In preparation for the upcoming 0.90 release I was reviewing the examples in examples/fo/basic. When looking at the output of hyphen.fo I noticed that in both the English hyphenation example and the German hyphenation example 4 consecutive lines ending with hyphens were generated.
It was my understanding that the Knuth algorithm was designed to exactly prevent this situation by adding a penalty to a hyphen break and by adding additional demerits for consecutive line ending with hyphens. Have I misunderstood the algorithm (the most likely scenario), or is the example a particular 'unfortunate' case, or is our implementation incomplete or incorrect? On a related matter: Knuth says in his paper that hyphenations in unjustified text are even less desirable than in justified text and suggests 10 times higher penalty (500 instead of 50) for hyphenations breaks in unjustified text. I don't think we do that. Manuel