Re: scheme-tutorial.itely: avoid unnecessary copying (issue 5314065)

[David Kastrup]

Ian Hulin <address@hidden> writes:

> Hi David,
> I don't want to get into a flame war here, as I think you're trying to
> amend a section of manual here that needs a re-think/re-write.

No flame war intended.  As I said: I can't expend the effort to do this
well.  I got annoyed by wrong information and corrected it.

The point was that it is nonsensical to copy material with an arcane
function ly:music-deep-copy when you already got a copy handed by
Lilypond, which happens every time information passes through a
MUSIC_IDENTIFIER token (also the case for $music constructs in #{
... #}).  When you refer to a variable via \music in Lilypond, you
already get a copy.  When you refer to a variable via #music in Scheme,
you get the original.  Lilypond's own music functions have no qualms
working destructively.  There is no point in the user trying to be
different, in particular since there is a dearth of convenience
functions for that purpose.

> I can have a look at this section and think about a redraft. Carl, do
> you have enough time to review a draft for Scheme-fu if I write the
> first draft in OpenOffice Write?

I am willing to answer questions and look at drafts (though not in
Oowrite).

But I don't have the resources to do this better myself.

-- 
David Kastrup