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

[Emanuel Berg]

Barry Margolin wrote:

> Long functions are often long because of
> complex logic, which can be hard to extract
> into separate functions.
>
> Also, we tend to extract code into separate
> functions only when there's some logic to it
> -- it has to have a meaningful identity
> outside the function where it exists.
> If a function can only be used in one place,
> and refers to lots of the variables in that
> caller, then it's often hard to justify
> splitting it out -- it actually makes things
> more confusing because the modularity doesn't
> make sense.

Complexity isn't reduced by having tons of
stuff in a single function that goes on
forever- on the contrary, this makes it more
difficult to read, understand, and maintain.

But of course the modularity should make sense!

> I doubt that anyone makes decision about
> whether to split large functions into
> separate functions based on the overhead of
> function calling.

This is what the Gnus people told me when
I suggested not writing functions that are
longer and deeper than a novel by Dostoevsky -
they said, ~"Gnus is slow, Elisp is slow,
making neat modules of those defuns will make
it even slower."

-- 
underground experts united
http://user.it.uu.se/~embe8573