Shorthand pedal notation

Numula provides a shorthand notation for describing pedal changes over time. As with Numula's other shorthand notations, you can use iteration, substitution, and comments. This shorthand is implemented by a function sh_pedal():

from numula.notate_nuance import *

sh_pedal(s:str) -> PFT

The string consists of various components:

1/1

The pedal is off for 1 measure.

(1/1)

The pedal is on for 1 measure; the segment is open at both ends.

(.5 1/1)

The pedal is half depressed for 1 measure.

(0.2 1/1 1.0)

The pedal varies linearly from 0.2 to 1.0 over 1 measure.

The order of values and durations doesn't matter. For example, the last example could be written

(1/1 0.2 1.0)
(0.2 1.0 1/1)

In all cases, square brackets indicate closed endpoints. For example,

[1/1)

denotes a segment of pedal down, closed at the start and open at the end.

For example,

from notate_nuance import *

pft = sh_pedal('1/4 (1/8) (1/4) 4/4')

returns a PFT representing a pedal that's off for 1 beat, on for half a beat, momentarily lifted, on for 1 beat, then off for 4 beats.

You can apply this PFT as a virtual sustain pedal using

Score.vsustain_pft(
    pft: PFT,
    t0: float,
    selector: Selector = None
)

or as a MIDI pedal (soft, sostenuto, or sustain) using

Score.pedal_pft(
    pft: PFT,
    type: int = PEDAL_SUSTAIN,
    t0: float
)