ENB: The os.path wrapper mess

[Edward K. Ream]

This Engineering Notebook post reviews the present state of Leo's g.os_path functions and discusses various ideas for improving them.

tl;dr: Leo's g.os_path wrappers should be deprecated, but they will remain in Leo's core.

Background

Leo's g.os_path wrappers contain redundant and confusing code, but cleaning up this mess will be dangerous. PR #3264 broke @path expressions because of an invalid rewrite of expand_path_expression. This method must not finalize the path by calling (directly or indirectly) os.path.abspath or os.path.normpath.

PR #3275 makes the minimum changes necessary to make @path work again. This PR retains all other calls to the os.path wrappers, even when redundancies are apparent.

Removing redundancy

The challenge: remove the redundancies while ensuring that Leo:

- calls os.path.expanduser and os.path wherever needed.

- never calls os.path.normpath inappropriately.

  Finalizing a path too soon can cause bugs.

Deprecating the wrappers

These wrappers are faux helpers. Leo's core can tolerate the g.os_path wrappers because they enforce standards. Plugins and scripts will likely be easier to understand if they call os.path functions directly.

Summary

Leo's core can tolerate the g.os_path wrappers because they enforce standards. I plan to deprecate these wrappers for general use.

Revising these wrappers is dangerous. The work might not become part of Leo 6.7.3.

Your comments, please.

Edward