[R6RS] R5RS-compliant mode

[Matthew Flatt]

At Tue, 07 Sep 2004 09:42:08 -0400, William D Clinger wrote:
>   * missing features, e.g. the R5RS macro system

As of v208, `letrec' in MzScheme/MrEd/DrScheme is still broken, because
it's implemented as `letrec*'. I think that's the only bug on the input
side.

>   * case-sensitivity
>   * nonstandard escape characters (e.g. vertical bars) being printed
>     for symbols of mixed case that are created by STRING->SYMBOL
>   * nonstandard printing of vectors, e.g. #3(a b c) instead of #(a b c)
>   * nonstandard printing of lists, e.g. square brackets instead of
>     parens when printing lists that look like Scheme code

MzScheme/MrEd/DrScheme have the problem with non-standard escape and
vector lengths. They can be disabled dynamically with

 (read-accept-bar-quote #f)
 (print-vector-length #f)

I can't think of anything else that's broken (nothing else relevant is
in the list of read/print-control parameters), but I didn't think of
these before, either.

Matthew