Re: Vai word boundaries and line breaking

On 11/30/2007 4:33 PM, Michael Everson wrote:
> At 16:15 -0800 2007-11-30, Peter Constable wrote:
>>  > From: Michael Everson [mailto:[email protected]]
>>
>>>  Modern Vai always uses spaces between words. As in the Bible I have
>>>  here. Manuscript Vai is less scrupulous about this, but the Right
>>>  Thing To Do is treat the syllables like Cherokee syllables... that
>>>  is, like Latin letters.
>>
>> OK; that's helpful.
>
> I'm glad.
>
>>  > >L2/05-159R has a section on line breaking that indicates that line
>>>  >breaks are not permitted before SYLLABLE LENGTHENER or before NG.
>>>  >Looking at the beta UCD files, though, it appears that NG (A60B) has
>>>  >the same line breaking property as regular syllables (AL); it's not
>>>  >clear to me if that's intended or not.
>>>
>>>  That is Ken's bailiwick I guess.
>>
>> Well, I think Ken is dependent, like me, on the script experts out 
>> there spec'ing the desired behaviour.
>
> OK, I suck at properties, so use small words and ask me again. 
> "Intended"? Line breaks should not be permitted before SYLLABLE 
> LENGTHENER or NG. So... the properites shouldn't allow breaking before 
> them.
If something extends a word that itself consists of characters with type 
AL, then making the extender also AL has the effect of keeping the word 
together.

AL is a good default for anything that's not punctuation and that's to 
be kept with words.

Special properties are needed usually only if something can occur 
separated from a word (e.g. following a close paren, for example, or 
inside a number) and/or where it doesn't follow a 'word' made of AL, but 
things like ID (ideograph) that themselves don't bind together.

So, any marks that occur _only_ as part of words can be AL.
>
>>  > >The LENGTHENER (A60C) has linebreak = EX, as does FULL STOP (A60E);
>>>  >this strongly blocks break before. COMMA (060D) and QUESTION MARK
>>>  >(A60F) have linebreak = BA, which less-strongly blocks break before.
>>>  >(EX allows preceding break only after hard line break or ZWSP; BA
>>>  >also allows a preceding break after spaces (SP) or FFFC).
>>>
>>>  I can't say I know how to evaluate this.
>>
>> Consider this an invitation for any of the people that were involved 
>> in the Vai proposal or with any with a connection to the primary user 
>> community, to review the Unicode 5.1 beta UCD files and provide 
>> feedback as needed.
>
> I'm afraid you're stuck with me. Ask questions I can answer, and I 
> will answer them as best I can.