Re: [Scheme-reports] Formal - Internal syntax definitions vs a body with definitions being a letrec*
John Cowan 28 Jun 2012 03:58 UTC
Jussi Piitulainen scripsit:
> I desire a clarification on how a body that begins with internal
> definitions can be equivalent to a letrec* when syntax definitions are
> valid wherever definitions are.
Formal Comment #414 filed.
The language in 5.2.2 now reads:
# An expanded \hyper{body} containing internal definitions
# (but not syntax definitions or record definitions) can always be
# converted into a completely equivalent {\cf letrec*} expression.
> Finally, I still have a related concern about <body>: the entry on
> lambda expressions does not tell the truth about <body> allowing
> internal definitions, yet several binding constructs refer to it as
> being authoritative about <body>:
>
> 4.1.4 Procedures (p. 12 bottom right)
> ... <body> should be a sequence of one or more expressions.
> [this does not allow internal definitions]
Technically this is a substantive change, but arguably it is an error in
R5RS. In my suite of 45 Schemes, only Oaklisp (which treats all defines
as external) and UMB (which has a bug here) do not accept ((lambda (x)
(define y 32) (+ x y)) 45) as correct and returning 77. Therefore,
I have treated this change as editorial, making it read:
# \hyper{body} should be a sequence of zero or more definitions
# followed by one or more expressions.
> Finally finally, "body" is not an index entry (p. 77) and it should
> be. Probably it should point to 4.1.4 but, as noted above, that site
> does not tell the truth about <body>, or body, and maybe to 5.2.2,
> where I'm formally seeking clarification. Thank you for your
> attention.
Editorial ticket #415 filed. This will be done before the next draft.
Since all these changes are editorial, I am closing this Formal Comment.
Please treat this as a formal response.
--
Not to perambulate John Cowan <cowan@ccil.org>
the corridors http://www.ccil.org/~cowan
during the hours of repose
in the boots of ascension. --Sign in Austrian ski-resort hotel
_______________________________________________
Scheme-reports mailing list
Scheme-reports@scheme-reports.org
http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports
