Re: PATH: autoload with explicit path

[Sebastian Gniazdowski <psprint2@fastmail.com>]

On Fri, Jan 27, 2017, at 08:24 AM, Peter Stephenson wrote:
> On Fri, 27 Jan 2017 07:12:59 -0800
> Sebastian Gniazdowski <psprint2@fastmail.com> wrote:
> > I do the non-fpath autoloading by local FPATH parameter. There's
> > drawback: if autoloaded function does further autoloading of other
> > function, then the earlier supplied local FPATH parameter isn't active
> > anymore.
> > 
> > So it's not possible to have /home/user/functions/{fun1,fun2}, autoload
> > fun1, and have fun2 available for fun1. Now, with the new feature,
> > directory path can be attached to function and if it calls autoload
> > itself, then the attached directory can be examined before FPATH.
> 
> You're worried about something like this?
> 
> 
> # set up function
> local path_that_only_appears_here=/foo/bar
> autoload -Uz $path_that_only_appears_here/fun1
> 
> 
> # definition of fun1
> autoload -Uz <what-goes-here?>/fun2
> fun2
> 
> 
> You can already do this using funcsourcetrace from zsh/parameter:
> ${funcsourcetrace[1]%%:<->} is the source file for the immediately
> enclosing scope, so take the directory part of that and you've
> got what you want (being careful if you happen to have evals
> or anonymous functions which generate their own scopes).

Internally via autoload it will be easy to create custom versions of
multiple functions. For example calendar does:

autoload -Uz calendar_{add,parse,read,scandate,show,lockfiles}

With the requested feature, I can copy any subset of above functions to
/home/user/functions, and "autoload -Uz /home/user/functions/calendar"
will pull them. This is also possible by prepending FPATH with
/home/user/functions, true. But deciding whether I want to pull in
custom calendar or not via FPATH management or by removing calendar*
files is hard. The new feature will be very convenient if user will have
multiple directories, for example a second one /home/user/new_functions.
To choose from where to pull in the calendar will be to simply change
path to it in autoload call.

So in .zshrc there will be:

# My custom calendar
autoload -Uz /home/user/functions/calendar

and that's it, no FPATH management or removing files from
/home/user/functions (to revert to official calendar, if the directory
is in FPATH).

> It's a bit limiting you can't get that information for any function,
> since it's alrady available internally in the shfunc structure.  I'd be
> happy to add an associative array in zsh/parameter parallel to
> $functions, say $function_sources, that gives the information for all
> functions.

Sounds nice, though it's nice that current implementation of the
absolute-path feature uses pointers to paths to limit memory usage, a
new parameter would probably spend that.

-- 
Sebastian Gniazdowski