Re: T2026: Use new (scm markup-facility-defs) scheme module for markup commands. (issue 5464045)

[ianhulin44]

On 2011/12/27 12:05:38, dak wrote:
> One problem that I keep having is that I fail to see any documentation
of how
> this is supposedly interacting with the module system.

> What module are user-defined markup functions placed in?  Previously,
this would
> have been a module local to the compilation unit.
They still are since patch-set 2.
> It looks like there are multiple lookups going on, yet the local
module is supposedly starting out as a
> copy of the lily module.

Markup validation looks for the declaration in the current module, in
case the new markups are nice and self-contained in the document, and
then falls back to looking up in the '(lily) module. That way we are
guaranteed access to all the definitions in (lily) defined in
scm/define-markup-commands.scm whatever shenanigans have been going on
in the user document, or lily documents the user is pulling in via
\include.

Base code markup commands - defined in scm/define-markup-commands.scm -
are in the (lily) module.  User-defined markup commands are in the local
lily scope module (anonymous module created when the new source file is
processed in lilypond-file in lily.scm).

> So where would be the documentation about what happens with macros
when and
> where?  What is the difference between code within Lilypond, and code
in user
> documents?

We maintain the stuff declared in the base code declared in
define-markup-commands.scm.  Stuff in user documents we can advise users
on how to do it right. If lots of users develop a markup that's safe,
useful, and someone asks for that enhancement, we put it in the base
code.
> Without that information, neither developers nor users can be expected
to
> continue working with confidence.  It is also not clear to me whether
macro
> definitions will bleed between multiple compilation units on the
command line.
No they won't.  This issue was addressed by patch-set 2.  It now works
as it did and is documented as well/badly as it was.  What information
do you feel is needed and how do you suggest it is supplied?

Ian


http://codereview.appspot.com/5464045/