This has the adventage that "meson --help" shows a list of all commands,
making them discoverable. This also reduce the manual parsing of
arguments to the strict minimum needed for backward compatibility.
Fixed manually promoting wrap files with a full path, e.g.
`meson wrap promote subprojects/s1/subprojects/projname.wrap`,
which resulted in an error before (new test added:
`./run_unittests.py AllPlatformTests.test_subproject_promotion_wrap`).
Additionally, running promote with an invalid subproject path now fails
properly. Before, it just silently did nothing (added to test:
`./run_unittests.py AllPlatformTests.test_subproject_promotion`).
According to Python documentation[1] dirname and basename
are defined as follows:
os.path.dirname() = os.path.split()[0]
os.path.basename() = os.path.split()[1]
For the purpose of better readability split() is replaced
by appropriate function if only one part of returned tuple
is used.
[1]: https://docs.python.org/3/library/os.path.html#os.path.split
Meson has a common pattern of using 'if len(foo) == 0:' or
'if len(foo) != 0:', however, this is a common anti-pattern in python.
Instead tests for emptiness/non-emptiness should be done with a simple
'if foo:' or 'if not foo:'
Consider the following:
>>> import timeit
>>> timeit.timeit('if len([]) == 0: pass')
0.10730923599840025
>>> timeit.timeit('if not []: pass')
0.030033907998586074
>>> timeit.timeit('if len(['a', 'b', 'c', 'd']) == 0: pass')
0.1154778649979562
>>> timeit.timeit("if not ['a', 'b', 'c', 'd']: pass")
0.08259823200205574
>>> timeit.timeit('if len("") == 0: pass')
0.089759664999292
>>> timeit.timeit('if not "": pass')
0.02340641999762738
>>> timeit.timeit('if len("foo") == 0: pass')
0.08848102600313723
>>> timeit.timeit('if not "foo": pass')
0.04032287199879647
And for the one additional case of 'if len(foo.strip()) == 0', which can
be replaced with 'if not foo.isspace()'
>>> timeit.timeit('if len(" ".strip()) == 0: pass')
0.15294511600222904
>>> timeit.timeit('if " ".isspace(): pass')
0.09413968399894657
>>> timeit.timeit('if len(" abc".strip()) == 0: pass')
0.2023209120015963
>>> timeit.timeit('if " abc".isspace(): pass')
0.09571301700270851
In other words, it's always a win to not use len(), when you don't
actually want to check the length.
Xavier Claessens
Daniel Pirch
Aleksey Filippov
Jussi Pakkanen
Dylan Baker
Mike Sinkovsky
Igor Gnatenko
Elliott Sales de Andrade