feat: add Float64Map (#605)

Add a Float64Map helper which can be used to convert a
HGETALL responses to a map[string]float64.

redis/reply.go

@@ -476,6 +476,36 @@ func Int64Map(result interface{}, err error) (map[string]int64, error) {
 	return m, nil
 }
 
+// Float64Map is a helper that converts an array of strings (alternating key, value)
+// into a map[string]float64. The HGETALL commands return replies in this format.
+// Requires an even number of values in result.
+func Float64Map(result interface{}, err error) (map[string]float64, error) {
+	values, err := Values(result, err)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(values)%2 != 0 {
+		return nil, fmt.Errorf("redigo: Float64Map expects even number of values result, got %d", len(values))
+	}
+
+	m := make(map[string]float64, len(values)/2)
+	for i := 0; i < len(values); i += 2 {
+		key, ok := values[i].([]byte)
+		if !ok {
+			return nil, fmt.Errorf("redigo: Float64Map key[%d] not a bulk string value, got %T", i, values[i])
+		}
+
+		value, err := Float64(values[i+1], nil)
+		if err != nil {
+			return nil, err
+		}
+
+		m[string(key)] = value
+	}
+	return m, nil
+}
+
 // Positions is a helper that converts an array of positions (lat, long)
 // into a [][2]float64. The GEOPOS command returns replies in this format.
 func Positions(result interface{}, err error) ([]*[2]float64, error) {

redis/reply_test.go

@@ -123,6 +123,11 @@ var replyTests = []struct {
 		ve(redis.Float64(nil, nil)),
 		ve(float64(0.0), redis.ErrNil),
 	},
+	{
+		"float64Map([[]byte, []byte])",
+		ve(redis.Float64Map([]interface{}{[]byte("key1"), []byte("1.234"), []byte("key2"), []byte("5.678")}, nil)),
+		ve(map[string]float64{"key1": 1.234, "key2": 5.678}, nil),
+	},
 	{
 		"uint64(1)",
 		ve(redis.Uint64(int64(1), nil)),