Support for list range storage method

lib/Myriad/Role/Storage.pm

@@ -351,6 +351,7 @@ our @READ_METHODS = qw(
     hash_exists
     hash_count
     hash_as_list
+    list_range
     orderedset_member_count
     orderedset_members
     unorderedset_is_member
@@ -482,6 +483,26 @@ suitable for assigning to a hash.
 
 method hash_as_list;
 
+=head2 list_range
+
+Takes the following parameters:
+
+=over 4
+
+=item * key
+
+=item * start index (from 0), use negative values to indicate distance from end of list (-1 being the last element)
+
+=item * end index (from 0), as above
+
+=back
+
+Returns a L<Future> which will resolve to a list of values from the list.
+
+=cut
+
+method list_range;
+
 =head2 orderedset_member_count
 
 Returns the count of members that have scores within the range passed from an orderedset structure

lib/Myriad/Storage/Implementation/Memory.pm

@@ -413,6 +413,15 @@ async method hash_as_list : Defer ($k) {
     return $data{$k}->%*;
 }
 
+async method list_range : Defer ($k, $start = 0, $end = -1) {
+    my $len = 0 + $data{$k}->@*
+        or return [ ];
+    # Handle negative values as offset from end (-1 being last element)
+    $start = $len - $start if $start < 0;
+    $end = $len - $end if $end < 0;
+    return [ $data{$k}->@*[$start .. $end] ];
+}
+
 =head2 orderedset_add
 
 Takes the following parameters:

lib/Myriad/Storage/Implementation/Redis.pm

@@ -215,6 +215,10 @@ async method watch_keyspace ($keyspace) {
     });
 }
 
+async method list_range ($k, $start = 0, $end = -1) {
+    await $redis->lrange($self->apply_prefix($k), $start, $end);
+}
+
 =head2 push
 
 Takes the following parameters: