Re: Issue 1278: Arrow notation for quarter-tones. (issue3789044)

[Carl . D . Sorensen]

This work looks good to me, but I'm not an expert in this area.

I have one question, I think.  Right now, the alteration consists of two
integers, which have implied denominators of 1/2 and 1/4, if I
understand correctly.

Would it be more general to have the alteration consist of two
rationals?  Or could we have some way of defining a base-alteration pair
that would be rationals?  And then the implied denominators of 1/2 and
1/4 would no longer be implicit, but would be explicit in either the
alteration or the base-alteration?

I think (but am not sure) that such an implementation would meet the
needs that Hans Aberg has defined for appropriate microtonal support.

Of course, this entire suggestion could be garbage, because I am not an
expert on this topic, as I mentioned above.

Thanks,

Carl



http://codereview.appspot.com/3789044/diff/29001/lily/accidental-placement.cc
File lily/accidental-placement.cc (right):

http://codereview.appspot.com/3789044/diff/29001/lily/accidental-placement.cc#newcode239
lily/accidental-placement.cc:239: Alteration last_alteration (0);
Why is this last_alteration (0), instead of last_alteration () or
last_alteration (NATURAL)?

http://codereview.appspot.com/3789044/diff/29001/lily/include/pitch.hh
File lily/include/pitch.hh (right):

http://codereview.appspot.com/3789044/diff/29001/lily/include/pitch.hh#newcode60
lily/include/pitch.hh:60: Pitch (int octave, int notename, int alt1, int
alt2);
I'm somewhat hesitant about this code that limits an alteration to two
integers.  Are we sure that this is general enough given the fact that
we're moving to an Alteration datatype?

http://codereview.appspot.com/3789044/diff/29001/lily/scale.cc
File lily/scale.cc (right):

http://codereview.appspot.com/3789044/diff/29001/lily/scale.cc#newcode36
lily/scale.cc:36: " arguments are rational numbers giving the weigth in"
spelling: weigth -> weight

http://codereview.appspot.com/3789044/diff/29001/lily/scale.cc#newcode94
lily/scale.cc:94: " scale.  The number of pitches in this scale minus
one"
"The number of scale steps in an octave is the number of pitches in the
global scale minus one."

http://codereview.appspot.com/3789044/diff/29001/python/musicexp.py
File python/musicexp.py (right):

http://codereview.appspot.com/3789044/diff/29001/python/musicexp.py#newcode308
python/musicexp.py:308: return '(ly:make-pitch %d %d \'(%d . 0))' %
(self.octave,
Why is the 0 for the second alteration hard-coded?

http://codereview.appspot.com/3789044/diff/29001/scm/define-markup-commands.scm
File scm/define-markup-commands.scm (right):

http://codereview.appspot.com/3789044/diff/29001/scm/define-markup-commands.scm#newcode2418
scm/define-markup-commands.scm:2418: (interpret-markup layout props
(markup #:musicglyph (assoc-get '(2 . 0)
standard-alteration-glyph-name-alist ""))))
Can this use SHARP, instead of (2 . 0)?

http://codereview.appspot.com/3789044/