[R6RS] 3 things we may want to vote on

dyb at cs.indiana.edu dyb
Tue Jun 7 15:03:45 EDT 2005

> - Make continuations created by BEGIN accept multiple values?

I am certainly ready to vote ('yes') on this.

> http://mailman.iro.umontreal.ca/mailman/private/r6rs/2004-October/000267.html
> Two decisions, actually, the second one on specifying primitives to
> return zero values.

I'm not sure about this.  It might be preferable for the number of values
and actual values of an expression or primitive with no useful values
be unspecified.  Returning a single value may be less expensive in some
implementations than returning zero values.

> - Zap SET-CAR! & SET-CDR! ?

I'm not sure about this either.

> - Make -> a valid identifier?

> Two decisions on this issue as well: Whether to make -> a valid
> identifier (for which a lot of people at the last Scheme workshop
> voted), and, if so, how to do it.

I am in favor of generalizing the set of identifiers to include more
that begin with -, like -> but also others.  I believe that the grammar
you give in

> http://mailman.iro.umontreal.ca/mailman/private/r6rs/2004-October/000302.html

which is

> <peculiar identifier> -> + | - | ... | <dash identifier>
> <dash identifier> -> - <dash subsequent> <subsequent>*
> <dash subsequent> -> <initial> | <special subsequent>

has a problem, however, in that -i becomes a valid identifier even though
it is already a valid number.  So we'd need to fix this somehow.  We'll
also need to watch out for our printed representations of IEEE positive
and negative infinities.  I would also like similar generalizations for
identifiers starting with '.' and '+'.


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