sage.misc.latex, sage.repl.display.fancy_repr: Make imports more local

`22f125b`	`src/sage/misc/latex.py: Move import from sage.misc.sage_eval into method`
`0809840`	`src/sage/misc/latex.py: Move import of have_program into methods`
`bdd0325`	`sage.repl.display.fancy_repr: For isinstance testing, import abc Matrix from sage.structure.element`

Answer 5 · 2021-10-06T00:47:48.000Z

comment:4

What is the rationale of moving module-level import of have_program to function level?

Answer 6 · 2021-10-06T01:54:07.000Z

comment:5

Most modules that import from sage.misc.latex only import the latex function, which does not actually need to run any program; so removing this module-level import removes the indirect dependency on sage.misc.ostools (and hence on CPython- and Unix-specific code).

Answer 7 · 2021-10-06T04:05:20.000Z

comment:6

Replying to @mkoeppe:

Most modules that import from sage.misc.latex only import the latex function, which does not actually need to run any program; so removing this module-level import removes the indirect dependency on sage.misc.ostools (and hence on CPython- and Unix-specific code).

If we need to care of these dependency issues because of the modularization effort, it might be useful to have a patchbot plugin to watch out increase of dependency among sage modules.

Answer 8 · 2021-10-06T04:05:20.000Z

Reviewer: Kwankyu Lee

Answer 9 · 2021-10-06T04:15:25.000Z

comment:7

Thanks for the review.

Yes, testing infrastructure for this is in the works - see #32432

Answer 10 · 2021-10-19T20:32:01.000Z

Changed branch from u/mkoeppe/sage_misc_latex__sage_repl_display_fancy_repr__make_imports_more_local to bdd0325