Re: SPACE...

Special spaces are, among other things, a rather old-fashioned typographic 
technique for inserting a "known" amount of space in a location.  The 
advantage of em-space and en-space (and thin and the like) is that, if 
your composition device allows it, these can be both clearly specified 
and font variable.  (I.E., My em-space in 36 point Bodini bold not just a 
generic 12-pt em.)

ASCII (currently) makes a distinction between "whitespace" (spaces and 
tabs) and special characters that happen to resolve to a space on display. 
Some of these are measured amounts of space (en, em, thin, digit, .. ).  
Some of these are behaviors, such as "hard-space" or "non breaking space".
There hasn't been a problem because SGML tools do not treat   as 
a space, and wouldn't even CONSIDER compressing "    " 
into " " although "    " is compressed to " ".  

General thoughts:

1)  At least as used in the past, an author intends for special spaces never 
to go away or be replaced by a "space".

2)  How relevant is any of this to screen display?  How 
relevant is any of this to Unicode now?

3)  If all spaces translate to "space", then who cares?  If the special 
spaces are individual characters (a la Unicode) then they are not 
"spaces" at all.  Are there any "spaces" that are not characters?

(I'm floundering here; these spaces have tied my tongue, but I know what I 
mean.  Can anyone rescue here?)

--Debbie Lapeyre

Deborah A. Lapeyre                   Phone: 301-231-6933
Mulberry Technologies, Inc.          Fax:   301-231-6935
6010 Executive Blvd.  Suite 608      E-mail: dlapeyre@mulberrytech.com
Rockville, MD USA 20852