Re: ¬ notation for not? Ref: Add a couple cells to lisp-prettify-symbols-alist

[Ted Zlatanov <tzz@lifelogs.com>]

On Fri, 15 Jul 2016 10:50:18 -0400 Stefan Monnier <monnier@iro.umontreal.ca> wrote: 

>> I proposed tagging each prettification entry, so the user can customize
>> the tags. You said it was not right; what kind of customization are you
>> proposing? I hope we agree on it here before it gets committed.

SM> I don't know.  Maybe a kind of grouping that doesn't impose a tag for
SM> every entry?

Reversing the mapping... The tags could be sets of prettification
symbols per mode:

(defvar prettify-mode-tagsets '(emacs-lisp-mode (general . (?λ ...)) ... )
                               (ocaml-mode (math . (?¬ ...)) ... ))

(Any prettification symbols without a tagset could show up individually
in the customization dialog, allowing ad-hoc additions for the user.)

Then the user selects "general" in the options. It will be a lot of work
to maintain these sets though, I don't think it's less work than
specifying the tags for each entry. Sorry, I can't think of a good UI
that also doesn't require bookkeeping in the backend.

Oh... maybe we could look at the Unicode properties? ¬ is a math and
logic symbol for instance, while λ is a more general symbol. That might
be clever.

Ted