Re: extending the documentation of the Scheme API

[Bengt Richter]

Hi Ricardo, Guix

On +2019-12-20 23:17:41 +0100, Ricardo Wurmus wrote:
> Hi Guix,
> 
> we have lots of nice macros and procedures in Guix that aren’t
> documented beyond their docstrings.
> 
> Should we snarf the docstrings and add them to the manual?
> 
> --
> Ricardo
> 
> 

My 2 cents, if I may:

I would _much_ rather be able to "snarf" dynamically from the command line
to stdout or -o file using appropriate parameters and options.

Even something dead simple like
gx-apropos:
--8<---------------cut here---------------start------------->8---
#!/usr/bin/bash
guile -c '(use-modules (ice-9 session))(apropos '"\"$*\""')'
--8<---------------cut here---------------end--------------->8---

quickly gets me syntax essentials for default modules.
(I have to do another variant to get this apropos to see rnrs bytevectors
or other non-default modules). Yet another variant uses oop goops describe.

I can view a manual and search it in emacs, but even so, sometimes I'd rather
insert the result of a command line invocation from within emacs.
It only takes a few seconds to grep the whole guix git repo, a bit longer for 
/gnu.

Speaking of the latter, here is an alpha kludge to do approximately what
ArchLinux's pacman -Qo does (find what package a given executable belongs to).

pacman -Qo $(which pacman)
--8<---------------cut here---------------start------------->8---
/usr/bin/pacman is owned by pacman 5.2.1-1
--8<---------------cut here---------------end--------------->8---

my gx-Qo version (takes multiple args and shows pure vs not):

gx-Qo g++ as readelf emacs lsblk less weston wayland gxQo
--8<---------------cut here---------------start------------->8---
g++:    gcc-9.1.0
as:     binutils-2.32
readelf:        binutils-2.32
emacs:  emacs-26.3
lsblk:  util-linux-2.34
less:   less-530
weston: weston-6.0.1
wayland:        (which: did not find)
gx-Qo:  (impure: '/home/bokr/bin/gx-Qo')
--8<---------------cut here---------------end--------------->8---

When I get around to it I'll add a -a option to do which -a to
report on all found. Also a -L option to report each link
(possibly a chain) leading to to the executables.

When/if I do, it will be an example of upgrading a single simple
dynamic "documentation" producer vs upgrading a document per se.

I much prefer dynamically on-the-fly-produced documentation of
the state of my system -- like /proc stuff -- it's always up to date :)
And emacs will let me escape with C-z to get to the command line
when that is convenient (or necessary if pts doesn't do some tty thing).

IMHO composing _independent_ functionalities ad-lib and powerfully
is the best gift of the bash command line.

    ...|guix hash -|...
allows me to use guix's internal default composition of sha256sum and base32,
but bash can already get at the former and IMHO it would enhance
general composability if guix's base32 were packaged as external to guix hash,
so that bash could make use of the nix encoding also, that would be a plus for 
me
e.g. maybe like
    ...|sha256sum|cut -d ' ' -f1|gx-base32|...

It's a matter of what options you have to compose functionality.
IMHO it would be good policy externalize hidden nuggets
of shell-composable functionality whenever the nuggets don't need
the package they come in to function.

I think this should be viewed at the system architecture level
so that the natural Chauvinism of an exciting project does not
in effect create a walled garden that prohibits[1] cloning a
simple (with simple system abi dependencies) internal wheel barrow 
for use at home.

[1]I know "prohibits" does not apply to extracting nuggets
from FOSS, but the effort can be prohibitive, where the original
developers of the nugget could have made it easy in many cases :-/

HTH in some way :)

-- 
Regards,
Bengt Richter