Greek beta code conversion within (n)vim

Question

I would like to be able to use Greek Beta Code in vim so that I do not need to keep changing keyboard layouts while typing a mixture of Greek text, LaTeX commands, and vim normal-mode commands.

Is there some way to do this in insert mode --- and/or a normal/visual-mode command to change existing Greek Beta Code to Greek polytonic Unicode? For an example of such conversion see this website.

Answer 1

Digraph

I would do in insert mode: Ctrl kb*

Where Ctrl k lets you insert digraphs (combination of two characters that translate into one Unicode character)

You can also introduce your own digraph with the digraph command.

:help digraph

Abbreviations

As an alternative you could introduce abbreviation with the iabbrev command:

iabbrev b* β

Then b*Space will be converted into β

Mapping

Another alternatives would be to introduce mapping:

inoremap b* β

Then b* will be converted into β

Answer 2

An alternative approach

As I noted in a comment, a solution to my use case occurred to me (though it is not strictly speaking an answer to the question as I posed it), namely to make normal mode mappings like nmap ξ j which allow me to switch to normal mode and then keep typing with the Greek keyboard layout but have it behave as if I were typing the same keystroke with the English layout.

In case it is useful for others, here are the mappings I've come up with so far (others will probably occur to me as I work):

imap ξκ jk
nmap ι i
nmap Ι I
nmap α a
nmap Α A
nmap ξ j
nmap κ k
nmap λ l
nmap η h
nmap β b
nmap Β B
nmap ς w
nmap Σ W
nmap ε e
nmap γε ge
nmap σ s
nmap Σ S
nmap φ f
nmap Φ F
nmap τ t
nmap Τ T
nmap υ y
nmap υυ yy
nmap μ m
nmap Μ M
nmap μμ mm
nmap χ x
nmap δ d
nmap δδ dd
nmap Δ D
nmap π p

Corollary question

A corollary question then would be (perhaps I should pose this as a separate question?): is there some way to automate this, i.e., to tell vim to convert all Greek Unicode inputs to Latin characters except in insert mode? The idea would be to feed vim the two keyboard layouts and have it do the converting.