RE: Making ielm behave like a shell (getting to previous commands using the up-arrow key)

[Drew Adams]

> It's debatable how large defuns should be.  In the Emacs sources, a lot
> of them could be split or refactored indeed.  What we have is the result
> of a development.  In the repositories, small changes are preferred and
> are better traceable with version control systems, and refactoring is an
> unrewarding job that even messes git history.  As a consequence, defuns
> tend to grow.  I guess that is one side of the phenomenon called "bit
> rotting".
> 
> The other side is that what one might consider as an ideal size of
> defuns (or "factors") in his code might vary with your familiarity and
> experience with the language and the project.  Experienced people might
> find relatively large units ok that would be not acceptable for somebody
> for whom working with that language is not daily business.

All good points.  For the last bit: familiarity
with the language, yes.  But even familiarity
with the particular code can make a difference.

Understandability and changeability are affected
by function def size, and even library size
generally.  But the structure and complexity of
the code can make an even bigger difference.

E.g., a long function def that's simple, clean
and straightforward might well be easier to deal
with than a set of small functions that are not
so clean and clear but that have equivalent
behavior.  It all depends...