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Issue: STACK-LET (Version 1)
- To: KMP@STONY-BROOK.SCRC.Symbolics.COM
- Subject: Issue: STACK-LET (Version 1)
- From: jrose@Sun.COM (John Rose)
- Date: Mon, 27 Jun 88 13:38:40 PDT
- Cc: Common-Lisp@SAIL.Stanford.EDU
- In-reply-to: Kent M Pitman's message of Mon, 27 Jun 88 14:37 EDT <880627143734.6.KMP@RIO-DE-JANEIRO.SCRC.Symbolics.COM>
It is always permissible for STACK-LET to behave like LET.
Its use is merely advice to an implementation about the use
of a variable which might not otherwise be provable.
It would also be possible to unify this proposal with
REST-ARGUMENT-EXTENT. The technique would be to allow
(LET ((X (LIST ...)))
(DECLARE (DYNAMIC-EXTENT X))
to be rewritten by the compiler as:
(SYSTEM::STACK-LET ((X (LIST ...)))
The DYNAMIC-EXTENT declaration is a smaller, cleaner addition
than a new STACK-LET special form.
It's less of a burden on implementors and users to ignore a declaration
than to expand one special form into another.