Re: `make' written in elisp

[Ralf Angeli]

* Richard Stallman (2005-01-03) writes:

>     At least it should be able to call things like `configure' which is a
>     mandatory step in the build process of packages like AUCTeX and
>     preview-latex.  During this step the values of some important
>     variables are determined and written to the package's site
>     configuration file.
>
> Why is it important for Emacs Lisp packages to do that sort of thing?

Automatically determining variables specific to the site the package
is being installed at configuration time is a means to cut down load
times.  There are things where it is not efficient or feasible to
carry out the respective tests each time the package is loaded.

As an example, in AUCTeX we are currently using `configure' to
determine locations where TeX trees are located.  The resulting value
is used at runtime for speeding up file searches.

Another example (which is not yet implemented) is the determination of
programs for viewing DVI or PDF files on different platforms.
`configure' can check which alternative is present on the system at
hand and insert the choice into the site configuration file.  This
would allow us to get rid of the different platform-specific files we
now have.

Besides writing values to init files the configuration process is used
to check if external tools required for building or running the
package are present and provide necessary features.  A special case
might be preview-latex which has a TeX part besides the Elisp part.
For the respective file the target directory for its installation is
determined by `configure'.

-- 
Ralf