add basic records

core/types.go

@@ -21,6 +21,7 @@ const (
 	TypeComposite
 	TypeInner
 	TypeNamed
+	TypeRecord
 )
 
 func (t Type) String() string {
@@ -521,3 +522,56 @@ func (s *NamedSignature) Equal(t TypeSignature) bool {
 func (s *NamedSignature) String() string {
 	return s.Name
 }
+
+type RecordSignature struct {
+	Entries map[string]TypeSignature
+}
+
+func (*RecordSignature) Type() Type {
+	return TypeRecord
+}
+
+func (s *RecordSignature) Contains(t TypeSignature) bool {
+	if t.Type() != TypeRecord {
+		return false
+	}
+
+	rs := t.(*RecordSignature)
+
+	/*
+		// not quite sure about this one
+		if len(s.Entries) != len(rs.Entries) {
+			return false
+		}
+	*/
+
+	for k, v := range s.Entries {
+		is, ok := rs.Entries[k]
+		if !ok {
+			return false
+		}
+
+		if !v.Contains(is) {
+			return false
+		}
+	}
+
+	return true
+}
+
+func (s *RecordSignature) Equal(t TypeSignature) bool {
+	return s.Contains(t) && t.Contains(s)
+}
+
+func (s *RecordSignature) String() string {
+	b := strings.Builder{}
+	b.WriteString("(")
+
+	for name, kind := range s.Entries {
+		b.WriteString(fmt.Sprintf("%s: %s, ", name, kind))
+	}
+
+	b.WriteString(")")
+
+	return b.String()
+}

core/values.go

@@ -22,7 +22,7 @@ const (
 	ObjectValueType
 	FunctionValueType
 	BuiltinFunctionValueType
-	VariableValueType
+	RecordValueType
 )
 
 func (v ValueType) String() string {
@@ -47,8 +47,8 @@ func (v ValueType) String() string {
 		return "function"
 	case BuiltinFunctionValueType:
 		return "builtin function"
-	case VariableValueType:
+	case RecordValueType:
-		return "variable"
+		return "record"
 	}
 
 	return "undefined"
@@ -767,3 +767,59 @@ func (v *BuiltinFunctionValue) Clone() Value {
 		v.Constant,
 	}
 }
+
+type RecordValue struct {
+	Entries map[string]Value
+}
+
+func (v *RecordValue) Type() ValueType {
+	return RecordValueType
+}
+
+func (v *RecordValue) String() string {
+	return ""
+}
+
+func (v *RecordValue) DebugString() string {
+	return v.String()
+}
+
+func (v *RecordValue) Clone() Value {
+	return &RecordValue{
+		v.Entries,
+	}
+}
+
+func (v *RecordValue) Equals(other Value) bool {
+	if other.Type() != RecordValueType {
+		return false
+	}
+
+	r := other.(*RecordValue)
+
+	if len(r.Entries) != len(v.Entries) {
+		return false
+	}
+
+	for key, val := range v.Entries {
+		oth, ok := r.Entries[key]
+		if !ok {
+			return false
+		}
+
+		if !val.Equals(oth) {
+			return false
+		}
+	}
+
+	return true
+}
+
+func (v *RecordValue) Get(key string) (Value, error) {
+	val, ok := v.Entries[key]
+	if !ok {
+		return nil, errors.New(fmt.Sprintf("record has no property \"%s\"", key))
+	}
+
+	return val, nil
+}