Re: preprocessing an included file with system command

[Michael Ellis]

On Sat, Sep 24, 2011 at 4:28 PM, Graham Percival
<address@hidden> wrote:
> On Sat, Sep 24, 2011 at 01:30:55PM -0400, Michael Ellis wrote:
>> Note: what I'm actually trying to do with the preprocessing, as
>> opposed to the trivial example above,  is something that cannot be
>> done easily with a music function.  I know about the --evaluate
>> command line option but that's also not practical for what I'm trying
>> to do.
>
> Does the preprocessing require scheme?  If you're just using sed
> or m4 or python, I'd do this:
> # mylily.sh
> cp $1 /tmp
> sed '...' /tmp/$1 > /tmp/$1-processed.ly
> lilypond /tmp/$1-processed.ly
> mv /tmp/$1-processed.ly .
>
Thanks Graham,  I did consider wrapping the pre-processing and
LilyPond in shell script as you've described.  Here's the long
explanation of what I'm trying to do and why I've hesitated to use a
wrapper script.

I frequently use a program called Transcribe! when I want to
transcribe jazz solos or songs with no sheet music available.
Transcribe! has a very nice interface that takes a lot of the pain out
of the job.  It's really easy to lay down measure markers for the
audio and then use keyboard to short cuts to move measure by measure
through piece with the ability to loop and slow down.  You can also
type arbitrary text into entry areas associated with each measure and
have Transcribe spit the all the texts out to a single file.  So I
thought, aha! LilyPond, and now I have a template that \include's the
output from Transcribe!  Works well for purely instrumental
transcription,  less so if I have to include lyrics.  I've described
my "accumulator" music functions that let me enter lyrics and notation
on alternating lines in other posts so I won't go into that here
except to say that the invocation is a bit lengthy -- as is this
explanation, I'm afraid.

I normally do my LilyPond work with LilyPondTool and have grown quite
accustomed to its conveniences.   Using a wrapper script would mean
having to alter my LilyPondTool options to specify the wrapper script
instead of invoking LilyPond directly -- but I often  use LilyPond for
tasks other than audio transcriptions and don't want to have to keep
changing my LilyPondTool options.

I was hoping to set things up so I can enter some short hand for the
lengthier items in Transcribe!, send its output to an include file,
and use LilyPondTool to check my progress from time to time.  That
means  invoking some preprocessing on the included file to expand my
shorthand into valid ly expressions.  These include invoking
\lyricmode which doesn't seem to be practical in a music function
unless I crawl out on the bleeding edge of the most recent 2.15.x
builds.

So anyway, what I'd really like to see is a way to do simple text
substitution in  LilyPond input before parsing begins.  It's more than
a little frustrating to know that scheme with all its awesome text
munging capabilities is there but not usable for such very simple
tasks.

In the meantime, I'd settle for the ability to run shell commands on a
file and be able to include the output during parsing.   As I said in
the first post,  what I've got so far actually works.  I can live with
it as is but it would be nice not to have to remember to run it twice
each time I want to see my progress.  Failing that, it would be nice
to hear an expert explanation of why that's not possible.

Cheers,
Mike