[Larceny-users] R6RS syntax-rules

[David Rush]

I notice that R6RS adds another legal pattern to syntax-rules. Specifically,

(<pattern> ... <pattern> <ellipsis> <pattern> ...)

which is not legal in R5RS as <ellipsis> must always be in a trailing
position. Larceny v0.97 "Funny in the Head" doesn't appear to support the
R6RS syntax, as well it might not although it is staggeringly useful. Is
this intentional (and I should switch to R6RS mode), a bug, or do I need to
build from HEAD in order to pick this up?

Just curious

david

[w***@ccs.neu.edu]

Post by David Rush
I notice that R6RS adds another legal pattern to syntax-rules. Specifically,
(<pattern> ... <pattern> <ellipsis> <pattern> ...)
which is not legal in R5RS as <ellipsis> must always be in a trailing
position. Larceny v0.97 "Funny in the Head" doesn't appear to support the
R6RS syntax, as well it might not although it is staggeringly useful. Is
this intentional (and I should switch to R6RS mode), a bug, or do I need to
build from HEAD in order to pick this up?

Larceny v0.97 supports that syntax in R6RS and ERR5RS modes.
It does not support that syntax in R5RS mode.

The reason for that is that R5RS mode continues to use the
macro expander I wrote a long time ago, not Andre van Tonder's
new macro expander as used in R6RS and ERR5RS modes.

I'll create a ticket for that later today, but I'm not sure
what priority it should have. I'd like to hold off on this
kind of change until I see what kind of macro/library system
is devised by the new working group 1; that group's status
report is now up on their web page, which can be reached via
http://www.scheme-reports.org/

Will