[bp-i18n-specdev] Editorial comments on character definitions

r12a has just created a new issue for https://github.com/w3c/bp-i18n-specdev:

== Editorial comments on character definitions ==
4. Characters
https://w3c.github.io/bp-i18n-specdev/#characters

These are comments on the text recently added to the start of section 4.

[1] 1st occurrence of 'character' not highlighted same as other definitions

[2] The first para, and probably all the rest, should be under "Choosing a definition of character" subsection.

[3] there's a conflation of 'glyph', 'grapheme', and 'user-perceived character' (UPC) which i think is incorrect. A given UPC can be represented by different glyphs, eg. regular, italic, bold, alternative font, etc.  Also, a single UPC can be represented by multiple glyphs.  

[4] UPC is actually coterminous with the linguistic term 'grapheme', but graphemes are NOT 'visual units found in fonts and rendering software' - those are 'grapheme clusters' (an approximation to the concept of a grapheme expressed using rules defined by TUS).

[5] What's an 'individual rendering unit'? 

[6] We should also mention the CSS term 'typographic character unit', see https://drafts.csswg.org/css-text-3/#characters. 

[7] This is incorrect.
> It shouldn't be possible to cursor into the "middle" of a grapheme or delete only a part of user-perceived character.

It is standard to backwards delete codepoints, but to forward delete grapheme clusters.

[8] 
> When referring to 'graphemes' in this document, we mean extended grapheme clusters (unless otherwise called out).

Please don't munge those two terms. A grapheme cluster is a mechanical approximation to a grapheme.  (And note that they are defined separately in the Unicode glossary.)

Looking at the section "Choosing a definition of character", i think it could do with some reordering. I'll submit a PR for that, because i think it will make it easier to integrate the text above.

Please view or discuss this issue at https://github.com/w3c/bp-i18n-specdev/issues/28 using your GitHub account

Received on Thursday, 9 August 2018 12:44:46 UTC