On Wed, Oct 02, 2019 at 02:45:57PM +0300, Linas Stonys wrote: > Hi luatex team, > mlist_to_hlist callback requires to return a hlist. And that is a big problem > because > there is no possibility to use this callback if some style already used it. > If two different styles uses this callback luatex always throws error "! This > can't happen (mlist1)." > because mlist is already converted to hlist for second callback. > I want to offer a new callback "mlist_to_mlist" were one could access math > list without conversion to hlist. > Usually if one uses this callback he needs mlist and not a hlist. > And probably would be even better to have one more callback "mhpack_filter" > which could access result of > node.milst_to_hlist(math list converted hlist). > > So mlist_to_hlist callback would be splited into to parts like: > > m = list_of_mlist_to_mlist_callbacks (h) > n = node.mlis_to_hlist(m) > x = list_of_mhpack_filter_callbacks (n) > return x > > What do you think?
Hello, this doesn't need a change in LuaTeX, it can be implemented on top of the current callback. Basically you just have to add your code as mlist_to_hlist callback, where list_of_mlist_to_mlist_callbacks and list_of_mhpack_filter_callbacks are implemented in Lua. Additionally, you probably also want to use a callback for node.mlist_to_hlist if someone wants to customize the complete conversion. The "big problem" is a LaTeX bug: Normally mlist_to_hlist in it's current form should be an exclusive fallback, but currently LaTeX allows multiple callbacks to be registered for it, leading to the error you found. That problem exists for multiple callbacks, so you might want to report it on the LaTeX bug tracker (https://github.com/latex3/latex2e/issues). -- Marcel _______________________________________________ dev-luatex mailing list dev-luatex@ntg.nl https://mailman.ntg.nl/mailman/listinfo/dev-luatex
