Re: Managing environments (Python venv, guix environment, etc.)

[sbaugh@catern.com]

Eli Zaretskii <eliz@gnu.org> writes:
> It may seem to you that remote access is similar to a different
> environment, but in fact they are very different.  Environment is not
> a property of a file name, it is a property of a project.

Environment is not a property of a project either, it's something else
entirely. A project doesn't necessarily have an environment associated
with it, and an environment isn't necessarily asociated with a
project. Treating it as a property of a file name or a property of a
project are just two possible interfaces/implementations; both will
limit the user.

Remote access was turned into a property of a file name by embedding the
remote host identifier into the file name. If we embed the environment
into the file name, then the environment also becomes a property of a
file name.

> Moreover, past attempts I know about to use file handlers for
> processing local files turned out to have subtle misfeatures.

I would be interested to see previous failed attempts to use file
handlers on local files, can you point me to an example?

AFAIK jka-compr.el works fine.

> Even more importantly, the _conceptual_ difference is huge, and it's
> bound to bite us in the long run, because people who work on the
> file-name handlers has the remote-access concept on their mind, and
> will write code that caters to those use cases, so we will sooner or
> later end up with code that subtly breaks in the environment use
> cases.

That is a very fair point, but I think the current state of file-name
handlers is functional for the environment use-case. And so if it works
out, not breaking environment.el can be considered in future
modifications to file-name handlers.

Anyway, isn't the file-name handler interface a generic way to abstract
over access to the underlying operating system, not just a method for
implementing remote-access? Wouldn't a change that caused file-name
handlers to be only usable for remote acces, be a bug?