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

[Ian Hulin]

Hi David,
On 29/10/11 13:22, David Kastrup wrote:
> 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.
> 
>> !!Ping!!<<  @image{Picture-of-lightbulb-lighting-up}
Got it.
>> 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).
> 
OK, I'll hack together a text file.  Do you want to do this via e-mail
or Rietveld?
> But I don't have the resources to do this better myself.
> 
OK.  It's on my to-do list.  I'll take a break from the Guile V2
Migration cave. . .
Cheers,
Ian