[webkit-dev] Canonical positions

[Alexey Proskuryakov]

  It looks like WebKit HTML editing code has several concepts of a
"canonical" position:

 - Positions are not automatically canonicalized, but Position.isCandidate()
and PositionIterator.isCandidate() pick out some of them as better ones.

 - VisiblePositions are automatically canonicalized with
VisiblePosition::canonicalPosition(). A Position that corresponds to a
VisiblePosition is called deepEquivalent.

 - To be used in ranges, Positions have to be canonicalized with
rangeCompliantEquivalent(). Even VisiblePositions are not directly suitable
for use in ranges.

  Can the differences between these be explained in some high-level fashion?
So far, I haven't had much luck with understanding them from reading the
code.

- WBR, Alexey Proskuryakov.