Re: Extracting a "score diff" from two [or more] Lilypond sources

[H. S. Teoh]

On Mon, Jan 24, 2022 at 05:02:14PM -0800, Flaming Hakama by Elaine wrote:
>    On Mon, Jan 24, 2022 at 3:40 PM Kieren MacMillan
>    <[1]kieren@kierenmacmillan.info> wrote:
[...]
>      I think it's fair to state that the vast majority of people using
>      Lilypond don't use version control.
> 
>    Sure, that may be the case.
>    On the other hand, do most lilypond users have this issue?
>    In any case, for anyone who does have this sort of a workflow task
>    to accomplish, 
>    I would suggest that it is in their interest to learn to use git.
>    You might as well also ask, do the majority of lilypond users back
>    up their files regularly?
>    I'd guess most probably don't, or not regularly enough.  
>    But if they decided to use git, they could get that for free.
>    Want to collaborate on projects?  I mean the list goes on.

Sorry for barging in here, but I second this recommendation.  One can
certainly do useful work with lilypond using a careful, manual system of
backup files (and perhaps zip files if your project is large). But
because it's manual, it's also error-prone, liable to human error, and,
in a long-term project, time-consuming and hard to manage.

Using a real version control system (not necessarily git -- though I do
recommend it -- but whatever version control software you fancy)
alleviates most of the tedium of managing backups yourself, does so
reliably, stores copies of *all* versions of your project should you at
some point suddenly need to revisit an old version from several months
ago (that you may have discarded the backup of, in the manual system).
It makes it convenient for collaborative projects, remote off-site
backups are within a few keypresses, etc..

Better yet, in my own lilypond projects I've used git branches to make
experimental changes -- while composing, perhaps an idea strikes that
requires intrusive changes; no problem, start a new branch, sketch it
out, if it turned out to be a bad idea after all, just discard the
branch and go back to where I left off and keep going with the original
version. No fiddly manual backup system and confusing yourself over
exactly which backup was the last "good" one. If it turned out to be a
good idea, merge it back to the main branch and keep going.  Sometimes
multiple ideas strike; I try each of them in turn, each in their own
branch, then pick the best of the crop.

What is *not* to recommend?  I can see only advantages to using version
control software.  Yes it requires effort to learn, but it totally pays
off in the long run.  More than compensates for the initial learning
curve for the convenience, reliability, and power it gives you.  It
takes a huge load off your shoulders for managing an intricate, fragile
system of manual backups, and puts new power at your fingertips.  This
is true not just for lilypond projects; in fact I recommend version
control for *any* project that involves extensive editing of some
product over an extended period of time.

And you get diffing between any two versions of your project for free.
The one thing I can see here that could sweeten the deal even further,
is a tool that takes a version control diff and generates a lilypond
score with the changes highlighted somehow. Say in red and bold font,
for example, or as ossia staves. Now *that* I can see as a valuable
undertaking, if it can be pulled off.


T

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