Add support for zmpop (#605)

src/commands.rs

@@ -813,6 +813,18 @@ implement_commands! {
         cmd("ZPOPMIN").arg(key).arg(count)
     }
 
+    /// Removes and returns up to count members with the highest scores, 
+    /// from the first non-empty sorted set in the provided list of key names.
+    fn zmpop_max<K: ToRedisArgs>(keys: &'a [K], count: isize) {
+        cmd("ZMPOP").arg(keys.len()).arg(keys).arg("MAX").arg("COUNT").arg(count)
+    }
+
+    /// Removes and returns up to count members with the lowest scores, 
+    /// from the first non-empty sorted set in the provided list of key names.
+    fn zmpop_min<K: ToRedisArgs>(keys: &'a [K], count: isize) {
+        cmd("ZMPOP").arg(keys.len()).arg(keys).arg("MIN").arg("COUNT").arg(count)
+    }
+
     /// Return up to count random members in a sorted set (or 1 if `count == None`)
     fn zrandmember<K: ToRedisArgs>(key: K, count: Option<isize>) {
         cmd("ZRANDMEMBER").arg(key).arg(count)

src/connection.rs

@@ -867,11 +867,7 @@ impl ConnectionLike for Connection {
             }
         }
 
-        if let Some(err) = first_err {
-            Err(err)
-        } else {
-            Ok(rv)
-        }
+        first_err.map_or(Ok(rv), Err)
     }
 
     fn get_db(&self) -> i64 {

src/streams.rs

@@ -190,7 +190,7 @@ impl ToRedisArgs for StreamReadOptions {
 
         if let Some(ref group) = self.group {
             // noack is only available w/ xreadgroup
-            if let Some(true) = self.noack {
+            if self.noack == Some(true) {
                 out.write_arg(b"NOACK");
             }
 

src/types.rs

@@ -1263,7 +1263,7 @@ impl FromRedisValue for InfoDict {
 
 impl<T: FromRedisValue> FromRedisValue for Option<T> {
     fn from_redis_value(v: &Value) -> RedisResult<Option<T>> {
-        if let Value::Nil = *v {
+        if *v == Value::Nil {
             return Ok(None);
         }
         Ok(Some(from_redis_value(v)?))