bug#36566: 27.0.50; debug is sometimes horribly slow

[Lars Ingebrigtsen]

Michael Heerdegen <michael_heerdegen@web.de> writes:

> Changing `edebug-print-level' helps... Maybe the default is too
> large?

Changing it to 20 doesn't seem to have much effect, but at 10, things
are pretty speedy.  The problem then is that the output is all dots:

Result: ((((((((((... ...) (... ...)) ((... ...) (... ...))) (((... ...) (... 
...)) ((... ...) (... ...)))) ((((... ...) (... ...)) ((... ...) (... ...))) 
(((... ...) (... ...)) ((... ...) (... ...))))) (((((... ...) (... ...)) ((... 
...) (... ...))) (((... ...) (... ...)) ((... ...) (... ...)))) ((((... ...) 
(... ...)) ((... ...) (... ...))) (((... ...) (... ...)) ((... ...) (... 
...)))))) ((((((... ...) (... ...)) ((... ...) (... ...))) (((... ...) (... 
...)) ((... ...) (... ...)))) ((((... ...) (... ...)) ((... ...) (... ...))) 
(((... ...) (... ...)) ((... ...) (... ...))))) (((((... ...) (... ...)) ((... 
...) (... ...))) (((... 

It goes on like that for 6K.

I suspect that we need a better algorithm for identifying and dealing
with tree structures.  That is, if we determine that we're not really
printing a list, but a tree (that shouldn't be too difficult,
statistically), then edebug could flip a printing switch and do this...
differently.

(Hand-wavey details left as an exercise for the reader.) 

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no