Re: "invalid datums in quotation" should be suppressed

Jonathan Rees <[email protected]> writes:

>> ((eval (list 'quote (lambda () 'hello!)) (scheme-report-environment 5)))
>
> Warning: invalid datum in quotation
>          #{Procedure 8664}
>          (&warning)
> 'hello!
>> 
>
> The spirit of the warning is correct, but there should be
> follow-through in the form of replacing the (quote ...) form with
> syntax error code, as happens with other static errors e.g.
>
>> (lambda ())
>
> Warning: invalid expression
>          (#{Name lambda} ())
>          (&syntax-error)
> 'syntax-error
>> 
>
> (Better would be for a run-time error to result, not just a bogus value.)
>
> The reasoning is the same as that for converting mutable to immutable
> values when they're quoted, and has to do with supporting
> cross-compilation and capability security applications. The
> prohibition is allowed by the Scheme reports (due to the specified
> syntax of the QUOTE special form).

For now, I'm going to to treat this the same way as `(lambda ())', which
is by calling `syntax-violation'.  This makes it a hard error rather
than a warning, with the possibility of deferring until run-time later.

-- 
Regards,
Mike