On 11-Apr-06, at 5:51 PM, Taylor R. Campbell wrote:

> I'm posting this merely for the sake of offering another opinion on
> legibility; I don't think that any syntax changes in this area are
> good, because they can break existing and compliant R5RS code.  For
> instance, I've seen this naming convention somewhere: FOO has to do
> with an exclusive interval, FOO: with an interval exclusive on the
> lower bound and exclusive on the upper bound, :FOO with an interval
> inclusive on the lower bound and exclusive on the upper bound, and
> :FOO: with an inclusive interval.  For another example, SRFI 42 would
> break if the meaning of a colon prefix were changed in Scheme's
> lexical identifier syntax, although if any extension were to be made
> I'd prefer the colon prefix.

I'm not sure I understand your point.  I'm advocating for a colon
suffix.  SRFI 42 uses a colon prefix on identifiers (which by the way
is illegal in R5RS except for a lone colon).  So keyword objects
using a colon suffix syntax do not hinder in any way SRFI 42 or any
R5RS compliant code, but a colon prefix syntax does.

I know that some code has used colon suffixes on identifiers (for
example the withdrawn iota: function in SRFI 1), but there are very
few uses of this and it is not portable anyway so I don't think this
argument has much weight.

Marc