Re: completion tricks

[Adam Spiers <adam@xxxxxxxxxx>]

Sven Wischnowsky (wischnow@xxxxxxxxxxxxxxxxxxxxxxx) wrote:
> On a stand-alone Linux box there probably really isn't that much
> difference, but at least for me compiling the whole completion system
> into a memory mapped digest file and using that makes things faster
> (after the first function is loaded).  It also saves memory, of course 
> because mapped files are shared by all instances of zsh running on the 
> same host (if your OS supports that, but almost every Unix should).

Would you mind showing how you do this quickly?  I tried:

  $ zcompile ~/.zsh/comp.zwc ~/local/share/zsh/4.0.1-pre-2/functions/Completion/*/_*

ripped from the example usage of zrecompile, but I got:

zsh: parse error near `|'
zcompile: can't read file: /nfs-home/adams/local/share/zsh/4.0.1-pre-2/functions/Completion/Builtins/_vars_eq

This is with the latest CVS.

Also, for this to work, wouldn't I have to include ~/.zsh/comp.zwc in
fpath?  Why did the example suggest only to compile Completion/*/_*,
not Completion/*/* ?

I get the impression there are several different strategies one could
take with compilation.  For example, how much is there to be gained by
replacing all the Completion/* directories from the fpath with a
single compiled foo.zwc digest?  Could you even do that, given that
presumably foo.zwc would be missing Completion/Core/comp* ?

The more I think about it, the more I like the idea of `make install'
(or maybe `make install.zwc') taking the most sensible compilation
route.  The distribution's completion functions probably aren't going
to change at all in between upgrades, after all.

> > Completing files with TAB was noticeably slower with the new
> > system over the old.
> 
> As Adam pointed out, this of course depends on the completers one uses 
> (and the match specs, btw.).

Perhaps these performance hits should be mentioned in the manual?

> Anyway.  I can't and wouldn't want to force anyone to switch to the
> new system -- but you miss a lot ;-)

You certainly do :-)