Re: org-pop-mode

[Adam Porter <adam@alphapapa.net>]

"Mark E. Shoulson" <mark@shoulson.com> writes:

> Heh; fair enough.  The filename originally was "org-level-end.el", I
> think; I started using the catchier "org-pop" because... well, it was
> catchier.  It made sense in my mind, in the "push"/"pop" sense used
> with stacks in programming, that you "push" to a deeper level and this
> library would allow you to "pop" back up to a higher one.  I'll see if
> I can think of something better, thanks.

Well, org-heading-push-pop wouldn't be a /great/ name, but the push/pop
paradigm is understandable, so you might consider that.  :)

>
>> 2.  In the code, I saw you comment about cl-flet, and I see you using
>> fset and unwind-protect in the org-pop-with-continuations macro.
>> Instead, use cl-letf with symbol-function, like:
>>
>>    (cl-letf* (((symbol-function 'foo)
>>                #'my-foo)
>>               ((symbol-function 'bar)
>>                (lambda ()
>>                  ...)))
>>      BODY)
>>
>> See also Nic Ferrier's package, noflet.
>
> I'll take a look, thanks.  It's questionable whether I really should
> even be messing about with that macro anyway.  I musnt have removed the
> comments, but I had a whole thing there about how I had been trying
> with cl-letf and/or cl-flet and it didn't work. Thing is, cl-flet,
> according to the docs, (info:cl#Function Bindings) is strictly
> *lexical* binding, which is not going to cut it.  cl-letf might be
> different; the docs are different about it, but I am pretty sure I
> tried it and it didn't work, or didn't work "enough of the time."  But
> maybe I had it wrong, and maybe noflet will succeed.

The issue is what the macros expand to.  cl-letf rebinds the function
symbols, just like fset, so it affects all code that runs in Emacs until
the function symbols are set again.  cl-flet expands into lambdas bound
to variables and replaces calls to them with funcall, so it only affects
calls in the macro's body.  Use pp-macroexpand-last-sexp to see the
expansions.

BTW, in the body of your email, the text you write has these two
characters between sentences: "  ".  The second is a plain space, but
the first is a Unicode non-breaking space, or "C-x 8 RET a0".  I noticed
because it's displayed in Emacs as an underline character next to the
plain space.