PROMPT_CR is unset, and auto-enable PROMPT_CR if
PROMPT_NUDGE is set, but for now my code takes the easy way out and just
ignores PROMPT_NUDGE if PROMPT_CR is not set.

Attached is a patch of my first implementation.  It pays attention to
the presence of the "xn" termcap attribute to know if it should output
a full column-width of spaces (for xn terminals) or one space less (for
non-xn terminals).

..wayne..