fixed: Parser errors for new rest symbol #1091

[sss-create]

as described in #1091

the 'edge cases' resolved were:

1. the '-' could be a negative number or part of a rational number.
2. the angles and brackets tokenization from native Parsec behave weird.

puh! this was a tough one for me to find because of point 2.

Tests work, so if @yaxu gives his ok, this can be merged.

[yaxu]

I'm happy for it to be merged, but perhaps worth adding a test or two to test/Sound/Tidal/ParseTest.hs if you have time?

[sss-create]

I did. Interesting:
comparing this with itself leads to a failing test. Do I correctly use 3%4 here?
("[~~ 2 <~~ 2@7 3> 3%4 9|8 ~~ [~~ <2 9q> ~]] 2!4" :: Pattern String)

Comparing and using rationals like in the added test passes it.
edit: Checking on the current branch makes it look like this was not introduced by my changes.

[yaxu]

Hmm, well values 9q and 3%4 look like they are expecting the parser for Pattern Rational which is parsed differently to Pattern String.

So I would try changing Pattern String for Pattern Rational and see if the tests pass then.

But still, although parsing this as Pattern String would lead to difficult to anticipate results, those results should at least be deterministic, so don't know what's going on with that test..

[sss-create]

Ah yes! On both branches — with and without my changes — the test using Pattern String does fail, while the test parsed as Pattern Rational passes.

[yaxu]

Hmm, if I check out your dev branch, the tests pass, and this comparison succeeds:

(queryArc ("[-- 2 <-- 2@7 3> 1*4%2 3? 4 9|8 -- [-- <2 9q> -]] 2!4" :: Pattern String) (Arc 0 127)) == (queryArc ("[~~ 2 <~~ 2@7 3> 1*4%2 3? 4 9|8 ~~ [~~ <2 9q> ~]] 2!4" :: Pattern String) (Arc 0 127))

[yaxu]

If I run that on the main tidal dev branch, I get a syntax error from parsec, which I guess would explain the failing test?

[sss-create]

Yes, 1*3%4 works as Pattern String but 3%4 did work as Pattern Rational only. But I am not sure if there is a problem now or everything works, where it should.

[yaxu]

I think it's probably working fine!

[sss-create]

I added a test for Pattern Rational. Will merge this now :)