On 06/07/2015 23:52, Karl Berry wrote:
> we would like input on how a transition to new support code
> can be managed.
> Forgive the naive question, but is it viable to make the ltluatex code
> not actually break loading the existing packages? I mean, if a document
> using the existing packages can go right on using them in the presence
> of ltluatex, then all seems well to me. If that's not possible, it
> seems to me that every existing lualatex document will require changing.
> Which seems obviously undesirable, if, I suppose, just barely possible
> at this point.
Yes anything's possible (and we gave the maintainers of
luatex/luatexbase an advance copy of this and we've bounced some ideas
around) but it's not cast in stone yet.
For a start the majority of documents don't load
luatexbase.sty/luatex.sty directly, they load fontspec to get the fonts
and thus load luatexbase via that. Fontspec obviously needs to work.
So it will not be the case that "every existing lualatex" document will
need changing, far from it.
For documents that are explicitly loading luatexbase then there would be
decisions to be made as to whether luatexbase should detect a new format
and quit or whether it should over-ride the new code and do what it
always did, or whether it should emulate any extra features that it
used to provide, but implemented now over the new format code.
However whichever one of those is chosen (and primarily that's a choice
for the existing package maintainers) I would expect the overwhelming
majority of documents to work unchanged. (package updates may be
necessary or desirable) One reason for making the draft public in this
raw state is to allow more people to experiment with real documents and
check all features are covered.
tex being tex there will probably be some edge cases where document
change is required, but with luatex that happens anyway as the
underlying engine and lua language are not cast in stone the way tex3 is.
The Numerical Algorithms Group Ltd is a company registered in England and Wales with company number 1249803. The registered office is:
Wilkinson House, Jordan Hill Road, Oxford OX2 8DR, United Kingdom.
This e-mail has been scanned for all viruses by Microsoft Office 365.