Re: zsh exits after delete-char-or-list and two ^Cs

[Peter Stephenson <pws@xxxxxxx>]

(Oliver says the In-reply-to and References format should work better
like this.  Tell me if it doesn't.)

Bart Schaefer wrote:
> On Thu, 2 Sep 2004, Peter Stephenson wrote:
> 
> > It looks like it would be more sensible to have the test for whether a
> > zle widget is callable separate from the return status for zle -I.
> 
> What about zle -R ?
> 
> I think (but haven't applied it yet) that with this patch we have
> 
>   zle && echo "widgets callable"	# I'm least certain of this
>   zle -I && echo "Display invalidated and widgets callable"
>   zle -R && echo "Display refreshed and zle active"
> 
> Is that right?

Yes, noting that testing for `display invalidated' and `display
refreshed' doesn't form part of the return status (I think that's what
you mean but it's not clear from the output).

> This covers all bases, assuming it's harmless to call zle -R even when you 
> don't really care whether the display is refreshed.  Unless one might need
> to know that the display has been invalidated even when widgets are not
> callable?  I'm having a hard time coming up with that.

I agree, it's just a question of how much of a stickler you are for
having the return status reflecting `command did what I expected' rather
than `command did something and tested for something else'.  Unless
someone is using ERR_RETURN inside widgets (yuk!) I don't suppose this
is a problem.

> Sorry to nit-pick, but:
> 
> > Index: Doc/Zsh/zle.yo
> > ===================================================================
> > +The returned status is zero if a zle widget can be called immediately.
> > +Note this is independent of whether the display has been invalidated.
> > +For example, if a completion widget is active a zle widget cannot be used
> > +and the status is one even if the display was invalidated; on the other
> > +hand, the status may be zero if the display was invalidated by a previous
> > +call to `tt(zle -I)'.
> 
> Isn't it more accurate to say "the status may be nonzero even if the 
> display was invalidated by a previous call"?  With the rest of the patch 
> as it stands, the status is never zero when completion widgets are active, 
> even when the display was previously invalidated -- but the above seems to 
> imply that the status might be zero in that event.

Ah, I think I see: you're reading the two cases around the semicolon in
conjunction, while I meant them to be independent.  However, your
emendation doesn't get across quite the point I wanted, which is "if you
call zle -I and it returns zero, it may be that the display was
invalidated by a previous call rather than the current one".  Maybe
reversing the sense of the second case is better.  You might well say
"who cares", but I want to emphasis calling zle -I multiple times has no
bad effect.  Maybe the English for that is "calling zle -I multiple
times has no bad effects".

-- 
Peter Stephenson <pws@xxxxxxx>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 692070


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