Add support for vim digraphs

[alecjacobson]

With vim bindings in insert mode, CRTL+K currently deletes all subsequent characters on the current line. I don't believe this is the default vim behavior.

In vim locally, pressing CTRL+K then two letters will insert a unicode character based on its digraph. This is a very handy way of typing unicode characters with a standard keyboard.

If there's an existing way to use vim digraphs in ACE, what is it?

If not, I would like to request supporting vim digraphs as a new feature.

[nightwing]

Insert mode uses general editor key bindings for keys that are not overridden by vim mode. Behavior of Ctrl-K is present in all textareas on mac. Currently there is no way to use digraphs in ace.

Is there a simple rule by which digraphs are defined or would we need to include the whole list of digraphs in the editor?

[alecjacobson]

Some of the digraphs have patterns: e.g., f* → φ, s* → σ, but most are two letter abbreviations intended to be easy to remember .p → ⋅ ("dot" P-roduct).

Probably best to just take the full digraphs table. In vim, this will show up if you type :help digraphs. If you type :digraphs you sees the full screen table with just codes and symbols.