Re: comint read-only prompt

[JD Smith <jdsmith@as.arizona.edu>]

On Tue, 2002-08-20 at 14:17, Miles Bader wrote:
> On Tue, Aug 20, 2002 at 11:03:04AM -0700, JD Smith wrote:
> > Option 1 is probably the easiest to implement (simply add all
> > text-properties, including read-only, at the time of overlay move...
> > eliminating the vestigial overlay and snapshot-last-prompt altogether). 
> 
> You can argue whether the use of an overlay (and snapshot-last-prompt) is the
> best solution or not, but it's is _not_ `vestigial', it's quite intentional.
> 
> [note that the last prompt can change quite often; you can't simply plop down
> text properties and leave them there -- you have to be prepared to remove
> them later if what you thought was a prompt turns out not to be]
> 

Sorry, poor choice of words.  I did notice that snapshot-last-prompt, in
the CVS version, now adds text properties as opposed to "freeing" the
overlay, and that it gets called not just when a new prompt is created,
but *many* times, e.g. every time a command is sent (which occurs in the
background all the time in IDLWAVE).

So, in the present scheme, the current prompt has either
overlay-properties, or redundant overlay+text-properties.  All old
prompts have just text-properties.  In this context, I can't see how
overlays are uniquely needed, since they aren't predictably present by
themselves... but maybe it's just the time between when they are created
or first moved and when they are snapshotted that their presence is
important.  I had assumed you could just "plop down" text properties and
leave them, since that's effectively what happens as soon as snapshot is
called.  

Thanks,

JD

-- 
 J.D. Smith            <=> 
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