tell if any selection changed in addition to just first region

[rchl]

Detect whenever any selection region has changed in addition to detecting whether just the first one has changed.

This is an extra functionality that is current not utilized but will be useful for #1702.

Fixes #2182

[jwortmann]

I haven't looked exactly at all changes in this PR, but I neither get any more DocumentHighlights nor code actions on this branch. So something doesn't seem right at the moment.

[jwortmann]

Is this function really necessary? Now you need to put view.sel() into the argument at all the places where it is called.
And I think you can rewrite the relevant change from this PR in a simpler way without the need to use this function

selection = view.sel()
if len(selection):
    current_first_region = selection[0]
    ...

[rchl]

And if we want to avoid calling it multiple times then i needed to change it like that. Though I'm not convinced it was necessary to optimize that in the first place

[rchl]

Note that len does a call to a native API so it would be in practice less efficient. Does it matter? Probably not.

    def __len__(self):
        return sublime_api.view_selection_size(self.view_id)

    def __getitem__(self, index):
        r = sublime_api.view_selection_get(self.view_id, index)
        if r.a == -1:
            raise IndexError()
        return r

[rchl]

Well, I figured I should test instead of guessing.

    def test_len():
        return sel[0] if len(sel) else None

    repeat = 100000
    times = timeit.repeat(test_len, repeat=3, number=repeat)
    return 'Best of {}: {} usec.'.format(repeat, min(times))

	# 0.26699970833396947 s.

    def test_trycatch():
        try:
            return sel[0]
        except Exception:
            return None

    repeat = 100000
    times = timeit.repeat(test_trycatch, repeat=3, number=repeat)
    return 'Best of {}: {} usec.'.format(repeat, min(times))

	# 0.4004749166670081 s.

So no, len variant is faster.

[rchl]

I rewrote _update_stored_selection_async in a different way and reverted first_selection_region name change and parameters.

[jfcherng]

Weird. I get different benchmark results.

import sublime
import sublime_plugin
import timeit


class ExampleCommand(sublime_plugin.TextCommand):
    def run(self, edit: sublime.Edit) -> None:
        sel = self.view.sel()
        repeat = 100000

        def test_len_1():
            return sel[0] if len(sel) else None

        def test_len_2():
            try:
                return sel[0]
            except Exception:
                return None

        def test_len_3():
            return next(iter(sel), None)

        times = timeit.repeat(test_len_1, repeat=3, number=repeat)
        print("(test_len_1) Best of {}: {} usec.".format(repeat, min(times)))
        times = timeit.repeat(test_len_2, repeat=3, number=repeat)
        print("(test_len_2) Best of {}: {} usec.".format(repeat, min(times)))
        times = timeit.repeat(test_len_3, repeat=3, number=repeat)
        print("(test_len_3) Best of {}: {} usec.".format(repeat, min(times)))

with py33 plugin-host results in

(test_len_1) Best of 100000: 0.39621629999999186 usec.
(test_len_2) Best of 100000: 0.2581017000000543 usec.
(test_len_3) Best of 100000: 0.2883709000000181 usec.

[rchl]

True. I can see the same here when using actual view.sel() rather than manually created sublime.Selection(1).

* view.sel()
(test_len_1) Best of 100000: 0.26706908333332535 usec.
(test_len_2) Best of 100000: 0.4003557916666409 usec.
(test_len_3) Best of 100000: 0.4005454583333119 usec.

* sublime.Selection(1)
(test_len_1) Best of 100000: 0.5351135833333274 usec.
(test_len_2) Best of 100000: 0.26820062500001995 usec.
(test_len_3) Best of 100000: 0.2768708750000428 usec.

[rchl]

Which seems to boil down to __len__ implementation having to do an API call and that appears to have more overhead when view ID is not valid (does not exist).

[rchl]

Any more comments on this?