[XeTeX] Whitespace in input

[Keith J. Schultz]

O.K.

You mention in a later post that you do consider a space as a printable character.
I do disagree, in the sense that, even though you actually can not see how many spaces are in a run,
that it does have a size and thereby does have a fixed visual affect.

I do agree with you, that a space character should, in good layout, be changed to a space of white to
accommodate good line breaking. So it is not truly a printable character in text layout.

Though, I do prefer inter character spacing a preferable method to achieve a more aesthetically look.

Know more to point.

Often enough there are conventions that one has to follow concerning the wrapping of words. Most
prominent Names. 

As an example I will use my name Keith J. Schultz. (Yes, this is not the best example and (Xe)Tex has ways
of getting around this) Names should not be wrap or should there not be unnecessary space between the parts.
Generally, it is O.K. to wrap/line break after the "J.", but not between Keith and "J." so I need a non breaking space between
them, also you do not want different space between "Keith", "J." and "Schultz", yet not the same space as used between other
words of the line. If the "J." bothers you use "Johan" instead. The same is true of Mrs. Smith.

So the use of a non breaking space with given size is advisable for input. Of course, what TeX et al. should output is debatable
and it wreaks havoc with TeX's line breaking algorithm.

It is often hard to get the desired results. But, the way TeX works this will always be a problem.
Yet, when I enter a non-breaking space that is what I want and more often than not a space of
fixed size across the board. 

regards
	Keith.



    
Am 15.11.2011 um 12:09 schrieb Philip and Le Khanh:

> 
> 
> Keith J. Schultz wrote:
> 
>> A non.breaking space is to me a printable character, in so far that
>> it is important and must be used to distinguish between word space, et all.
> 
> If, for you, "[a] non.breaking space is a printable character", then
> presumably that character must be taken from some font.  If you take
> a character from a font, it will have a size, and although it can be
> combined with kerning rules to adjust its position w.r.t. adjacent
> characters,  the logic for this is fairly restricted.  In particular,
> it cannot take into account the amount by which TeX is seeking to
> expand or contract spaces on the current line in order to achieve
> optimal paragraphs.  So in your model of the ideal universe, non-breaking Unicode spaces would not behave as do conventional
> TeX non-breaking spaces (which /do/ expand and contract to assist
> in TeX's line-breaking), nor would they conform to their Unicode
> definition where their decomposition is defined as :
> 
> 	<noBreak> SPACE (U+0020)
> 
> I wonder if you would like to discuss these points ?
> 
> Philip Taylor