4.3BSD - /usr/src/new/icon/functions/seq.c

   1: #include "../h/rt.h"
   2: #ifdef XPX
   3: /*
   4:  * seq(e1,e2)  - generate e1, e1+e2, e1+e2+e2, ... .
   5:  */
   6: 
   7: Xseq(nargs, arg2, arg1, arg0)
   8: int nargs;
   9: struct descrip arg2, arg1, arg0;
  10:    {
  11:    long from, by;
  12: 
  13:    /*
  14:     * Default e1 and e2 to 1.
  15:     */
  16:    defint(&arg1, &from, 1);
  17:    defint(&arg2, &by, 1);
  18: 
  19:    /*
  20:     * Produce error if e2 is 0, i.e., infinite sequence of e1's.
  21:     */
  22:    if (by == 0)
  23:       runerr(211, &arg2);
  24: 
  25:    /*
  26:     * Suspend sequence, stopping when largest or smallest integer
  27:     *  is reached.
  28:     */
  29:    while ((from <= MAXLONG && by > 0) || (from >= MINLONG && by < 0)) {
  30:       mkint(from, &arg0);
  31:       suspend();
  32:       from += by;
  33:       }
  34:    fail();
  35:    }
  36: 
  37: Procblock(seq,2)
  38: 
  39: #else XPX
  40: char junk;          /* prevent null object file */
  41: #endif XPX

Defined functions