From 50b47dce4b3f881f69c3287b868e7b1d98d77bc1 Mon Sep 17 00:00:00 2001
From: Emir Pasic <emirpasic83@gmail.com>
Date: Mon, 6 Mar 2017 01:28:09 +0100
Subject: [PATCH] - JSON serialization for all sets

---
 sets/hashset/hashset_test.go  | 26 ++++++++++++++++++++++++++
 sets/hashset/serialization.go | 31 +++++++++++++++++++++++++++++++
 sets/treeset/serialization.go | 31 +++++++++++++++++++++++++++++++
 sets/treeset/treeset_test.go  | 26 ++++++++++++++++++++++++++
 4 files changed, 114 insertions(+)
 create mode 100644 sets/hashset/serialization.go
 create mode 100644 sets/treeset/serialization.go

diff --git a/sets/hashset/hashset_test.go b/sets/hashset/hashset_test.go
index b868631..280a6b3 100644
--- a/sets/hashset/hashset_test.go
+++ b/sets/hashset/hashset_test.go
@@ -62,6 +62,32 @@ func TestSetRemove(t *testing.T) {
 	}
 }
 
+func TestSetSerialization(t *testing.T) {
+	set := New()
+	set.Add("a", "b", "c")
+
+	var err error
+	assert := func() {
+		if actualValue, expectedValue := set.Size(), 3; actualValue != expectedValue {
+			t.Errorf("Got %v expected %v", actualValue, expectedValue)
+		}
+		if actualValue := set.Contains("a", "b", "c"); actualValue != true {
+			t.Errorf("Got %v expected %v", actualValue, true)
+		}
+		if err != nil {
+			t.Errorf("Got error %v", err)
+		}
+	}
+
+	assert()
+
+	json, err := set.ToJSON()
+	assert()
+
+	err = set.FromJSON(json)
+	assert()
+}
+
 func benchmarkContains(b *testing.B, set *Set, size int) {
 	for i := 0; i < b.N; i++ {
 		for n := 0; n < size; n++ {
diff --git a/sets/hashset/serialization.go b/sets/hashset/serialization.go
new file mode 100644
index 0000000..af7bfe8
--- /dev/null
+++ b/sets/hashset/serialization.go
@@ -0,0 +1,31 @@
+// 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 hashset
+
+import (
+	"encoding/json"
+	"github.com/emirpasic/gods/containers"
+)
+
+func assertSerializationImplementation() {
+	var _ containers.JSONSerializer = (*Set)(nil)
+	var _ containers.JSONDeserializer = (*Set)(nil)
+}
+
+// ToJSON outputs the JSON representation of list's elements.
+func (set *Set) ToJSON() ([]byte, error) {
+	return json.Marshal(set.Values())
+}
+
+// FromJSON populates list's elements from the input JSON representation.
+func (set *Set) FromJSON(data []byte) error {
+	elements := []interface{}{}
+	err := json.Unmarshal(data, &elements)
+	if err == nil {
+		set.Clear()
+		set.Add(elements...)
+	}
+	return err
+}
diff --git a/sets/treeset/serialization.go b/sets/treeset/serialization.go
new file mode 100644
index 0000000..10b1599
--- /dev/null
+++ b/sets/treeset/serialization.go
@@ -0,0 +1,31 @@
+// 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 treeset
+
+import (
+	"encoding/json"
+	"github.com/emirpasic/gods/containers"
+)
+
+func assertSerializationImplementation() {
+	var _ containers.JSONSerializer = (*Set)(nil)
+	var _ containers.JSONDeserializer = (*Set)(nil)
+}
+
+// ToJSON outputs the JSON representation of list's elements.
+func (set *Set) ToJSON() ([]byte, error) {
+	return json.Marshal(set.Values())
+}
+
+// FromJSON populates list's elements from the input JSON representation.
+func (set *Set) FromJSON(data []byte) error {
+	elements := []interface{}{}
+	err := json.Unmarshal(data, &elements)
+	if err == nil {
+		set.Clear()
+		set.Add(elements...)
+	}
+	return err
+}
diff --git a/sets/treeset/treeset_test.go b/sets/treeset/treeset_test.go
index 881adc2..0f4b667 100644
--- a/sets/treeset/treeset_test.go
+++ b/sets/treeset/treeset_test.go
@@ -327,6 +327,32 @@ func TestSetIteratorLast(t *testing.T) {
 	}
 }
 
+func TestSetSerialization(t *testing.T) {
+	set := NewWithStringComparator()
+	set.Add("a", "b", "c")
+
+	var err error
+	assert := func() {
+		if actualValue, expectedValue := set.Size(), 3; actualValue != expectedValue {
+			t.Errorf("Got %v expected %v", actualValue, expectedValue)
+		}
+		if actualValue := set.Contains("a", "b", "c"); actualValue != true {
+			t.Errorf("Got %v expected %v", actualValue, true)
+		}
+		if err != nil {
+			t.Errorf("Got error %v", err)
+		}
+	}
+
+	assert()
+
+	json, err := set.ToJSON()
+	assert()
+
+	err = set.FromJSON(json)
+	assert()
+}
+
 func benchmarkContains(b *testing.B, set *Set, size int) {
 	for i := 0; i < b.N; i++ {
 		for n := 0; n < size; n++ {