#include "h.h"
#include <stdlib.h>
static env work[worksize];
static int wp = worksize;
env * gw(){if(!wp) {wp=worksize; Bye("Exhausted!");} return &work[--wp];}
void crsh(char* d){printf("%s: compiler bug!", d); exit(0);}

val eval(cp x, env * e){ // Use the stack at first
  uchar op = *x;
  if (op < 253) {int j = op;
     while(j--) if (e) e = e->out; else crsh("bad sym\n"); return e->v;}
  if(op == 254) {cp argE = 3+x+*(us *)(x+1); // Where exp for argument is at.
     val f = eval(x+3, e); // function to apply
     val a = eval(argE, e); // argument to apply it to
     if(f.tag == 2) {
         if(a.tag) Bye("Numeric operator applied to function");
         return f.u.p(a.u.i);}
     {env * e2 = gw(); *e2 = (env){f.u.f.e, a};
      if (f.tag) return eval(f.u.f.c, e2);
      Bye("number as function");}}
  if(op == 255) return (val){1, {.f = {e, x+1}}};
  if(op == 253) {li y = 0; ++x;
     do y = y<<7 | (*x & 0x7f); while(*(x++) < 0x80) ;
     return (val){0, { .i = y }};}
  crsh("Invalid code\n");}