RE: rectangle operations - narrowing?

[Drew Adams]

        What I'd like to do, to start with, is, in effect, "narrow"
        to a region that has the content of a given rectangle of text.
        The idea would be to operate on this region in some way, and
        then widen again - in effect putting the (possibly modified)
        rectangle back in context.

    Ordinary narrowing limits what redisplay includes.  But I think you
    would want this new rectangle narrowing to have no effect on redisplay.
    Right?

No, I'd be fine if it worked exactly like narrowing, I think. If I narrow
interactively, then only the region is displayed (redisplay wipes out the
envelope outside the region). But if I do `save-restriction', narrow,
fiddle, then widen, the user never notices the temporary narrowing.