Clean up and centralize "path access" functionality.

[thorwhalen]

There are many "path access" functionalities out there, under different names and forms.

We really should clean this up and settle on one general mini-framework for this purpose.

Just to start with one: path_get is one that I'm about to deprecate since _path_get seems to be at a better level of generality.

There’s also a version of path_get (same exact name) in s3dol

I see even two more (very simple ones) in other projects.
And that’s just those matching the NAME path_get .
I’m sure there’s 2 to 3 times more of them with different names.

dol doesn’t even use that path_get function.
Not even in its add_path_get or add_path_access in dol.trans. Instead, it just inlines the functionality with reduce: See here

Note: We talked about path_get here, but this just represents the read concern. We also should address the write and delete concerns (which add_path_access does, as a store decorator).

More related stuff

• path_set
• path_extractor
  • More general use of callables in path_extractor path elements
• Enabling (optional) KeyPath ability to write when path doesn't already exist
• kv_walk: docs, tests, tools, and recipes
• Making conditional_data_trans better, and generally; recursively applying wrappers

[thorwhalen]

In s3dol: Use dol's path_get instead of own