Re: Knowing where a function has been used (bis) [Was: Re: Optimising Elisp code]

[Emanuel Berg]

Garreau, Alexandre wrote:

>>> On the long term this tends lead to
>>> horrible code, where the defuns reflect all
>>> the history of the situations, as they
>>> arrived, not the problem's structure as it
>>> is *now*.
>>
>> Why is this horrible code? Isn't it just
>> natural that the code reflects how problems
>> have been solved over time, with changes in
>> technology, etc.?
>
> No, VCSes a here for that.

It is a fact of life that code develops and
grows in different directions. Different parts
of the code reflect more so the original idea,
other parts of the code refect more so
situations that arrived without anyone thinking
of them day one. This is completely natural and
not something so you can use the code as
a history book, if anyone now got that idea.

>> Isn't it much better to have this
>> "reflection" in neat modules than in single
>> functions spanning 3 A4 each?
>
> If these modules have no meaning, no, because
> it will harden the work of understanding,
> thus, for instance, of debugging, the
> function. While the same functions may have
> piece that will cancel or make useless pieces
> of other functions, if you just “add up
> historically”, you may, if you want to solve
> the problem as it is *now*, simplify the
> whole thing. And it won’t simply be
> refactoring by adding functions or macros, it
> will be removing stuff.

The modules should have have meaning and
reflect how the problem is solved now. If they,
at some point, become totally obsolete, they
are much easier to drop as modules than to try
to extract that exact portion of the original,
3 A4 long defun, without creating bugs while
doing that.

>> [1] Better yet, delete *the call* to them
>> and to move the modules to an out-of-action
>> source file, as history might repeat itself.
>
> VCS, search tools, or otherwise devs
> memories, are here for that. And even if it
> stayed in the source code anyway people are
> interested in functions that are documented
> and that they use, directly or indirectly.
> They might as well not see it if it’s
> not used.

OK, if you have found a spot where they are the
most visible, go ahead and use it. To me, an
"obsolete-source" directory is fine.

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