- hash map (de)serialization

maps/hashmap/hashmap_test.go

@@ -118,6 +118,37 @@ func TestMapRemove(t *testing.T) {
 	}
 }
 
+func TestMapSerialization(t *testing.T) {
+	m := New()
+	m.Put("a", 1.0)
+	m.Put("b", 2.0)
+	m.Put("c", 3.0)
+
+	var err error
+	assert := func() {
+		if actualValue, expectedValue := m.Keys(), []interface{}{"a", "b", "c"}; !sameElements(actualValue, expectedValue) {
+			t.Errorf("Got %v expected %v", actualValue, expectedValue)
+		}
+		if actualValue, expectedValue := m.Values(), []interface{}{1.0, 2.0, 3.0}; !sameElements(actualValue, expectedValue) {
+			t.Errorf("Got %v expected %v", actualValue, expectedValue)
+		}
+		if actualValue, expectedValue := m.Size(), 3; actualValue != expectedValue {
+			t.Errorf("Got %v expected %v", actualValue, expectedValue)
+		}
+		if err != nil {
+			t.Errorf("Got error %v", err)
+		}
+	}
+
+	assert()
+
+	json, err := m.ToJSON()
+	assert()
+
+	err = m.FromJSON(json)
+	assert()
+}
+
 func sameElements(a []interface{}, b []interface{}) bool {
 	if len(a) != len(b) {
 		return false

maps/hashmap/serialization.go

@@ -0,0 +1,38 @@
+// Copyright (c) 2015, Emir Pasic. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package hashmap
+
+import (
+	"encoding/json"
+	"github.com/emirpasic/gods/containers"
+	"github.com/emirpasic/gods/utils"
+)
+
+func assertSerializationImplementation() {
+	var _ containers.JSONSerializer = (*Map)(nil)
+	var _ containers.JSONDeserializer = (*Map)(nil)
+}
+
+// ToJSON outputs the JSON representation of list's elements.
+func (m *Map) ToJSON() ([]byte, error) {
+	elements := make(map[string]interface{})
+	for key, value := range m.m {
+		elements[utils.ToString(key)] = value
+	}
+	return json.Marshal(&elements)
+}
+
+// FromJSON populates list's elements from the input JSON representation.
+func (m *Map) FromJSON(data []byte) error {
+	elements := make(map[string]interface{})
+	err := json.Unmarshal(data, &elements)
+	if err == nil {
+		m.Clear()
+		for key, value := range elements {
+			m.m[key] = value
+		}
+	}
+	return err
+}