import "io"
import "heap"

let next(s) be
{ static { str = nil, pos = 0 };
  let begin = -1, c, r, i, n;

  if numbargs() > 0 /\ s <> nil then
  { str := s;
    pos := 0 }

  while true do
  { c := byte pos of str;
    if c <> ' ' then
      break;
    pos +:= 1 }

  if c = 0 then
    resultis nil;
  begin := pos;

  while true do
  { c := byte pos of str;
    if c = 0 \/ c = ' ' then
      break;
    pos +:= 1 }

  n := pos - begin + 1;
  if n <= 0 then
    resultis nil;
  r := newvec((n + 3) / 4);

  i := 0;
  for j = begin to pos - 1 do
  { byte i of r := byte j of str;
    i +:= 1 }
  byte i of r := 0;
  resultis r }
    
let start() be
{ let x = "   one two three      four  five six  ";
  init();
  out("from \"%s\" get:\n", x);
  while true do
  { let s = next(x);
    x := nil;
    if s = nil then
      break;
    out("  \"%s\"\n", s);
    freevec(s) } }