Path: utzoo!utgpu!attcan!uunet!nuchat!texbell!bigtex!milano!cs.utexas.edu!tut.cis.ohio-state.edu!bloom-beacon!mit-eddie!uw-beaver!uoregon!will
From: will@uoregon.uoregon.edu (William Clinger)
Newsgroups: comp.lang.scheme
Subject: Declaring variables more than once
Message-ID: <3084@uoregon.uoregon.edu>
Date: 3 Nov 88 19:28:34 GMT
References: <41415@linus.UUCP> <17416@shemp.CS.UCLA.EDU>
Reply-To: will@fog.UUCP (William Clinger)
Distribution: na
Organization: University of Oregon, Computer Science, Eugene OR
Lines: 16

In article <17416@shemp.CS.UCLA.EDU> pierce@cs.ucla.edu (Brad Pierce) writes:
>Also, is one allowed to declare the same identifier more than once in the same
>lambda closure in official Scheme?...((lambda (x x) x) 1 2) 

There's no prohibition in R3RS, but that's an oversight.  R4RS will say that
(lambda (x x) ...) is an error.  Implementations will still not be required
to detect the error.

>And is it officially legal to "define" something more than once at top level.

There is nothing that says you can't.  Many people think that a <program>
should not contain multiple top level definitions for the same variable,
but that an interactive programming environment must allow re-definitions
as a debugging feature.  This is my view.

Peace, William Clinger