Question

Using a text editor, without writing JavaScript functions (e.g. can’t use this great answer: Replacing the nth instance of a regex match in Javascript)

How do I take something like this (a proprietary code structure I have no control over)

map(key1, value1, key2, value2, key3, value3, key4, value4 ...)

And convert it to this

map(
  key1, value1,
  key2, value2,
  key3, value3,
  key4, value4 
  ...
)

One option I found was using this regex to find every 2nd comma (([^,]*,){2})

Then replace with \1\n\t

But I would like to improve it:

1. It doen’t handle the first and last lines very well

 map(key1, value1,
    key2, value2,
    key3, value3,
    key4, value4 ...)

2. Only works on a flat structure

e.g. I can’t think of a way to transform this

map(key1, value1, key2, map(key3, value3, key4, value4 ...), key5, value5)

To this

map(
  key1,value1,
  key2,map(
    key3,value3,
    key4,value4 
  ),
  key5,value5    
)

Using regex, or is there a way?

Answer 1

Eran, oh you finally tag the question with vim, nice! ^_^

vim can format it a bit, I wrote a small function:

Note that I used \r as linebreak, if it doesn’t work for you, change into \n

function! ExpandMap()
    let s = line('.')
    exec 'silent s/(/(\r/g'
    let e = line('.')
    exec 'silent '.s.','.e.'s/),\=/\r&\r/g'
    let e = line('.')
    exec 'silent '.s.','.e.'s/,[^,]*\zs,\ze/,\r/g'
    let e = line('.')
    exec s.','.e.' normal =='
endfunction

You can put it in your .vimrc file, if you use that very often. Also you could just give it a try by typing :so %

You can create a map for that function call by:

`nnoremap <leader>r :call ExpandMap()<cr>`

in this way, if you want to reformat your map line, just move cursor to that line, and in Normal mode type <leader>r (default is \)

This function will change

map(k1, v1, k2,  map(k3, v3, k4, v4), k5, v5, k6, map(k7, v7,k8,v8,k9,v9),k10,v10,k11,v11)

into

map(
        k1, v1,
        k2,  map(
            k3, v3,
            k4, v4
            ),
        k5, v5,
        k6, map(
            k7, v7,
            k8,v8,
            k9,v9
            ),
        k10,v10,
        k11,v11
)

Here I show how it works:

• I split the window into two, just show the function
• I created a mapping after the function
• I make two nested maps, also to make the line short, I just used k#, v#

Now, when are you gonna uninstall your notepad++? ^_^