Formal comment #14 (defect)

<hex scalar value> should allow only 6 digits
Reported by:	John Cowan

Component:	lexicalsyntax
Version:	5.91

The maximum Unicode scalar value is 10FFFF, so 6 digits suffice.

RESPONSE:

The current limit of 8 digits is an arbitrary hold-over from a
previous attempt to be compatible with other syntaxes.

Limiting to 6 digits would be a clear improvement. Removing the limit
entirely also seems sensible, given that the range of the specific
number must be checked anyway (to be less than #x110000 and not in the
surrogate range).

A possible advantage of keeping a limit is that it might simplify the
implementation of some parsers. A certain advantage of removing the
limit is that it's simpler to specify.

In the interest of specification simplicity, the next draft of R6RS
will remove the limit.