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Re: [Scheme-reports] 7.1.1 lexical structure
- To: Andy Wingo <wingo@x>
- Subject: Re: [Scheme-reports] 7.1.1 lexical structure
- From: John Cowan <cowan@x>
- Date: Sat, 21 May 2011 18:11:29 -0400
- Cc: scheme-reports <scheme-reports@x>
- In-reply-to: <firstname.lastname@example.org>
- References: <email@example.com>
Andy Wingo scripsit:
> WHITESPACE is specified as SPACE OR NEWLINE. Should TAB be included?
> LF? Some unicode category?
I don't think so. Schemers don't use hard tabs anyway, and the other
Unicode whitespace characters are for special purposes only. Supporting
them means the lowest-level character dispatcher has to be UTF-8 aware
on UTF-8 systems, whereas all other significant characters come from the
> What is the deal with PECULIAR IDENTIFIER? Is +.+ useful for someone?
> It seems an odd production, given that implementations are free to
> extend the set of valid identifiers. The R5RS was clearer here.
This allows identifiers like +foo+, that can't be mistaken for numbers.
> I am bothered by the SYNTACTIC KEYWORD section. Whether or not
> something is a keyword depends on scope; only sometimes does it only
> depend on name.
Yes. I'm wondering if all that syntax-dependent stuff, which dates back
to R4RS, shoudn't be removed. Editorial ticket filed.
> Do people really use the #-is-a-placeholder-digit thing? Yuk! This
> should be allowed (as any implementation extension would be) but not
I tried to get rid of that, but the WG went for backward compatibility.
> The INFINITY -> +nan.0 seems a bit sloppy, naming-wise.
If you knows of a better 'ole, go there. I tried for a bit to find a
> Also, DEFINITION -> (begin DEFINITION*); this does not allow
> (begin (begin (define a 1) a))
Editorial ticket filed.
John Cowan cowan@x http://www.ccil.org/~cowan
Most languages are dramatically underdescribed, and at least one is
dramatically overdescribed. Still other languages are simultaneously
overdescribed and underdescribed. Welsh pertains to the third category.
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