RE: Pretest begins end-June

[Drew Adams]

> > Being able to determine/regulate the behavior with a dynamic 
> > binding is an important feature.  This change would apparently
> > remove/limit that possibility.
> 
> Unfortunately not.  But it's an attempt to discourage that possibility
> by providing a suitable alternative - passing an explicit argument.

You said that binding the var would no longer work.
That is a removal/limit of that possibility.

And you do not provide a suitable alternative.  You are missing/ignoring the
general case, where the code that does the display is not necessarily available
to modify textually.

Your "suitable alternative" is workable only in the minority of cases where the
call to `pop-to-buffer' is directly available and can be edited.  You propose
source-code editing as a replacement for the programmatic control of dynamic
binding.

> IMHO an application may request (or better "suggest") 
> specific behavior and set private variables.  

Your example substitute code does not "request" or "suggest" how to display,
IIUC.  It imposes how to display, the same as the code it would replace.

Or if not, then it is not at all a suitable alternative and we are not even
talking apples and oranges but rather apples and orangutans.

> But it should not change or rebind any user option.

Obviously I disagree.  You're apparently OK with an application deciding whether
to pop up a frame, but not OK with doing that by binding a dynamic variable,
because in this case the var is a user option.

That's hypocritical and silly.  If an application controls the display, then it
has taken control for that away from the user, regardless of how it does so.

Bypassing `pop-up-frames' to do that is no more respectful of the user's general
preference as expressed by that var than is binding the var.  What is important
are the resulting behavior and the user's preferences.

Sometimes an application can be right to decide how something is displayed, in
spite of a user's general preference.  Developers need to DTRT, thinking about
the user and her preferences to decide what TRT is in any given context.
Respecting users does not necessarily mean blindly applying their general
preferences in all contexts.

If your code violates a user's general preference as defined by her
`pop-up-frames' value, it is irrelevant how that violation was implemented.

And this is more general than a question about user options.  It is about
dynamic variables in general.  Removing the ability to bind a dynamic var in
order to control behavior in code that is not directly modifiable is limiting
and, frankly, unlispy.  (No flames about lexical-only Lisps, please.)