braille: multiple consecutive whole measure rests

[mscuthbert]

What steps will reproduce the problem?

from music21 import *
p = stream.Part()
for _ in range(8):
r1 = note.Rest()
r1.duration.type='whole'
p.append(r1)
p.show('braille')

What is the expected output?

⠀⠀⠼⠙⠲⠀⠀⠀
⠼⠁⠀⠼⠓⠍⠣⠅

What do you see instead?

⠀⠀⠀⠀⠀⠀⠀⠀⠼⠙⠲⠀⠀⠀⠀⠀⠀⠀⠀⠀

⠼⠁⠀⠍⠀⠶⠀⠶⠀⠶⠀⠶⠀⠶⠀⠶⠀⠍⠣⠅

What version of the product are you using?

svn trunk

On what operating system?

Debian GNU/Linux

Please provide any additional information below.

Multiple consecutive whole measure rests can and should be transcribed
in a more concise way. Except for when we are doing bar-over-bar,
two consecutive whole measure rests should simply be written as ⠍⠍, and
more then two consecutive whole measure rests are written with a number
sign (⠼) followed by the number of rests (in our case ⠓ which means 8)
followed by the whole-rest sign (⠍).

This device is especially useful in music with several parts, or if a particular
instrument has a few measures rest. It is not possible to use in
bar-over-bar format of course, but that should not be used for a single
part like in our example above anyway.

[mscuthbert]

Will need more unit tests / doctests in segment.py before attempting. But shouldn't be too hard once the code is better known.

[mscuthbert]

I'm following the Enhancement model suggested at http://brianegranger.com/?p=249 -- closing the issue here; if others believe it is important, they can reopen the issue.