Override theme function inside module, template_preprocess_field I'd like to implement template_preprocess_field in a module for organizational purposes.

How can I do this?

Thanks!

Reference:
https://api.drupal.org/api/drupal/core%21includes%21theme.inc/function/template_preprocess_field/8.2.x
Hook functions are named like so: MODULENAME_hook.

In your case that's:

function MODULENAME_preprocess_field(&amp;$variables) {

}