BufferList

" BufferList object
" ARB
" version 0.5

function! BufferList()
  let bl = {}
  let bl.buffers = {}
  let bl.current = 0
  let bl.alternate = 0

  " public interface

  func bl.update() dict
    redir => bufliststr
    silent! ls
    redir END

    let bufferlist = split(bufliststr, '\n')
    " Reorder and clean up a bit the output.
    for i in range(0, len(bufferlist) - 1)
      let bufferlist[i] = substitute(bufferlist[i], '^\s*\(\d\+\)\(\s*[-u%#ah=+x ]*\)\s\+\"\(.\{-}\)\"\s\+line\s\+\(\d\+\)\s*$', '\1,\2,\4,\3','')
    endfor

    " Split on commas.
    call map(bufferlist, 'split(v:val, ",")')
    " Restore file names with comma(s)
    call map(bufferlist, 'add(v:val[0:2], join(v:val[3:-1], ","))')
    " Empty names give an empty string instead of "[No Name]".
    call map(bufferlist,
          \ '{"number": v:val[0],'
          \.'"line": v:val[2],'
          \.'"name": (v:val[3]      =~ ''\[.\{-}\]'' ? bufname(v:val[0]) : v:val[3]),'
          \.'"listed": v:val[1]     !~ "u",'
          \.'"current": v:val[1]    =~ "%",'
          \.'"alternate": v:val[1]  =~ "#",'
          \.'"active": v:val[1]     =~ "a",'
          \.'"hidden": v:val[1]     =~ "h",'
          \.'"modifiable": v:val[1] !~ "-",'
          \.'"readonly": v:val[1]   =~ "=",'
          \.'"modified": v:val[1]   =~ "+",'
          \.'"read_error": v:val[1] =~ "x"}')

    let self.buffers = bufferlist
    let current_l = filter(copy(bufferlist), 'v:val["current"] == 1')
    let alternate_l = filter(copy(bufferlist), 'v:val["alternate"] == 1')
    let self.current = len(current_l) > 0 ?current_l[0].number : 0
    let self.alternate = len(alternate_l) > 0 ? alternate_l[0].number : 0
  endfun

  func bl.to_s() dict
    let str = ''
    for bfr in self.buffers
      let str .= printf("%3d %s%s \"%s\" line %d\n",
            \ bfr['number'], self.buffer_type(bfr),
            \ self.buffer_status(bfr), bfr['name'], bfr['line'])
    endfor
    return str
  endfunc

  " Private functions - don't need 'dict' modifier

  func bl.buffer_status(b)
    return a:b['active'] == 1 ? 'a' : a:b['hidden'] == 1 ? 'h' : '!'
  endfunc

  func bl.buffer_type(b)
    return a:b['current'] == 1 ? '%' : a:b['alternate'] == 1 ? '#' : ' '
  endfunc

  func bl.SortByCurrent(b1, b2)
    return a:b1['current'] == a:b2['current'] ? 0 : a:b1['current'] < a:b2['current'] ? 1 : -1
  endfunc

  func bl.SortByAlternate(b1, b2)
    return a:b1['alternate'] == a:b2['alternate'] ? 0 : a:b1['alternate'] < a:b2['alternate'] ? 1 : -1
  endfunc

  " constructor

  call bl.update()
  return bl
endfunction

let bl = BufferList()
call bl.update()      " not necessary here, just showing it's callable
"echo bl.buffers
echo "Current buffer   : " . bl.current
echo "Alternate buffer : " . bl.alternate
echo bl.to_s()

" vim: et sw=2 ft=vim