Formal comment #14 (defect)
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.