'fontTools' is not a folder name, but the import name of the package
where we have some doctests to be discovered and run.
even though we have --pyargs option (which makes pytest first attempt
to treat any positional arguments as module import names), with the
latest pytest 4.0.0 our tests started to fail as if the new pytest
is evaluating the default 'testpaths' (as defined in setup.cfg, used
when no arguments are supplied to pytest) _before_ the --pyargs
option, and thus it thinks that 'fontTools' is a directory name
instead of a package name...
This a workaround. It also means that if one runs `pytest` without
arguments, only the tests inside `Tests` directory are going to be
run automatically, and not also the doctests inside fontTools package.
When running the test suite using tox, all tests are run, both
those in Tests folder and the doctests in fontTools.
See 0283b1f.
By finishing overlayBox() to cull remainder box when possible, we generate
far fewer spurious boxes, if any.
For the featureVars_test.py test case, this now generates optimal output,
that is, 2*n - 1 boxes.
Running time for n=20 stays at 0.06s, which is probably Python startup
time.
Running time for n=100 is down from 2.5s with unoptimized new algorithm,
to 0.17s for this and number of output boxes from 5050 to the optimal 199.
Fixes#1372 again
Whereas previous algorithm had exponential running time and return
value size, new one has quadratic.
For featureVars_test.py test case, for example, which is a pathological
test case of n sliding intervals, the number of output intervals of
various algorithms are:
- Previous algorithm: 2**n - 1
- New algorithm: n*(n-1)/2
- Optimal algorithm: 2*n - 1
Ie, we go from exponential to quadratic, whereas in this case the optimal
solution is linear.
Running time of said test, for n=20, goes from over 20s, to 0.06s.
The algorithm can be improved. The overlayBox() function currently does
not try to shrink the remainder box. Doing that will probably bring us
to optimal solution for this test case.
Fixes https://github.com/fonttools/fonttools/pull/1372
One test is failing. Needs to be investigated that new output is correct,
and test expectations updated.
