Re: `make-overlay' very slow

[Stefan Monnier]

> and I found out that it is, alas, unusable.  It starts with about 1000
> replacements per second on my GNU/Linux box (using simply `-' as the
> regexp), but soon the speed decreases: After approx. 10000
> replacements it only can handle 100 replacements per second -- the
> attached code now contains a small counter to show the progress.  If
> you comment out the call to `make-overlay', the code really flies...

> Am I doing something wrong?

overlays have a poor algorithmic behavior (many operations take a time
proportional to the number of overlays in the buffer).  Better use
text-properties (which are implemented with a tree and should provide
something closer to O(log N) complexity instead).


        Stefan