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Re: Translator todos
Re: Translator todos
Wed, 27 Sep 2006 22:05:20 +0200
Thunderbird 188.8.131.52 (X11/20060913)
Erik Sandberg schreef:
Here's a summary of my plans for the translator (I assume all of this will
happen after 2.10):
1) separate context-def into two parts, translator information and tree
information. Basically, the info shared by engraver-init and performer-init
should belong to the 'tree information', which tells us the relationships
between context types, while the stuff specific for layout and midi, such as
translators and grob properties, should belong to the 'translator' part.
2) remove recurse_over_translator and friends, replace with a dispatcher
system. This will probably be a slowdown, but not in terms of O.
3) softcode \consists, \remove as music functions. With the new event system,
it shouldn't be difficult to add/remove translators on the fly. Depends
slightly on (2).
4) remove Context::implementation. This member is currently only used by
translator groups, to search for parents and children. Once (2) is done, it's
sufficient to add a parent pointer to each translator group.
I don't have a perfectly clear picture of (1) yet, but I have a feeling that
(1) + (3) can reveal a new way of looking at context defs; if we're lucky it
may even be possible to encode all 'translator information' using Music (thus
getting a nice solution to the \tempo syntax problem).
I think I'd prefer to perform the above tasks in order 2-3-4-1.
This all sounds very good. Of course (3) implies that we'll be able to
run functions inside \translator definitions as well. I have the feeling
that this might be a can of syntactic worms. To address that I think
that it is better to do (1) before (3), because we can do (1) without
user-visible changes, i.e. we don't paint ourselves into backward
compatibility corners, while we gain understanding of how to do (3).
Han-Wen Nienhuys - address@hidden - http://www.xs4all.nl/~hanwen
LilyPond Software Design
-- Code for Music Notation