Re: region-active-p

[Miles Bader]

Richard Stallman <address@hidden> writes:
>     > That name seems ok to me.  But I think that `region-overrides-p'
>     > hits it more accurately.
>
>     Overrides what?
>
> Overrides the command's usual behavior.

Perhaps that's how it's usually used, but to name the predicate based on
that seems sort of weird.

If I see code like:

   (if (region-active-p)
       ...do-this...
       ...do-that...)

It seems fairly clear to me what's going on (I'm assuming that people
can intuitively grasp the idea of an active region -- given the
commonness of this concept, and the suggestivenss of the term, I think
they can).

But this:

   (if (region-overrides-p)
       ...do-this...
       ...do-that...)

(1) Obscures the fact that the _reason_ for overriding the is that the
    region is active.  It sounds "arbitrary".

    In fact, upon first seeing it, it sounds like maybe there might be a
    "region-override" flag somewhere which controls the behavior, or
    that the rules were too complex to find a good intuitive name, and
    one must examine `region-override-p' to see what the actual rules
    are (I don't think this is true -- I think the _concept_ is pretty
    concise).  This makes the code harder to understand.

(2) It requires the concept of "usual" behavior to be understood,
    whereas a name phrased in terms.  Perhaps in many cases that's OK,
    but it seems like an unnecessary bit of extra information one is
    required to know.

    One can imagine a command where the "usual" case the active-region
    case, but which also has a useful non-active behavior.  For a
    command like this, the name "overrides" is awkward.

Anyway, what I'm trying to say is that a name like `region-override-p'
makes code harder to understand.

-Miles

-- 
"Whatever you do will be insignificant, but it is very important that
 you do it."  Mahatma Gandhi