Re: [dev] [sandy] [PATCH] VIM key bindings.

From: Rafa Garcia Gallego <rafael.garcia.gallego_AT_gmail.com>
Date: Fri, 11 Jul 2014 09:32:10 +0200

On Fri, Jul 11, 2014 at 12:32 AM, Dimitris Papastamos <sin_AT_2f30.org> wrote:
> There are many ways to do this, I'd go for the simplest approach in terms of code
> readability and stop worrying about performance.

That. The reason sandy uses a double-linked list of lines is obviously
not performance, but code simplicity.

Sandy's performance is a joke: we memmove() the rest of the line when
typing a character, allocate new memory every 128 characters or '\n'
and memcpy() the whole file when matching a regexp. You can do worse
than that, but you have to try really hard.

Do you know what? It does not really matter. Both memory and CPU
cycles are a cheap commodity these days. Most of the time you will be
editing very small files. Unless you plan on having ed-like usability,
the UI will take most of te CPU cycles anyway. I remember a friend
came to me about editing a several megabyte XML with longish lines...
and sandy did not perform as bad as I expected. Not having multi-line
syntax highlighting (or XML highlighting) helped.


And boy, is a linked-list convenient. Implementing text manipulation
functions is a breeze. The screen painting is kinda hellish (line
wrapping takes most of the fall), but it would be worse if we had to
intertwine yet another data structure.


Don't get me wrong. We probably need another data structure in the
long run, but let's first make the editor we want and then consider
the performance implications.
Received on Fri Jul 11 2014 - 09:32:10 CEST