Search and Replace with incremented values in Vim

Question

Lets say I wrote a simple CSS rule like this:

.star_10 {
  background: url(stars.png) no-repeat 0 0;
}

And I need 10, so I copied it 9 times.

Answer 1

I needed this solution but also with leading zero support. My use of the original question is more like Example 1 than what Example 2 (this was the original example).

I created a function called SearchIncr() (search, replace, and increment).

There are four required arguments: target_string, replacement_string, start_value, increment_value. There are also two optional arguments: leading_zeros, position

leading_zeros is a positive integer value, and position is 'before' or 'after'. See example 2.

---

Example 1

:'<,'>call SearchIncr("0 0","new",1,5,8)

If the file looks like this:

what 0 0 post
areu 0 0 post
doin 0 0 post

You will then get:

what new00000001 post
areu new00000006 post
doin new00000011 post

---

Example 2

:'<,'>call SearchIncr("0;","px;",-18,-18,0,'after')

If the file looks like this:

.star_10 {
  background: url(stars.png) no-repeat 0 0;
}
.star_10 {
  background: url(stars.png) no-repeat 0 0;
}
.star_10 {
  background: url(stars.png) no-repeat 0 0;
}

You will then get:

.star_10 {
  background: url(stars.png) no-repeat 0 -18px;
}
.star_10 {
  background: url(stars.png) no-repeat 0 -36px;
}
.star_10 {
  background: url(stars.png) no-repeat 0 -54px;
}

The vimscript is here:

" place functions here
function! SearchIncr(a1,a2,a3,a4,...) 
  " patn, repl, start, increment
  let target = a:a1
  let repl = a:a2
  let startval = a:a3
  let increment = a:a4

  " 1st optional argument handles leading zeros
  " process optional leading zero
  if a:0 >= 1
    let leadingz = a:1
  else
    " default to 0
    let leadingz = 0
  endif

  " 2nd optional argument handles if target string goes before or after
  " default is before
  if a:0 == 2
    " ideally set to 'after'
    let repl_pos = a:2 
  else
    let repl_pos = 'before'
  endif

  " inits
  let l:incr = startval - increment
  let lnum = a:firstline

  " cycle though selection
  while lnum <= a:lastline

    " the FORMATTING string
    if repl_pos == 'before'
      let l:incrstring = '\=printf(''%s%0'. leadingz . 'd'',repl,l:incr)'
    elseif repl_pos == 'after'
      let l:incrstring = '\=printf(''%0'. leadingz . 'd%s'',l:incr,repl)'
    else
      "default to no leading zero and before placement
      let l:incrstring = '\=printf(''%s%0d'',repl,l:incr)'
    endif

    " only increment counter when target matches
    if match(getline(lnum),target) > 0
      let l:incr = l:incr + increment
    endif

    " the search and replace
    call setline(lnum,substitute(getline(lnum),target,
    \ l:incrstring,'g'))

    let lnum = lnum + 1
  endwhile
endfunction

Any comments to improve on the above would be greatly appreciated!