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Re: [Chicken-hackers] [Scheme-reports] R7RS-small draft ratified by Stee

From: John Boyle
Subject: Re: [Chicken-hackers] [Scheme-reports] R7RS-small draft ratified by Steering Committee
Date: Fri, 11 Jul 2014 12:03:49 -0700

I'm guessing you're looking at section "2.1. Identifiers", specifically this quote:

"An identifier is any sequence of letters, digits, and “extended identifier characters” provided that it does not have a prefix which is a valid number."

Since "1+" has the prefix "1", which is a valid number, I would agree that R7RS does not require implementations to parse "1+" as an identifier, and if you wrote a program using an un-escaped 1+, you could not be sure it would run on all implementations.  However, I think it is *permitted* for implementations to recognize additional tokens as identifiers.  R7RS does not say that 1+ is a number, or anything else, and I don't think it requires the reader to raise an exception, so if Guile accepts it as an identifier, that doesn't seem to disqualify Guile as a conforming implementation.

--John Boyle
Science is what we understand well enough to explain to a computer. Art is everything else we do. --Knuth

On Fri, Jul 11, 2014 at 10:58 AM, ceving <address@hidden> wrote:

Am Freitag, 8. November 2013 18:57:32 UTC+1 schrieb John Cowan:
The final draft of R7RS-small has been ratified by a unanimous vote of
the Scheme Language Steering Committee.


The new standard seems to ban Guile's 1+ operator. It must be quoted in R7RS |1+|.

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