Re: [xsl] Hyphenation in XSL FO

["Sebastian Rahtz" <sebastian dot rahtz at computing-services dot oxford dot ac dot uk>]

Gustaf Liljegren writes:
 > intention is (please correct) that implementors has to learn and make
 > hyphenation rules for different countries, languages and scripts. First of
 > all, it must be quite a large job only to implement half a dozen of the
 > most common cases within ISO 8859-1.

its been done already, for many languages

 > The only way to get things right is a hyphenation dictionary, like in
 > DSSSL, FOSI or TeX. This is what I'm thinking about:
 > 
 >   <fo:block hyphenation-exception="uri(list.txt)">

DSSSL is not a formatter, so how can it have a hyphenation exception
dictionary. Cant speak for FOSI, but TeX's hyphenation exception lists
are bundled with the patterns, and compiled in, not read at runtime.

 > appropriate places. When a word needs hyphenation the formatter check this
 > file to see in which places the word may be hyphenated. 
quite. the formatter, not XSL FO....

 > list are never hyphenated. If this feature is not added, I'm afraid we'll
 > have to wade through a lot of FO code to correct bad hyphenation before
 > processing the final output.

you dont know what the hyphenation is going to be, when you read a FO file..

 > For URIs, a special problem arise. A URI is often resulting in large spaces
 > on the following line. The best way I've seen to avoid that is to break the
 > URI after a "/", but without hyphen. Any ideas for how this exception could
 > be solved?

thats a nasty one. we solved it years ago in TeX, by putting TeX
temporarily into a math mode. I cant see how to do it in FO

 > Ideally, there would be no need for hyphenation at all. The most convenient
 > way to avoid it is to work with the space between words. Most layout
 > programs today do this one row at a time, instead of working with the whole
 > paragraph, and this seem to be the intent in XSL aswell. Why not a
 > hyphenation that check and adjust the whole paragraph?
as Knuth showed us 15 years ago already....

 > Finally, I think there should be a property for setting the minimum number
 > of characters for hyphenated words.

isnt that hyphenation-push-character-count and
hyphenation-remain-character-count?

sebastian


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