Hans Hagen
David Kastrup wrote:
Anyway, is something like that an area that LuaTeX would actually ever consider touching? After all, it would break document compatibility. Which might be, I believe, less of a holy grail for ConTeXt than for LaTeX.
in extended mode, when using dimexpr one also gets more precission so a switch to etex mode may break backward compatibility anyway
Uh, how can there be backward compatibility broken when dimexpr did not exist previously? Do you mean compatibility to eTeX? Nobody claimed that dimexpr arithmetic is the same as TeX arithmetic (in fact, it is a **** nuisance that its integer division rounds instead of truncating).
concerning context ... truncating vs rounding is less an issue than precission (roundtrip calculations resulting in 1+ sp off comparisons) but that is/will be covered with special test stuff
TeX's way of always truncating dimensioned expressions is certainly bad for roundtripping. That "1in" is not resolved to the same value as "72.27pt" is what I'd call a roundtrip problem.
concerning latex and old docs ... there will always be pdftex vs < 2, so with luatex we have no intention to be 100% downward compatible at all (some internals may also be adapted / extended / opened up, some good old tex code may disappear (lig rebuilding already has), etc
Interesting. What do you do instead of ligature rebuilding? -- David Kastrup