How to call a macro as a function in a search replace %s/regex/\=call-macro-as-function/gc

Question

I want to do some edits on each match during a global substitution operation.

I found this answer

:% s/re\(ge\)xp/\= myfunction(submatch(1))/gc. 

But I don't have a function, just some keystrokes.

So how can I wrap a macro into myfunction to call during substitute?

Sample use: rot13(vselection) is g?, but rot13 is not a function in vim:

:%s,(re)(ge)(xp),\1\=rot13(submatch(2))\3,gc

I found a workaround by using the bash utils without using macros this answer.

%s/m\(atm\)ul/\=substitute(':' . system('echo '.submatch(1).'|tr A-Za-z N-ZA-Mn-za-m'),'\n','','g')/gc

interactively changes 'matmul' to ':ngz:'

Answer 1

I would suggest the following:

Record your keystrokes as a macro (here in the register q) and call:

:g/regex/normal @q

This will apply the macro on each found regex in your document.

Example of use:

Content of your file

function A(){}
function B(){}
function C(){}

Type:

/function<CR>           " search for function
qqg?gnq                 " in a macro, rot13 the matched `function`
:%g//normal@q<CR>       " repeat for all `function` in the file

See:

• :h :g
• :h :normal
• :h g?
• :h gn

Answer 2

With :substitute (especially the replace with expression), you get the exact match (or any submatches), and you can transform / reorder / invoke functions on that easily.

Normal mode commands (like g?) can directly edit text, but they usually work on lines or text covered by {motion}.

What you're asking for is a cross between the two. Since there is not rot13() built-in function, you either have to provide that yourself (and then use :s//\=rot13(submatch(0))), or relinquish the regexp matching of :s and use :global (and / or :call search()) in combination with :normal! g?.