Finding the file offsets for functions

Finding the file offsets for functions

[Zach Riggle]

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So I've recently been poking around with the goal of finding the filename,
and line-range where a function is actually declared.  The intent is to
have the function equivalent of "vim =command", but to also include the
relevant file numbers

The "whence" builtin, specifically "-v" and "-w" flags, are very useful for
deciding if something is a command, function, autoloadable function,
builtin, or alias.

In the "command" case, our work is done.

For functions, things get more complicated.

$ whence -v abcd
abcd is a shell function from
/Users/zachriggle/.zprezto/modules/zach-riggle/alias.zsh


Autoloadable functions show up differently.

$ whence -v zztop
zztop is an autoload shell function


We can force-load these to determine their locations

$ whence -v zztop
zztop is an autoload shell function

$ zztop
Zztop module loaded

$ echo $functions_source[zztop]
/Users/zachriggle/.zprezto/modules/zach-riggle/functions/zztop

$ whence -v zztop
zztop is a shell function from
/Users/zachriggle/.zprezto/modules/zach-riggle/functions/zztop

$ zztop
This is zztop

$ declare -f zztop
zztop () {
echo This is zztop
}

$ cat /Users/zachriggle/.zprezto/modules/zach-riggle/functions/zztop
#!/usr/bin/env zsh#
zztop() {
    echo This is zztop
}
echo Zztop module loaded


So now we can find the source file which contains a function ($functions or
whence -v), and can work with autoloadable functions to get them loaded.

The state I'm at now is finding the first / last line for a given function,
in the file it is declared in.  In the case of autoloadable functions,
where no function need be declared (the whole body is the function) we have
a convenient null solution.

I can also get the source code to the function, via e.g. "declare -f".
This is reformatted from its original form, which is generally fine.

I've run into issues where I'd like to create a
path/to/autoloadable:$lineno such that I can easily pass it to vim or
another editor.  This saves a lot of time on my end


*Zach Riggle*

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Re: Finding the file offsets for functions

[Bart Schaefer]

On Fri, May 20, 2022 at 11:27 PM Zach Riggle <zachriggle@gmail.com> wrote:
>
> Autoloadable functions show up differently.
>
> $ whence -v zztop
> zztop is an autoload shell function

In recent zsh you can use
  autoload -r zztop
and then whence -v output and $functions_source will include the path
(but you also can't change that path later by changing $fpath).

> $ cat /Users/zachriggle/.zprezto/modules/zach-riggle/functions/zztop
> #!/usr/bin/env zsh#
> zztop() {
>     echo This is zztop
> }
> echo Zztop module loaded

That pretty much obliterates the whole reason for "autoload".

If you don't like "autoload -r" at the time of declaring all the
autoloads, you can use "autoload +X" at the time you want the source
of a particular function.

     The flag +X attempts to load each NAME as an autoloaded function,
     but does _not_ execute it. ...
     ... This does _not_ replace any existing definition ...

> I've run into issues where I'd like to create a path/to/autoloadable:$lineno such that I can easily pass it to vim or another editor.  This saves a lot of time on my end

Wouldn't
  vim "+/function $name\\|$name *()" $functions_source[$name]
be sufficient in nearly all cases?

Re: Finding the file offsets for functions

[Bart Schaefer]

On Sat, May 21, 2022 at 1:17 PM Bart Schaefer <schaefer@brasslantern.com> wrote:
>
> Wouldn't
>   vim "+/function $name\\|$name *()" $functions_source[$name]
> be sufficient in nearly all cases?

If you actually need the line number instead of +/, try:

lineno=${"$(grep -n "function $name\\|$name *()" $functions_source[$name])"%:*}