[R6RS] Re: Why there are two syntactic layers

[Anton van Straaten]

Marc Feeley wrote:
> At this point and before we can consider submitting this proposal as  a 
> SRFI, we really need all the other editors (Anton, Matthew and  Will) to 
> enter the discussion and state their position.

I was hoping some more agreement would be reached before I jumped in. 
If that's not the case, I'll respond in more detail either tomorrow, or 
over the weekend.  I'll just summarize my general perspective now, and a 
few specific points I'd like to respond to.

I consider a procedural interface important to supporting third-party 
tools, and I like the procedural interface in Mike & Kent's proposal.

In many ways, the procedural interface seems more appropriate to me for 
the core language than any of the proposed syntaxes.  That's perhaps 
largely because there seems to be less to disagree on, assuming one 
accepts the need for a procedural interface.

(It's also occurred to me that providing a procedural interface alone 
would be a step forward, in the same sort of way that previous RnRS 
reports have provided call/cc with no specific exception mechanisms.  I 
realize that that's probably not enough for R6RS, though.)

On the syntactic interfaces, I share some of Marc's concern about the 
two-layer interface, unless there's some rationale for it other than 
that of a compromise amongst the editors.  That's not a great reason to 
have to give people when explaining features of the language.  I'll save 
further comment on that until I've had a chance to think about it more 
carefully.

Regarding the keyword issue, Marc has concerns about parenthesitis, but 
I have some concerns about keyworditis.  "constructor" and "predicate" 
are both quite long, for example.  I agree with Marc that "mutable" 
should ideally be a default that doesn't need to be specified.

I'd like to spend some more time looking at both proposals, and see if I 
can make any constructive suggestions.

(Aside: in an OO language product I worked on in the early '90s, I 
provided "ctor" as an optional abbreviation for "constructor" - it's 
butt-ugly, but at least it's short.  People used it without complaint. :)

Anton