Re: lexical madness

[Daniel L. Weinreb <DLW@SCRC-QUABBIN.ARPA>]

    Date: 2 Sep 85 15:27 PDT
    From: Masinter.pa@Xerox.ARPA

    Would removing this ambiguity in the language seriously affect any
    current implementation? 

Our implementation considers a LET that names the same variable twice to
be in error.  The interpreter does not check for the error, but the
compiler does and signals an error.  When I wrote that part of the
compiler in 1981, Common Lisp was still in its early stages of life, but
I thought it was apparent that such a case is an error.  I still think
that it ought to be considered an error, since to define it to be legal,
with any of the possible meanings that suggest themselves, would only
introduce a construct that would be confusing to someone reading the
program, and which has no benefits of its own.