Free Hero Mesh

      if(v1) Push(UVALUE(v1-1,TY_STRING)); else Push(NVALUE(0));
      break;
    case TY_CODE:
      return v1;
  }
  return ptr+n+n+2;
}

static void v_data(Value v1,Value v2) {
  const unsigned char*s;
  int i;
  Value v;
  if(v1.t!=TY_STRING && v1.t!=TY_LEVELSTRING) Throw("Type mismatch");
  s=value_string_ptr(v1);
  if(v2.t==TY_NUMBER) {
    for(;;) {
      s+=strcspn(s,"\x1F\x1E");
      if(!*s) return;
      if(*s==31) {
        s++;
        if(*s) s++;
      } else {
        s++;
        if(!v2.u) break;
        v2.u--;
      }
    }
    while(s && *s && *s!='\\') {
      if(*s=='_') {
        v.t=TY_MARK;
        v.u=0;
        s++;
      } else if(*s=='$') {
        s++;
        v.t=TY_CLASS;
        i=strcspn(s,";\\");
        for(v.u=1;v.u<0x4000;v.u++) {
          if(classes[v.u] && !(classes[v.u]->cflags&(CF_NOCLASS2|CF_GROUP)) && i==strlen(classes[v.u]->name) && !strncmp(s,classes[v.u]->name,i)) {
            s+=i;
            break;
          }
        }
      } else {
        v.t=TY_NUMBER;
        v.u=strtol(s,(char**)&s,10);
      }
      StackReq(0,1);
      Push(v);
      if(*s=='\\') break;
      if(*s!=';' && *s!='\\') Throw("Invalid string data");
      if(*s==';') s++; else break;
    }
  } else if(v2.t==TY_MESSAGE && v2.u==MSG_KEY) {
    v.t=TY_NUMBER;
    v.u=0;
    for(;;) {
      s+=strcspn(s,"\x1F\x10");
      if(!*s) return;
      if(*s==31) {
        s++;
        if(*s) s++;
      } else {
        s++;
        StackReq(0,1);
        if(*s) v.u=*s++;
        Push(v);
      }
    }
  } else {
    Throw("Type mismatch");
  }
}

// Here is where the execution of a Free Hero Mesh bytecode subroutine is executed.
#define NoIgnore() do{ changed=1; }while(0)
#define GetVariableOf(a,b) (i=v_object(Pop()),i==VOIDLINK?NVALUE(0):b(objects[i]->a))
#define GetVariableOrAttributeOf(a,b) (t2=Pop(),t2.t==TY_CLASS?NVALUE(classes[t2.u]->a):(i=v_object(t2),i==VOIDLINK?NVALUE(0):b(objects[i]->a)))
#define Numeric(a) do{ if((a).t!=TY_NUMBER) Throw("Type mismatch"); }while(0)
#define DivideBy(a) do{ Numeric(a); if(!(a).u) Throw("Division by zero"); }while(0)

    case OP_COLOC_C: StackReq(2,1); t1=Pop(); t2=Pop(); i=colocation(v_object(t1),v_object(t2)); Push(NVALUE(i)); break;
    case OP_COMPATIBLE: StackReq(0,1); if(classes[o->class]->cflags&CF_COMPATIBLE) Push(NVALUE(1)); else Push(NVALUE(0)); break;
    case OP_COMPATIBLE_C: StackReq(1,1); GetClassFlagOf(CF_COMPATIBLE); break;
    case OP_COPYARRAY: NoIgnore(); StackReq(2,0); t2=Pop(); t1=Pop(); v_copy_array(t1,t2); break;
    case OP_COUNT: StackReq(1,2); i=v_count(); Push(NVALUE(i)); break;
    case OP_CREATE: NoIgnore(); StackReq(5,1); t5=Pop(); t4=Pop(); t3=Pop(); t2=Pop(); t1=Pop(); Push(v_create(obj,t1,t2,t3,t4,t5)); break;
    case OP_CREATE_D: NoIgnore(); StackReq(5,0); t5=Pop(); t4=Pop(); t3=Pop(); t2=Pop(); t1=Pop(); v_create(obj,t1,t2,t3,t4,t5); break;
    case OP_DATA: StackReq(2,1); t2=Pop(); t1=Pop(); v_data(t1,t2); break;
    case OP_DELINVENTORY: StackReq(2,0); t2=Pop(); t1=Pop(); v_delete_inventory(t1,t2); break;
    case OP_DELTA: StackReq(2,1); t2=Pop(); Numeric(t2); t1=Pop(); Numeric(t1); Push(NVALUE(t1.u>t2.u?t1.u-t2.u:t2.u-t1.u)); break;
    case OP_DENSITY: StackReq(0,1); Push(NVALUE(o->density)); break;
    case OP_DENSITY_C: StackReq(1,1); Push(GetVariableOrAttributeOf(density,NVALUE)); break;
    case OP_DENSITY_E: NoIgnore(); StackReq(1,0); t1=Pop(); Numeric(t1); change_density(obj,t1.s); break;
    case OP_DENSITY_E16: NoIgnore(); StackReq(1,0); t1=Pop(); Numeric(t1); change_density(obj,t1.s&0xFFFF); break;
    case OP_DENSITY_EC: NoIgnore(); StackReq(2,0); t1=Pop(); Numeric(t1); change_density(v_object(Pop()),t1.s); break;