Hi -
On 2/17/2020 2:14 PM, Christian Hopps wrote:
...
If you are talking about the property categories (where I see 'Z'
mentioned as "All separators") then there doesn't appear to be a
"lower means include, upper means exclude" relationship. Also it
appears that to refer to one of these things the syntax is actually
"\P{Z}" or "\p{Z}" not just "Z". So translating maybe that's "[\P{Z}
]"? I see nothing that defines how "catEsc" (\p{}) vs "compEsc" (\P{})
are different, but maybe the upper here means exclude.
My error. You're right that "[\P{Z} ]" is what the grammar would require
to eliminate all the space-like things while still allowing #x20 space.
The problem with "\S" is that the only kind of space it eliminates is #x20,
(which you then add back in in the regular expression) while Unicode has
a whole menagerie of other space-like creatures one might well want to
exclude from tags while still permitting #x20, as well as lots of other
stuff
that is probably a bad idea to permit in tags. That said...
I'm more inclined to just ditch any pattern or restriction the more
this gets discussed. Let the user do what they want. If they want to
include crazy unicode stuff (almost certainly they dont) then I guess
that's what they want.
Yeah, doing so is almost a design pattern in Yang: try to constrain
things with
regular expressions, find out the expression is either too limiting or
allows too
many invalid strings, then give up. :-) No judgement here - it is what
it is, and
"done" has to take precedence over "perfect."
Randy
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