RE: linum.el -- Display line numbers to the left of buffers

[Drew Adams]

> > This is an alternative to setnu.el. It works incrementally and can
> > number large files fast. As it redraws all visible line numbers after
> > each command, it can also recover from potential layout glitches.
>
> Compiler warning:
> ,----
> | In linum:
> | linum.el:87:6:Warning: `make-local-hook' is an obsolete
> function (as of Emacs
> |     21.1); not necessary any more.
> | Wrote /dev/shm/linum.elc
> `----

Yes. The use of such obsolete functions enables libraries to work with older
versions of Emacs, as well as the latest version.

linum.el is a good library, and there is no reason to deprive Emacs 20 users
(and there are many) from using it. I hope Markus will continue to keep
linum.el version-agnostic as long as that doesn't sacrifice functionality.

Sometimes, a newer Emacs version offers features that are difficult to
reproduce in older versions. If a library depends on such a feature, then
there is no reason for it not to also use other new features. But, if other
things are equal, why not make the library available to more users, by
foregoing new features that are not really needed and exploited as such?

It's good that the byte-compiler makes us aware of obsolete functions and so
on, but that doesn't mean that we should always replace them by what is
currently recommended - it depends on the context and the need.