[r6rs-discuss] Lexical Syntax

[William D Clinger]

Alan Watson wrote:
> If I read an R5RS symbol using the R6RS read procedure, I still get a
> symbol, although I may be surprised by its case. It is, however, easy to
> remove the possibility of surprise by using a procedure that replaces
> symbols in a datum by appropriately case-converted equivalents.
>
> If I attempt to read #\SPACE or #\NEWLINE using the R6RS read procedure,
> I get a &lexical exception.
>
> These seem quite differently dangerous to me.

Good point.  Since the &lexical exception may not be
continuable, the R6RS read and get-datum procedures
are essentially useless when reading R5RS data.

It sounds as though the R6RS has created a need for some
kind of tool and/or language that would allow us to read
R5RS data reliably and then to write that data reliably
as R6RS-readable data.  Perhaps someone could design such
things.

Will