Re: LilyPond as a service

[David Kastrup]

Urs Liska <address@hidden> writes:

> I know this has been discussed in various flavors over the years, but I
> need to raise the issue once more. Please note that this actually
> encloses two questions.
>
> Would it be possible to make LilyPond work in a server mode where the
> whole Guile environment is loaded only once and the running server would
> be listening and accepting files to compile (or maybe piped .ly input or
> even Scheme music expressions)?

Shrug.  LilyPond already compiles multiple independent files/sessions
per invocation or our documentation would need even longer to build.

It's not really involved.  You just need to replace/amend the file
handling loop in lily.scm.  See how -dgui is implemented in that file.

> How fundamentally would one have to turn LilyPond's architecture
> upside down for this? Is this conceptually impossible, just difficult
> or simply too big to have been tackled so far?

Nobody cared.

> Is this a task that could *somehow* be estimated in developer
> weeks/months if one would dream of a paid developer?

A few days for the proof-of-concept implementation once you find someone
interested in sockets etc.  The actual effort, like with almost any
functionality, is not limited.  There is always one more thing you want
done.

For TeX, Jonathan Fine implemented the "TeX daemon" which does something
similar.  Nobody apart from him himself actually ended up using this
significantly (there is some web site for typesetting mathematics with
plain TeX which he programmed, or at least was).  He has a talent to rub
people the wrong way but nevertheless this kind of "shave off some more
startup time" thing apparently never was quite worth it to people.  I am
not sure whether current TeX engines are compiled for providing the
socket option still.

tex --help
[...]
-ipc                    send DVI output to a socket as well as the usual
                          output file
-ipc-start              as -ipc, and also start the server at the other end
[...]

Still there.  I don't even think that he created that option.  I think
he only used it, and it was originally needed for TeXshop or some other
GUI on the old MacOS.

-- 
David Kastrup