Re: What does everyone want? (2)

[David Kastrup]

Jacques Menu Muzhic <address@hidden> writes:

> Hello David,
>
>> LilyPond 3 could be a rework of the optimization engine doing away with
>> the hard pure/unpure distinction.
>
> Not sure I understand this, can you tell us more?

It's not a user-level distinction.  LilyPond currently makes line breaks
first, page breaks afterwards.  Page break decisions do not influence
the line break decisions.  Grobs/callbacks basically have to declare
whether they are dependent on line break decisions or not and use
different mechanisms and callbacks if they are.  That's awkward because
there often are very rare circumstances where this makes a difference in
results.

It's the main source of unexpected interactions when refining
typesetting stuff and consequently a major roadblock for
extending/fixing LilyPond: quite often a change has consequences where
other stuff is falling apart unexpectedly.  That makes a lot of the
typesetting a mine field mostly navigatable by "backend experts" since
they have experience patching up the things falling apart as they go.

-- 
David Kastrup