Re: bidi properties from uniprop tables

[Kenichi Handa <handa@m17n.org>]

In article <87k4aako1r.fsf@uwakimon.sk.tsukuba.ac.jp>, "Stephen J. Turnbull" <stephen@xemacs.org> writes:

> Somebody misread the standard, I think.

It's me.  Actually, as far as I remember, the early version
of UCD was not clear about the property values of characters
not listed in UCD, and the early version of unidata-gen.el
was created at that time .  After that, I have not checked
the precise definitions of updated UCDs.

> Yes, a non-nil property list is required by the standard for all code
> points (not merely "all characters"), and it is obvious that in this
> case conforming to the standard is useful.

I've just installed fixes.  In the latest code,
get-char-code-property never return nil for these
properties:
  name, general-category, canonical-combining-class,
  bidi-class, decomposition, mirrored, old-name,
  iso-10646-comment.

But, it still returns nil for these properties ("string
property" in UCD terminology):
  decimal-digit-value, digit-value, numeric-value,
  uppercase, lowercase, titlecase, mirroring
UCD says that the default value is a character itself for
them, but to implement it, we have to fill all char-table
elements by corresponding characters (which makes the table
very big), or have to implement a special mechanism to
return a character ifself if the value is nil (which I think
is not adequate at the current timing of feature freeze).
So, I just added this kind of statement in the docstring.

   The value nil means that the actual property value of a
   character is the character itself.

---
Kenichi Handa
handa@m17n.org