bigint.vim

let s:name = 'World'
echo "\nHello" . s:name


function! Isdigit(str)
  return match(a:str, '^[+-]\?\d\+$') != -1
endfunction

let g:bigint = {'num': [], 'sign': 1}
let g:nodeMaxDigit = 8
let g:nodeMaxNum = 100000000

function! StringToBigint(str)
  if Isdigit(a:str) != 1
    throw 'is not digit: '.a:str
  endif
  let bigint = deepcopy(g:bigint)
  let bigint.sign = (a:str[0] == "-") ? -1 : 1
  if match(a:str, '^[+-]') != -1
    let l:str = a:str[1:]
  else
    let l:str = a:str
  endif
  let l:strlen = len(l:str)
  let l:nodes = ((l:strlen-1)/g:nodeMaxDigit)+1
  let l:head_node_len = l:strlen % g:nodeMaxDigit

  if l:head_node_len != 0
    call add(bigint.num, l:str[: l:head_node_len-1])
  endif

  let l:tail_nodes = split(l:str[l:head_node_len :], '.\{' . g:nodeMaxDigit . '}\zs')
  let l:bigint.num = map(l:bigint.num + l:tail_nodes, 'str2nr(v:val)')
  return l:bigint
endfunction

function! BigintToString(bigint)
  let l:str = ''
  let l:str .= string(a:bigint.num[0])
  for node in a:bigint.num[1:]
    let l:str .= printf('%0'.g:nodeMaxDigit.'d', node)
  endfor
  if a:bigint.sign == -1
    let l:str = '-' .l:str
  endif
  return l:str
endfunction

" a > b: return 1
" a = b: return 0
" a < b: return -1
function! Bigcompare(a,b)
  if a:a.sign != a:b.sign
    return (a:a.sign == 1) ? 1 : -1
  endif

  if len(a:a.num)
endfunction

function! Bigadd(a,b)
  




endfunction

function! Bigshift(a,num)
endfunction

function! Bigsub(a,b)
endfunction

function! Bigmul(a,b)
endfunction

function! Bigdiv(a,b)
endfunction

function! Bigmod(a,b)
endfunction