array-like access syntax for subdivisions and alternating

[unlessgames]

Implementing #108

Subdivisons work as described in the issue. Being able to use patterns on the right side for this proved to be super handy for experimentation in my opinion, see examples in the tests.

pattrns/src/tidal/cycle/tests.rs

Lines 75 to 93 in 82bc6a6

	fn indexing() -> Result<(), String> {
	assert_cycle_equality("[a b c d]%0", "a")?;
	assert_cycle_equality("[a b c d]%1", "a")?;
	assert_cycle_equality("[a b c d]%2", "b")?;
	assert_cycle_equality("[a b c d]%3", "c")?;
	assert_cycle_equality("[a b c d]%4", "d")?;
	assert_cycle_equality("[a b c d]%5", "a")?;
	assert_cycle_equality("[a b c d]%0.1", "a")?;
	assert_cycle_equality("[a b c d]%0.25", "b")?;
	assert_cycle_equality("[a b c d]%0.499", "b")?;
	assert_cycle_equality("[a b c d]%0.5", "c")?;
	assert_cycle_equality("[a b c d]%0.999", "d")?;
	assert_cycle_equality("[a b c d]%[1 3 3]", "a c c")?;
	assert_cycle_equality("[a b c d]%[5 4 3]", "a d c")?;
	assert_cycle_equality("[a b c d]%[1, 3, 4]", "a, c, d")?;
	assert_cycle_equality("[a b c d]%<1 2 3>", "a")?;
	assert_cycle_equality("[a b c d]%<[1*8 2*4 3*2 4]>", "a*8 b*4 c*2 d")?;
	assert_cycles_equality("<a b c d>%2", &["b", "c", "d", "a"])?;

For alternating patterns <..> I went with using the index as an offset instead of a static access, so it still plays the inner steps across cycles but with an offset for where to start which seems like reasonable behaviour but there might be something better to do here, and while indexing from 1 is natural, using the same value for offsetting (ie 1 being no offset) is a bit less so.

[github-actions]

Benchmark for 8e03014

Click to view benchmark

Test	Base	PR	%
Cycle/Generate	53.0±0.48µs	52.1±0.62µs	-1.70%
Cycle/Parse	310.0±5.58µs	313.2±6.34µs	+1.03%
Rust Phrase/Clone	429.7±8.08ns	427.4±4.58ns	-0.54%
Rust Phrase/Create	66.8±1.47µs	66.8±0.85µs	0.00%
Rust Phrase/Run	639.9±6.68µs	654.2±4.15µs	+2.23%
Rust Phrase/Seek	133.5±245.59µs	146.7±256.42µs	+9.89%
Scripted Phrase/Clone	632.6±9.44ns	619.1±7.84ns	-2.13%
Scripted Phrase/Create	1006.2±12.93µs	1000.7±18.06µs	-0.55%
Scripted Phrase/Run	1664.1±15.86µs	1654.5±11.00µs	-0.58%
Scripted Phrase/Seek	224.4±451.88µs	216.2±436.93µs	-3.65%

[emuell]

Works great. And is super fun in combination with the new variables to in order to dynamically select sub sequences, too.