rewrite.cpp

   1 // Rewrite by expanding all symbols
   2
   3 #include "stdafx.h"
   4 #include "defs.h"
   5
   6 void
   7 rewrite(void)
   8 {
   9         int h;
  10         save();
  11
  12         p1 = pop();
  13
  14         if (istensor(p1)) {
  15                 rewrite_tensor();
  16                 restore();
  17                 return;
  18         }
  19
  20         if (iscons(p1)) {
  21                 h = tos;
  22                 push(car(p1)); // Do not rewrite function name
  23                 p1 = cdr(p1);
  24                 while (iscons(p1)) {
  25                         push(car(p1));
  26                         rewrite();
  27                         p1 = cdr(p1);
  28                 }
  29                 list(tos - h);
  30                 restore();
  31                 return;
  32         }
  33
  34         // If not a symbol then done
  35
  36         if (!issymbol(p1)) {
  37                 push(p1);
  38                 restore();
  39                 return;
  40         }
  41
  42         // Get the symbol's binding, try again
  43
  44         p2 = get_binding(p1);
  45         push(p2);
  46         if (p1 != p2)
  47                 rewrite();
  48
  49         restore();
  50 }
  51
  52 void
  53 rewrite_tensor(void)
  54 {
  55         int i;
  56         push(p1);
  57         copy_tensor();
  58         p1 = pop();
  59         for (i = 0; i < p1->u.tensor->nelem; i++) {
  60                 push(p1->u.tensor->elem[i]);
  61                 rewrite();
  62                 p1->u.tensor->elem[i] = pop();
  63         }
  64         push(p1);
  65 }