From caf3bb2de8c0e5e54b8e3d56c557c1d7f5cc40de Mon Sep 17 00:00:00 2001
From: Jeromy <why@ipfs.io>
Date: Thu, 1 Sep 2016 15:46:36 -0700
Subject: [PATCH] add some more helper functions to ease integration into
 go-ipfs

---
 cid.go | 19 +++++++++++++++++++
 set.go |  9 +++++++++
 2 files changed, 28 insertions(+)

diff --git a/cid.go b/cid.go
index cf693a9..a46ddd9 100644
--- a/cid.go
+++ b/cid.go
@@ -145,3 +145,22 @@ func (c *Cid) Equals(o *Cid) bool {
 		c.version == o.version &&
 		bytes.Equal(c.hash, o.hash)
 }
+
+func (c *Cid) UnmarshalJSON(b []byte) error {
+	if len(b) < 2 {
+		return fmt.Errorf("invalid cid json blob")
+	}
+	out, err := Decode(string(b[1 : len(b)-1]))
+	if err != nil {
+		return err
+	}
+
+	c.version = out.version
+	c.hash = out.hash
+	c.codec = out.codec
+	return nil
+}
+
+func (c *Cid) MarshalJSON() ([]byte, error) {
+	return []byte(fmt.Sprintf("\"%s\"", c.String())), nil
+}
diff --git a/set.go b/set.go
index ec97a1f..a237ae3 100644
--- a/set.go
+++ b/set.go
@@ -33,3 +33,12 @@ func (s *Set) Keys() []*Cid {
 	}
 	return out
 }
+
+func (s *Set) Visit(c *Cid) bool {
+	if !s.Has(c) {
+		s.Add(c)
+		return true
+	}
+
+	return false
+}