Kieren MacMillan <kie...@kierenmacmillan.info> writes: > Hi David, > >> No. You propose replacing (cons 3 4) as a time signature designation >> with (cons 3 (ly:make-duration 2)). You have failed to give any >> indication of what you want to see (cons 8 20) replaced with. > > Well at least now you’ve asked the question you clearly meant to ask > earlier, in a way that someone other than you can figure out how to > answer in the way you’re expecting. =) > >> It will likely end up as (ly:make-duration 4 0 4/5) > > That seems fine to me. > >> but that has no unique printed representation different from >> (ly:make-duration 4) > > Correction: Lilypond doesn’t, by default, give a “unique printed > representation” to (ly:make-duration 4 0 4/5) as compared with > (ly:make-duration 4). On the other hand, I am fully capable of making > Lilypond do so, i.e., formatting the denominator as a sixteenth note > *with a '5' [possibly in a bracket] below it*, which absolutely *is* a > “unique printed representation”, and will convey to the performer > exactly the desired meaning. > >> (ly:make-duration 4 0 4/5) and (ly:make-duration 4 0 8/10) >> are absolutely indistinguishable. > > I can do the math to back-calc either of those into a note duration in > order to determine.
There is no either of those. They are identical. You cannot distinguish a 5-tuplet from a 10-tuplet in that representation. > So I guess here’s my [final] answer to your question: I’d like to see > (cons 8 20) replaced with whatever is easiest for the lexer / parser > to convert to and from and/or pass through to the time function(s) > without losing any critical information about the denominator > duration. You are just evading the question. The problem is that there is no unique representation as a LilyPond duration for print forms representing 1/20th of a whole note, and you and Carl are glossing over the fact that the time signature 8/20 does not actually specify such a duration but does, contrary to your theories, indicates 1/20 of a whole note as the unit without specifying _how_ this unit is actually musically established in terms of durations. > Feel free to ask me for yet another answer to this question… but be > warned that I don’t know enough about the lexer or parser or > Lilypond’s internal representation of durations to give a more > specific or nuanced or helpful answer than that. ;) The problem is that handwaving looks great in discussions but does not deliver a definition useful for implementation. -- David Kastrup
