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

[Ted Zlatanov <tzz@lifelogs.com>]

On Sun, 10 Jul 2016 17:05:04 -0400 Stefan Monnier <monnier@iro.umontreal.ca> wrote: 

>> Perhaps doing it how calc manages its units would be satisfactory?  The
>> short of it being that `math-standard-units' and user-defined
>> `math-additional-units' are used to build `math-units-table'.  Though,
>> for units there isn't a need to blacklist, and it sounds like a good
>> option to have for prettify-symbols.

SM> Whether the customization specifies what to include or what to exclude,
SM> there is still the issue that specific mappings could be complex
SM> (currently it's only (STRING . CHAR), but it'll likely need to be
SM> extended at some point such that you can additionally specify some
SM> predicate to check that the mapping is valid in a given context, or even
SM> to dynamically decide which mapping to use depending on context).

SM> So the mappings themselves should probably be regarded as "code" rather
SM> than customization, and the customization interface should just let the
SM> user select which mappings to (de)activate.

How about tagging each mapping? (STRING CHAR TAG1 TAG2 ...)

Then the user could include or exclude by tag. It's free-form but I
think it would be hard to provide a good general interface to
include/exclude prettifications otherwise.

Ted