How to evaluate Lua in substitution field instead of vim script?

Question

As simple example, take this:

:'<,'>s/\vs([A|B])\.size\(\)/\={"A":"a","B":"b"}[submatch(1)]/g

This substitution will replace sA.size() with a and sB.size() with b.

I would like to use lua syntax after \= command. So it will be something like

:'<,'>s/\vs([A|B])\.size\(\)/\={A="a",B="b"}["%1"]/g

Is it possible to do that in nvim? I could not find anything about this.

Answer 1

What you could do is:

:'<,'>s/\vs([A|B])\.size\(\)/\=luaeval('({A="a",B="b"})["'..submatch(1)..'"]')/g

The expression first build the ({A="a", B="b"})["A"] sub-expression using submatch using VimScript concatenation .. operator.

It is evaluated as a Lua expression in a second step by luaeval.