Express "put this processor at flat index to" as the PLACEMENT that produces it — the one
translation a drag-and-drop surface needs, and the only way an index-shaped request reaches
the model now.
The destination POINT is the point of whatever currently occupies to once the moved node
is out of the way; the destination SORT is the midpoint between its new neighbours inside
that point (see sortBetween), so nothing else is renumbered. A pinned processor does
not move: its point is the skeleton's, and this returns the chain unchanged rather than
pretending otherwise — the caller sees no move, which is the honest answer.
Express "put this processor at flat index
to" as the PLACEMENT that produces it — the one translation a drag-and-drop surface needs, and the only way an index-shaped request reaches the model now.The destination POINT is the point of whatever currently occupies
toonce the moved node is out of the way; the destination SORT is the midpoint between its new neighbours inside that point (see sortBetween), so nothing else is renumbered. A pinned processor does not move: its point is the skeleton's, and this returns the chain unchanged rather than pretending otherwise — the caller sees no move, which is the honest answer.