#378: User-specified path for load and attach
------------------------------+---------------------------------------------
Reporter: was | Owner: was
Type: enhancement | Status: needs_work
Priority: major | Milestone: sage-4.6.1
Component: user interface | Keywords:
Author: Mitesh Patel | Upstream: N/A
Reviewer: | Merged:
Work_issues: |
------------------------------+---------------------------------------------
Comment(by flawrence):
Replying to [comment:10 timdumol]:
> Things work perfectly, but I think it might be better to follow the
Python stdlib in exposing the array itself, instead of covering it in a
function (`sys.path` instead of `sys.path()`, so similarly,
`load_attach_path` instead of `load_attach_path()`). Also, it might be
handy to `os.path.expand_user` any paths handed to the function, so you
could have load_attach_path.append("~/foo"). What do you think?
I've had a bit of a hack at exposing the array itself, but there are
problems making it sufficiently global. `sys.path` works for the stdlib
because `path` is a variable in the `sys` module. The logical thing to do
here is to create a `load_attach_path` variable in the preparser module,
but following the stdlib analogy this would require the user to edit
`sage.misc.preparser.load_attach_path`, which is not very user friendly.
Failing this, it looks like the best you can do is a `from
sage.misc.preparser import load_attach_path`, but this is a fragile state
of affairs: if you reassign `load_attach_path` anywhere, either from
sage's command line or by calling some function like
`sage.misc.preparser.reset_load_attach_path()`, you end up with a
situation where `load_attach_path` and
`sage.misc.preparser.load_attach_path` are different objects.
This requires caution on the part of the user and the programmer. For
example, `reset_load_attach_path()` can't include
{{{
load_attach_path = ['.']
}}}
instead it has to do
{{{
while load_attach_path != []:
load_attach_path.pop()
load_attach_path.append('.')
}}}
If the user accidentally reassigns `load_attach_path` in the command line,
they'll have to re-run `from sage.misc.preparser import load_attach_path`.
I don't think that this step can be included in a
`reset_load_attach_path()` function due to the different scopes.
So it's possible to expose the `load_attach_path` array to the user, and
I've written most of a patch that does this, but there's lots of things
that could go wrong so I'd suggest sticking to the existing patch's
approach of hiding behind a function. If others think that the pros
outweigh the cons then I'll tidy up the patch and upload it.
Thoughts?
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/378#comment:16>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en.
