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semantics of DEFINE
Date: 30 Apr 89 20:39:25 GMT
From: Krulwich-Bruce@yale-zoo.arpa (Bruce Krulwich)
In article <19890425161147.8.DEATH@MICKEY-MOUSE.LCS.MIT.EDU>, death@ZERMATT
(Mark A. Sheldon) writes:
. . .
A while ago I posted the suggestion that non-top-level DEFINEs do
the same thing as top-level DEFINEs, ie, side effect the top level.
. . .
Most of the responses that I got said either like "well, Abelson
and Sussman used the 'local' interpretation, so we really should
stick to it" or "well, local non-top-level DEFINEs add fewer
parentheses than nesting LETRECs." Does anyone have other
(theoretical or functional) reasons for this decision??
How about a general aversion to the notion of "top-level environment"? When
you introduce first-class environments, and programming tools for using
them, the notion of "top-level" starts to change. Just how it changes
depends on how the environments and programming tools are designed.
Do you have a problem with the following, aside from the general aversion
to SET! ?
(define frob nil)
(let ((x (mumble1))
(dset! frob (lambda (z)
(list x y z))))