[metapost] independent variables overflow

[Werner LEMBERG]

Can someone please explain to me why the following snippet overflows
(with both MetaPost and MetaFont)?  What can I do to fix this?


  path line;

  for i := 0 step 0.0001 until 1000:
    line := (1, 0)
            -- (1, 1);
  endfor;

  bye;


This is METAFONT, Version 2.71828 (Web2C 7.5.6)
(zzz.mp
! METAFONT capacity exceeded, sorry [independent variables=33554431].
<for(895.98483)> line:=(1,
                          0)--(1,1); ENDFOR
l.6 endfor
          ;


    Werner