Re: *CATCH/*THROW -- CATCH/THROW

[Kent M. Pitman <KMP at MIT-MC>]

 From .INFO.;LISP NEWS ...

    Sunday  Sept 17,1978   FM+11H.57M.58S.   LISP 1742  -HIC, JONL-

    Changes affecting all LISPs:

    [3] *THROW, *CATCH, CATCHALL, CATCH-BARRIER, and UNWIND-PROTECT.
        For compatibility with the new format of CATCH and THROW in the
        LISP Machine, and in NIL, we are introducing *THROW and *CATCH.
        Please use these, and sometime in the future, CATCH and THROW in
        PDP10 MACLISP may be changed also.  It is recommended that old code be
        converted to *CATCH and *THROW.

 From the Lisp Machine manual, p34

    catch Macro
    throw Macro

	catch and throw are provided only for Maclisp compatibility.
	...

-----
RLB has proposed that we go through with the flushing of the old CATCH/THROW
meanings and re-defining their functionality so that they ``do what
they should have done initially, which is what *CATCH/*THROW do now.''

This would have the following effect:

  * For some period of time (as yet unspecified, probably a few months)
    CATCH/THROW would be undefined in the interpreter and the compiler 
    would continue to generate useful error diagnostics (as it has done
    for several months already).

  * After such time, the names CATCH/THROW would become synonymous with
    *CATCH/*THROW.

  * Presumably, a large amount of code currently references *CATCH and *THROW
    so we would have to allow a longer time for this last changeover, but 
    the eventual aim would be to eliminate the names *CATCH and *THROW from
    the language.

We are interested in hearing comments from the user community about how
much of an inconvenience this would be and what time spans would be necessary
to accomplish each phase of this transformation process.

To respond, send mail to CATCH-THROW@MIT-MC. Replies will end up in the file
MC:LSPMAI;CATCH REPLY if you want to see what others have to say on the issue.

-kmp