H. Peter Anvin wrote:
We can disallow whitespace, and we *have* to disallow at least newline
due to the file format; I believe we should disallow all control
characters (0-31, 127-159.)
Actually, disallowing anything 128 and above means knowing the encoding
system. If we enforce UTF-8, we should presumably disallow at the very
least U+FFFE and U+FFFF too.
C99 contains a list of Unicode characters allowed in C identifiers. I
believe we should allow those characters (plus at a minimum -+.#:@) as
well, but I'd much rather we didn't make those kinds of decisions for
the user. If we have *specific* characters we can't tolerate we should
rule them out (like control characters), but even that occationally
leads to major frustration on the part of the user: "why can't I use '.'
in tag names in CVS"?
-hpa