Takashi Kato scripsit:

> 1. It can not be a base of whole Scheme types (correct me if I'm wrong)

I think it can, since if you don't have access to the raw procedures,
you can only do things through the provided interface.  You'd still need
something to represent a low-level multiplicity of objects, an n-tuple of
some sort.

> 2. There's no way to retrieve parent payload value by parent accessor.

If you mean the type payload, that is true and intentional.

I will include in the next draft the ability for a parent accessor
to retrieve the instance payload from an instance of a subtypes.

> 3. It seems this SRFI is created because SRFI-136 can't be implemented
>    without keeping compatibility of other record types.

In fact I have had it in mind for a long time, but I decided not to publish
it, because the SRFI 99 (possibly with SRFI 131) approach seemed to be
well accepted.  But now that the door is open ....

--
John Cowan          http://www.ccil.org/~cowan        xxxxxx@ccil.org
If a traveler were informed that such a man [as Lord John Russell] was
leader of the House of Commons, he may well begin to comprehend how the
Egyptians worshiped an insect.  --Benjamin Disraeli