partition.cpp

   1 /* Partition a term
   2
   3         Input stack:
   4
   5                 term (factor or product of factors)
   6
   7                 free variable
   8
   9         Output stack:
  10
  11                 constant expression
  12
  13                 variable expression
  14 */
  15
  16 #include "stdafx.h"
  17 #include "defs.h"
  18
  19 void
  20 partition(void)
  21 {
  22         save();
  23
  24         p2 = pop();
  25         p1 = pop();
  26
  27         push_integer(1);
  28
  29         p3 = pop();
  30         p4 = p3;
  31
  32         p1 = cdr(p1);
  33
  34         while (iscons(p1)) {
  35                 if (find(car(p1), p2)) {
  36                         push(p4);
  37                         push(car(p1));
  38                         multiply();
  39                         p4 = pop();
  40                 } else {
  41                         push(p3);
  42                         push(car(p1));
  43                         multiply();
  44                         p3 = pop();
  45                 }
  46                 p1 = cdr(p1);
  47         }
  48
  49         push(p3);
  50         push(p4);
  51
  52         restore();
  53 }