Re: Window configurations

[martin rudalics]

>> I'm not sure whether I get your point.  But windows are first class
>> citizens in the Elisp world and `split-window' must be allowed to create
>> arbitrarily complex window trees on an arbitrarily complex machine.
>
> Which does not mean that any feature can be allowed to use split-window
> as it happens to think.

Features shouldn't do so, indeed.  `display-buffer' is the preferred
interface.

>> In my book a "window configuration" is "the state of all windows".
>
> In my book configuration is rules and state is result from their
> application
> (together with other conditions).  Conflating the both will just produce a
> classical chicken & egg problem.

If you specify a configuration procedurally you have to supply (1) an
initial state and (2) a set of actions and the order in which these
actions are applied.  In the context of window configurations, the state
resulting after applying (2) to (1) is the "state of all windows" as I
call it.  Hence the difference is basically only a matter of taste,
theroretically.

From a practical point of view things are different: If you want to
derive (1) and (2) from the state of Emacs at some arbitrary point of
time you do have to guess a _minimum_ set of actions/rules that
reproduce the state of windows.  Otherwise, you end up like the
designers of ECB who record _all_ actions applied by the user and
"replay" them to produce the desired state.

> There is no need to guess intentions if users were allowed to express them
> (and emacs was disallowed to ignore them).

If we can come up with some simple set of customizable variables to
express the users' intentions.  But I'm afraid we won't be able to do
that.  Suppose I want to automatically show "another" buffer in some
window.  How is this other buffer chosen?  From the list of buffers that
(a) have been already displayed in that window, (b) that window's frame,
(c) somewhere (d) are alive?

>> The heuristics should guess the "intuitively right window" in a way
>> which can be roughly measured by the number of postings criticizing its
>> implementation.
>
> You want "display-buffer" query the emacs bug tracker? ;)

More or less so, with some manual intervention ;-)

martin