Re: address@hidden: Speed of all-completions]

[David Kastrup]

Andreas Schwab <address@hidden> writes:

> David Kastrup <address@hidden> writes:
> 
> > Andreas Schwab <address@hidden> writes:
> >
> >> David Kastrup <address@hidden> writes:
> >> 
> >> > Andreas Schwab <address@hidden> writes:
> >> >
> >> >> This is due to this change:
> >> >> 
> >> >>         (Ftry_completion, Fall_completions, Ftest_completion): Bind
> >> >>         case-fold-search to the value of completion-ignore-case when
> >> >>         checking completion-regexp-list.
> >> >> 
> >> >> I've checked in a fix that avoids the overhead of specbind when
> >> >> completion-regexp-list is empty.
> >> >
> >> > At the cost of being more expensive when it isn't.
> >> 
> >> Why is it more expensive?  The check for CONSP (completion-regexp-list)
> >> has to be done anyway, and can be CSE'd by the compiler.
> >
> > Because you are redoing the binding for every element in the loop,
> > while it is needed only once.
> 
> I did not change anything in this regard.

Serves me right from just looking at the result instead of what you
started with.

To illustrate what I mean, here is a patch against the most recent
version.  Note that I have to undo the binding before calling a
user-defined predicate function (which might rely on the original
binding).  The last of your three changes, not running in a loop, was
not improvable, however.

txtQydVHZiUZr.txt
Description: Text Data

Does this look sane enough?

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum