Re: Overlay insertion types, markers, etc.

[Stefan Monnier]

> 4. Can you retrieve the markers that are "used by"
>    an overlay, i.e., as markers?

No, you can't, and you shouldn't be able to: it's an implementation
detail, that may change in the future (IIUC the `noverlays` branch
indeed makes this change as part of a rewrite which tries to eliminate
some algorithmic complexity problems in the overlay code).

Also it would introduce all kinds of extra work:
- when an overlay is moved, the redisplay code is told about it, whereas
  no redisplay is normally caused by moving a marker, so we'd need to
  figure out what to do when an "overlay-owned" marker is moved.
- the user could now move the start-marker of an overlay to another buffer
  than the end-marker
- the user could now move the end-marker of an overlay before the
  start-marker (this can already happen but only in very specific
  cases, so we'd have to handle it in more cases).
- ...


        Stefan