osyo-manga

function! s:fix_number(pattern, ...)
  if a:0 > 2
    return
  endif

  let s:start = get(a:, 1, get(g:, 'fix_number_default_start', 0))
  let s:step  = get(a:, 2, get(g:, 'fix_number_default_step', 1))

  let pattern = empty(a:pattern) ? get(g, 'fix_number_default_pattern', '\(\d\+\)') : a:pattern