coala is quite slow when showing version

[Makman2]

This is because coala imports every bear and then runs the version command. This shouldn't happen^^

[gitmate-bot]

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CC @sils1297, @AbdealiJK

[adtac]

Related: --help is equally slow (or just try --some-random-invalid-arg)

[sils]

@hypothesist wanna profile it? :)

[sils]

oh why do we import all bears? :/

[adtac]

@sils1297 call graph?

[adtac]

http://i.imgur.com/DIThpaY.jpg collecting bears is 50%

[sils]

HERE IS THE EVIL THING:

    inputs_group.add_argument(
        '-b', '--bears', nargs='+', metavar='NAME',
        help='names of bears to use').completer =\
        ChoicesCompleter(get_all_bears_names())

the reason why every coala invocation takes a second even if it's only showing version
it's the autocompletion!
which collects all bears...

[sils]

And here's a ChoicesCompleter that works :)

class ChoicesCompleter(object):
    """
    This class is copied and adapted from
    https://github.com/kislyuk/argcomplete.
    """
    def __init__(self, choices):
        self._choices = None

        if callable(choices):
            self._load_choices = (lambda self:
                                  setattr(self, 'choices', choices()))
        else:
            self.choices = choices

    def __call__(self, prefix, **kwargs):
        return (c for c in self.choices if c.startswith(prefix))

    @property
    def choices(self):
        if self._choices is None:
            self._load_choices(self)

        return self._choices

    @choices.setter
    def choices(self, iterable):
        """
        Initialize the choices with items from the given iterable.

        This also normalizes them to neat strings.
        """
        self._choices = []
        for choice in iterable:
            if isinstance(choice, bytes):
                choice = choice.decode(sys_encoding)
            if not isinstance(choice, str):
                choice = str(choice)
            self._choices.append(choice)

see also kislyuk/argcomplete#137 which is upstream.

[sils]

and the PR at kislyuk/argcomplete#138