From 754c11ab7f0ba24a6c977daac0d35a5b2c272ef7 Mon Sep 17 00:00:00 2001
From: Vladimir Mihailenco <vladimir.webdev@gmail.com>
Date: Tue, 7 Oct 2014 13:54:43 +0300
Subject: [PATCH] Add bitpos command.

---
 commands.go      | 16 ++++++++++++++++
 commands_test.go | 41 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/commands.go b/commands.go
index 2d2817f..c43fcd2 100644
--- a/commands.go
+++ b/commands.go
@@ -361,6 +361,22 @@ func (c *commandable) BitOpNot(destKey string, key string) *IntCmd {
 	return c.bitOp("NOT", destKey, key)
 }
 
+func (c *commandable) BitPos(key string, bit int64, pos ...int64) *IntCmd {
+	args := []string{"BITPOS", key, formatInt(bit)}
+	switch len(pos) {
+	case 0:
+	case 1:
+		args = append(args, formatInt(pos[0]))
+	case 2:
+		args = append(args, formatInt(pos[0]), formatInt(pos[1]))
+	default:
+		panic("too many arguments")
+	}
+	cmd := NewIntCmd(args...)
+	c.Process(cmd)
+	return cmd
+}
+
 func (c *commandable) Decr(key string) *IntCmd {
 	cmd := NewIntCmd("DECR", key)
 	c.Process(cmd)
diff --git a/commands_test.go b/commands_test.go
index 7ef9408..e87845a 100644
--- a/commands_test.go
+++ b/commands_test.go
@@ -668,6 +668,47 @@ var _ = Describe("Commands", func() {
 			Expect(get.Val()).To(Equal("\xff"))
 		})
 
+		It("should BitPos", func() {
+			err := client.Set("mykey", "\xff\xf0\x00", 0).Err()
+			Expect(err).NotTo(HaveOccurred())
+
+			pos, err := client.BitPos("mykey", 0).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(pos).To(Equal(int64(12)))
+
+			pos, err = client.BitPos("mykey", 1).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(pos).To(Equal(int64(0)))
+
+			pos, err = client.BitPos("mykey", 0, 2).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(pos).To(Equal(int64(16)))
+
+			pos, err = client.BitPos("mykey", 1, 2).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(pos).To(Equal(int64(-1)))
+
+			pos, err = client.BitPos("mykey", 0, -1).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(pos).To(Equal(int64(16)))
+
+			pos, err = client.BitPos("mykey", 1, -1).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(pos).To(Equal(int64(-1)))
+
+			pos, err = client.BitPos("mykey", 0, 2, 1).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(pos).To(Equal(int64(-1)))
+
+			pos, err = client.BitPos("mykey", 0, 0, -3).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(pos).To(Equal(int64(-1)))
+
+			pos, err = client.BitPos("mykey", 0, 0, 0).Result()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(pos).To(Equal(int64(-1)))
+		})
+
 		It("should Decr", func() {
 			set := client.Set("key", "10", 0)
 			Expect(set.Err()).NotTo(HaveOccurred())