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Re: [Scheme-reports] Proposed new SRFI for immutable lists

Sam Tobin-Hochstadt scripsit:

> There's also a lesson for everyone in the Scheme community, if they
> care to take it.

Some do and some don't: that's what makes horse races.

> At one time, Scheme featured `LABELS`,

In the pre-standardization period only.

> unhygenic macros,

Never standardized.

> and `(eq? 'nil #f)`.

Deprecated from the beginning of standardization (R2RS).

> Fortunately, those decisions were discarded.

Indeed, the only case of a Scheme standard which was fully backward
compatible was R5RS.

> Given the general attitude of this process toward the prior Scheme
> standard, I guess backwards compatibility is only important for bad
> past decisions.

Of the 39 changes from R5RS to R6RS enumerated in the latter
document, 22 were adopted as a whole or in part, 11 rejected
as a whole or in part, and 6 received some other treatment.
See <http://trac.sacrideo.us/wg/wiki/FiveToSixToSeven> for details.
That hardly constitutes wholesale rejection of R6RS by R7RS.

John Cowan          http://www.ccil.org/~cowan        cowan@x
XQuery Blueberry DOM
Entity parser dot-com
Abstract schemata / XPointer errata
Infoset Unicode BOM                                 --Richard Tobin

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