vm/tagged.hpp

   1 namespace factor
   2 {
   3
   4 template<typename Type> cell tag(Type *value)
   5 {
   6         return RETAG(value,tag_for(Type::type_number));
   7 }
   8
   9 inline static cell tag_dynamic(object *value)
  10 {
  11         return RETAG(value,tag_for(value->h.hi_tag()));
  12 }
  13
  14 template<typename Type>
  15 struct tagged
  16 {
  17         cell value_;
  18
  19         cell value() const { return value_; }
  20         Type *untagged() const { return (Type *)(UNTAG(value_)); }
  21
  22         cell type() const {
  23                 cell tag = TAG(value_);
  24                 if(tag == OBJECT_TYPE)
  25                         return untagged()->h.hi_tag();
  26                 else
  27                         return tag;
  28         }
  29
  30         bool type_p(cell type_) const
  31         {
  32                 return type() == type_;
  33         }
  34
  35         bool type_p() const
  36         {
  37                 if(Type::type_number == TYPE_COUNT)
  38                         return true;
  39                 else
  40                         return type_p(Type::type_number);
  41         }
  42
  43         Type *untag_check(factor_vm *parent) const {
  44                 if(!type_p())
  45                         parent->type_error(Type::type_number,value_);
  46                 return untagged();
  47         }
  48
  49         explicit tagged(cell tagged) : value_(tagged) {
  50 #ifdef FACTOR_DEBUG
  51                 assert(type_p());
  52 #endif
  53         }
  54
  55         explicit tagged(Type *untagged) : value_(factor::tag(untagged)) {
  56 #ifdef FACTOR_DEBUG
  57                 assert(type_p());
  58 #endif
  59         }
  60
  61         Type *operator->() const { return untagged(); }
  62         cell *operator&() const { return &value_; }
  63
  64         const tagged<Type> &operator=(const Type *x) { value_ = tag(x); return *this; }
  65         const tagged<Type> &operator=(const cell &x) { value_ = x; return *this; }
  66
  67         bool operator==(const tagged<Type> &x) { return value_ == x.value_; }
  68         bool operator!=(const tagged<Type> &x) { return value_ != x.value_; }
  69
  70         template<typename NewType> tagged<NewType> as() { return tagged<NewType>(value_); }
  71 };
  72
  73 template<typename Type> Type *factor_vm::untag_check(cell value)
  74 {
  75         return tagged<Type>(value).untag_check(this);
  76 }
  77
  78 template<typename Type> Type *untag(cell value)
  79 {
  80         return tagged<Type>(value).untagged();
  81 }
  82
  83 }