for.cpp

   1 // 'for' function
   2
   3 #include "stdafx.h"
   4 #include "defs.h"
   5
   6 #define A p3
   7 #define B p4
   8 #define I p5
   9 #define X p6
  10
  11 void
  12 eval_for(void)
  13 {
  14         int i, j, k;
  15
  16         // 1st arg (quoted)
  17
  18         X = cadr(p1);
  19         if (!issymbol(X))
  20                 stop("for: 1st arg?");
  21
  22         // 2nd arg
  23
  24         push(caddr(p1));
  25         eval();
  26         j = pop_integer();
  27         if (j == (int) 0x80000000)
  28                 stop("for: 2nd arg?");
  29
  30         // 3rd arg
  31
  32         push(cadddr(p1));
  33         eval();
  34         k = pop_integer();
  35         if (k == (int) 0x80000000)
  36                 stop("for: 3rd arg?");
  37
  38         // remaining args
  39
  40         p1 = cddddr(p1);
  41
  42         B = get_binding(X);
  43         A = get_arglist(X);
  44
  45         for (i = j; i <= k; i++) {
  46                 push_integer(i);
  47                 I = pop();
  48                 set_binding(X, I);
  49                 p2 = p1;
  50                 while (iscons(p2)) {
  51                         push(car(p2));
  52                         eval();
  53                         pop();
  54                         p2 = cdr(p2);
  55                 }
  56         }
  57
  58         set_binding_and_arglist(X, B, A);
  59
  60         // return value
  61
  62         push_symbol(NIL);
  63 }
  64