hlmgr.vim

function s:hlmgr(...)
  let this = {}
  let this.stack = []

  func! this.push(rect)
    let self.stack = [ a:rect ] + self.stack
  endfunc

  func! this.pop()
    let [ l:rect; self.stack ] = self.stack
    return l:rect
  endfunc

  func! this.matchRect(group, rect)
    let [l:l1, l:c1, l:l2, l:c2] = a:rect
    let l:cmd  = 'match ' . a:group . ' /'
    let l:cmd .= '\%>' . (l:l1 - 1) . 'l'
    let l:cmd .= '\%<' . (l:l2 + 1) . 'l'
    let l:cmd .= '\%>' . (l:c1 - 1) . 'c'
    let l:cmd .= '\%<' . (l:c2 + 1) . 'c'
    let l:cmd .= '/'
    execute l:cmd | redraw!
  endfunc

  func! this.hlRect(group, rect)
    call self.push(a:rect)
    call self.matchRect(a:group, a:rect)
  endfunc

  func! this.unhl(...)
    let l:count = (a:0 > 0) ? a:1 : 1
    while l:count > 0
      try
        let l:rect = self.pop()
        call self.matchRect('None', l:rect)
      catch
        break
      endtry
      let l:count -= 1
    endwhile
  endfunc

  func! this.unhlRect(rect)
    let l:i = 0
    for l:rect in self.stack
      if l:rect != a:rect
        let l:i += 1
        continue
      endif
      call remove(self.stack, l:i)
      call self.matchRect('None', l:rect)
      return
    endfor
    throw "rect " . string(rect) . " not found"
  endfunc

  return this
endfunction