Requested changes to R4RS

[Chris Hanson <cph@kleph.ai.mit.edu>]

The following is a list of changes to the R4RS, which are being
requested by the IEEE Working Group on Scheme.  It would be
appreciated if the changes could be implemented, or appropriate
comments generated, in time for the July 7 meeting of the Working
Group.

I'm not sure how such things can be decided over the net, but given
that these changes are believed to be non-controversial, perhaps we
could take an informal vote after suitable discussion.


* We request that `list-ref' and `list-tail' have their status changed
from inessential to essential.

* We believe that `peek-char' is underspecified and request that the
specification be improved.  [Does anyone remember the arguments?  It's
possible that the added note in R3.95RS is sufficient -- cph]

* We suggest that `integer->char' and `char->integer' should be
constrained more carefully.  In particular, the order isomorphism
requirement seems excessively strong; perhaps a one-to-one map
requirement would be more appropriate.

* We request deleting the "alphabetic" restriction on the domains of
`char-upper-case?' and `char-lower-case?' (extending these domains to
all characters), defining the procedures to return #F for
non-alphabetic characters.