erik flister wrote:
That's what I want to do. I'm asking about a good way to write the
algorithm that traverses the notes and reconstructs the document
with the correct duration in each note.
why isn't this as simple as
Erik,
I'm learning from your code examples, but I don't understand how this
turned into an argument about simplicity. I never said it was complex. I do
admit it's probably simpler than my initial approach.
Maybe I should take a step back and describe my goals. I am experimenting
with algorithms for putting a "human touch" on midi playback. I will use
Finale to enter the music, then export as MusicXML to my software. Getting
from MusicXML---which is a complex format that encompasses everything from
notational subtleties to performance subtleties---into a relatively simple
internal representation is truly the easy part. The real meat of my project
is the code to perform the music.
foldr'ing something like this over the xml
notes (assuming monophony and that they are listed in order of start time)?
In a MusicXML document, you can't assume
- that the notes are in order of start time
- monophony
- that two tied notes are immediately adjacent in the data
None of that is true. I conceive of this problem as multiple passes. On the
first pass, I translate XML notes into a convenient internal
representation, on the second pass sort them, then make a pass to figure
out ties. Whether this is the best approach, I do not know. I am here to learn.
Regarding my use of Rational, it's because I'm representing *notated*
durations or positions in time, which are always fractions of integers.
Suppose I give the command to my program to play via midi everything from
bar 1 beat 1 to bar 2 beat 2 1/2. I want to use Rational so I know 2 1/2
means 2 1/2 and not 2.49999999999. (*) However, *performed* times are a
matter of tempo, accel, rit, trills, tremolo, arpeggio etc., and are
probably best conceived as Real.
I don't quite get this:
> forall x. (Real x, Fractional x) => x if you're picky.
Thanks,
Mike
(*) I may want to use the location of a note (bar and beat) as the key in a
Map, which I believe should be done with Rational and not Float.
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