Re: Patch: enhanced mark navigation commands

[Ted Zlatanov <tzz@lifelogs.com>]

On Wed, 05 Mar 2008 14:20:23 -0500 Stefan Monnier <monnier@iro.umontreal.ca> wrote: 

>> Would next-error and previous-error (which are useful for any motion to
>> "points of interest" and have aliases defined accordingly) be
>> appropriate here?  They already handle occur-mode, grep-mode, and
>> compilation-mode point of interest, and the intent is to provide a DWIM
>> interface.

>> It makes sense that if any of those three modes are not on, next-error
>> and previous-error should move to recent edit points.  If one of those
>> modes is on, we can provide an override, but I expect users to be happy
>> with the default behavior as I describe it.  What do you think?

SM> And then as soon as you run grep, diff, or compile, the feature just
SM> can't be used any more?  Doesn't sound too good to me,

I think it's possible to make this useful with navigation layers.

Layers 0-9 reserved for char/word/paragraph/page/etc motion
Layer 10: edits (what Adrian Robert's patch provides)
Layer 11: tags (ctags, etags, etc.); function/variable definitions
Layer 12: grep/diff/compile/occur points
Layer 13: buffers (like cycle-buffer)
Layer 14: Gnus articles or dired files or other bundles of information
Layer 15: Gnus groups (or other aggregators for layer 14)
Layer 16: Gnus topics (or other aggregators for layer 15)

Layers 10 and 11 may have to be swapped.  We may think of more layers,
and what I've listed above is just an idea.  The point is that we'll
give the user a way to move back and forth between things that are
interesting.  Selecting the motion layer can be done in some standard
way, e.g. next-error--10 or whatever makes sense.  I also don't know if
numerical layers will work as a concept, but they seem simple to
understand and configure.

Ted