[Dev-luatex] LuaTex pagination

[Hans Hagen]

On 8/4/2018 7:44 PM, Thomas de Vivo wrote:
> dear dev-luatex list,
>       I'm an estimator of (La)Tex and the
> work done Donald Knuth -- as well as the work that
> you all are doing -- and I'm following this list
> since a while.
> Few time ago I have been in touch with
> Patrick Gundlach of https://www.speedata.de/en/
> a publishing system based on LuateX.
> My concern and goal would be to be able
> to control the looseness of paragraphs while
> paging a text, so to minimize widows and orphans
> in the resulting document.
> In practical terms, when the system finds that
> a widow is being produced, then it tries to make
> the relevant paragraph more dense, or even
> more than one, in order to fit all the text
> in the page. (This is not currently possible using Speedata)
> I would like to know whether LuaTex offers such
> control, on in other terms whether the pagination
> algorithm is as sophisticated as the famous
> linebreak algorithm of Tex/Latex. (thing in
> my opinion highly desirable)
> Alternatively, I would like to know what files
> I have to check in the distribution of Lua
> to reach such a result.
You can write callbacks functions that do such things; after all you 
have access to the internals. It could work out ok for trivial documents 
but the times i played with it myself but in the end the interaction 
between different mechanisme, conflicting demands etc make a fully 
unattended automatic mechanmism that meets all demands kind of hard. 
(IRR, Don Knuth somewhere suggests to adapt the text in hard to cover 
cases.).

This is why we're not adding more heuristics to the core but expect 
users to use callbacks and mess around with lua.

Hans


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