Re: Add tab-tie-follow-engraver (issue2723043)

[David Kastrup]

address@hidden writes:

> OK, so now I've eliminated the triple nested loop.
>
> There is what appears to me to be a required nested loop.
>
> One loop to loop through the note-heads.
> Then an inner loop (with a break) through the ties looking for a tie on
> a note head.
> Followed by a second inner loop (with a break) through the slurs looking
> for a slur on the note head.
> Followed by a third inner loop (if we didn't find a slur) through the
> glissandos looking for a glissando on the note head.
>
> I can think of no way to simplify this code further.  If you have any
> ideas I'd be happy to hear them.

It's not a simplification, but the usual manner to find multiple
associations and deal with them is sorting.

You sort the noteheads according to some criterion, and use the same
criterion for sorting the other data structures according to their
notehead anchors.  Then you have three lists, and you work off the
notehead list, checking its current head with the other current heads,
advancing the other lists when their heads get behind, and treating the
association when the heads match.

Of course, this only makes sense when more than one list has more than
one member (more finicky, if N is the length of the largest list, the
second largest list should have significantly more than lg N members).
Otherwise, the brute-force method will tend to be faster.

-- 
David Kastrup