Re: Language Setup Document

[Alexander Malmberg]

Kazunobu Kuriyama wrote:
> Alexander Malmberg wrote:
> >> Broadly speaking, Unicode defines a one-to-one mapping from an integer
> >> to a glyph
> >> or the shape of a character,
> >
> > This is wrong. Unicode defines abstract characters. These do not map
> > one-to-one to glyphs.
> >
> This is just the place I felt difficulty to put my thoughts in sentences.
> It seems to me that the concept of 'abstract characters' is useful to
> make argument rigorous and neat.  Is this a technical term?

I just meant "characters" in an abstract sense, but I think Unicode uses
"abstract character" for a character when taken independent of its code
point.

> If so,
> could you tell me the place I can find its definition and study more?
> 
> Perhaps, the def may be like this: An abstract character is a set of all
> possible glyphs of a given character.

The "character" concept is very hard to define in a strict way, and the
concept is somewhat fuzzy (are 'A' and 'a' the same characters? 'A' and
Cyrillic capital A, Greek capital A? 'A' and an italic 'A'?). I don't
have the unicode standards, so I can't check whether they give their
definition of it.

http://www.cs.tut.fi/~jkorpela/chars.html is probably a good read, in
particular http://www.cs.tut.fi/~jkorpela/chars.html#characters , which
offers the following definitions:

""the smallest components of written language that have semantic value""

and:

""a unit of information used for the organization, control, or
representation of textual data""

- Alexander Malmberg