Re: shouldn't `delete-blank-lines' treat form-feed as whitespace?

[David De La Harpe Golden]

Drew Adams wrote:
> `delete-blank-lines' treats SPC, TAB, and newline as whitespace.
> Shouldn't it also treat form-feed (aka \f, aka ^L) as whitespace?


While it's logically formally a whitespace class character, I'm quite 
unconvinced it would "feel right" to me.   formfeed is usually put in 
much more rarely and with more forethought than space/tab/newline.

It's also not "blank" in one possibly important sense: in emacs 
"out-of-box" it shows up as a quite visible "^L", whereas 
SPC/TAB/newline are invisible unless you turn on whitespace.

So delete-blank-lines would end up deleting lines, that from a naive 
viewpoint, look like they "have something on them".

Imagine you've got a text file with "page breaks" in it (represented as 
formfeeds as is/was the convention (see "C-x [" / "C-x ]" !)):

^L
alpha
bravo
charlie[]



                


^L
delta
epsilon


Say I hit C-x C-o where the point [] is. I wouldn't just delete those 
stray blank lines on the first page, I'd suddenly merge two pages.
So I strongly suspect changing it would annoy people who still sprinkle 
^L through their code or other files for pagination.  Something I guess
I personally don't do so much anymore (got a laser printer not a dot 
matrix...), but anyway.