Convert Set and FrozenSet into pointer types

Author: ncw

marshal/marshal.go

@@ -211,15 +211,11 @@ func ReadObject(r io.Reader) (obj py.Object, err error) {
 			return py.NewListFromItems(tuple), nil
 		}
 
-		set := make(py.Set, len(tuple))
-		for _, obj := range tuple {
-			set[obj] = py.SetValue{}
-		}
 		switch Type {
 		case TYPE_SET:
-			return py.Set(set), nil
+			return py.NewSetFromItems(tuple), nil
 		case TYPE_FROZENSET:
-			return py.FrozenSet(set), nil
+			return py.NewFrozenSetFromItems(tuple), nil
 		}
 	case TYPE_DICT:
 		// FIXME should be py.Dict

py/set.go

@@ -1,23 +1,71 @@
 // Set and FrozenSet types
+//
+// FIXME preliminary implementation only - doesn't work properly!
 
 package py
 
 var SetType = NewType("set", "set() -> new empty set object\nset(iterable) -> new set object\n\nBuild an unordered collection of unique elements.")
 
 type SetValue struct{}
 
-type Set map[Object]SetValue
+type Set struct {
+	items map[Object]SetValue
+}
 
 // Type of this Set object
-func (o Set) Type() *Type {
+func (o *Set) Type() *Type {
 	return SetType
 }
 
+// Make a new empty set
+func NewSet() *Set {
+	return &Set{
+		items: make(map[Object]SetValue),
+	}
+}
+
+// Make a new empty set with capacity for n items
+func NewSetWithCapacity(n int) *Set {
+	return &Set{
+		items: make(map[Object]SetValue, n),
+	}
+}
+
+// Make a new set with the items passed in
+func NewSetFromItems(items []Object) *Set {
+	s := NewSetWithCapacity(len(items))
+	for _, item := range items {
+		s.items[item] = SetValue{}
+	}
+	return s
+}
+
+// Add an item to the set
+func (s *Set) Add(item Object) {
+	s.items[item] = SetValue{}
+}
+
 var FrozenSetType = NewType("frozenset", "frozenset() -> empty frozenset object\nfrozenset(iterable) -> frozenset object\n\nBuild an immutable unordered collection of unique elements.")
 
-type FrozenSet map[Object]SetValue
+type FrozenSet struct {
+	Set
+}
 
 // Type of this FrozenSet object
-func (o FrozenSet) Type() *Type {
+func (o *FrozenSet) Type() *Type {
 	return FrozenSetType
 }
+
+// Make a new empty frozen set
+func NewFrozenSet() *FrozenSet {
+	return &FrozenSet{
+		Set: *NewSet(),
+	}
+}
+
+// Make a new set with the items passed in
+func NewFrozenSetFromItems(items []Object) *FrozenSet {
+	return &FrozenSet{
+		Set: *NewSetFromItems(items),
+	}
+}