Tags: patch


* Problem

Oftentimes when completing a value a user wants a small part of a
completion but not the entire thing. This happens frequently when
iterating on shell commands or on similar lines of
code. completion-preview can help with this by quickly suggesting a
sensible completion pulled from any completion-at-point function. The
problem is that accepting a full completion is often inefficient because
one might only want the first part of that completion. This leads to a
lot of deletions after the fact.

* Solution

Allow inserting of partial completions when using
completion-preview. For this I've added two new commands
completion-preview-insert-word and completion-preview-insert-sexp which
will insert the next word or sexp in the completion. For consistency
with completion-preview-insert I've refactored the code so that these
three commands share a common code path.

* Notes

 - I've added new tests for this and ensured that previous ones continue
   to pass.   
 - I've signed the copyright assignments and have contributed to emacs
   previously.

* Info

In GNU Emacs 30.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version
3.24.42, cairo version 1.18.0)
Repository revision: 988203fe980e3c80f736ad0b6aae9f288ebfa0f1
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12101013
System Description: NixOS 24.11 (Vicuna)

Configured using:
 'configure
 --prefix=/nix/store/3riplzxicrgaff4jm49wa4vvvrd6yd1l-emacs-git-20240615.0
 --disable-build-details --with-modules --with-x-toolkit=gtk3
 --with-cairo --with-xft --with-compress-install
 --with-toolkit-scroll-bars --with-native-compilation
 --without-imagemagick --with-mailutils --without-small-ja-dic
 --with-tree-sitter --with-xinput2 --with-xwidgets --with-dbus
 --with-selinux'