Merge pull request #456 from ayrton/zrangebylex

Add support for limit in zrangebylex

Author: yaauie

lib/redis.rb

@@ -1588,6 +1588,38 @@ def zremrangebyrank(key, start, stop)
     end
   end
 
+  # Return a range of members with the same score in a sorted set, by lexicographical ordering
+  #
+  # @example Retrieve members matching a
+  #   redis.zrangebylex("zset", "[a", "[a\xff")
+  #     # => ["aaren", "aarika", "abagael", "abby"]
+  # @example Retrieve the first 2 members matching a
+  #   redis.zrangebylex("zset", "[a", "[a\xff", :limit => [0, 2])
+  #     # => ["aaren", "aarika"]
+  #
+  # @param [String] key
+  # @param [String] min
+  #   - inclusive minimum is specified by prefixing `(`
+  #   - exclusive minimum is specified by prefixing `[`
+  # @param [String] max
+  #   - inclusive maximum is specified by prefixing `(`
+  #   - exclusive maximum is specified by prefixing `[`
+  # @param [Hash] options
+  #   - `:limit => [offset, count]`: skip `offset` members, return a maximum of
+  #   `count` members
+  #
+  # @return [Array<String>, Array<[String, Float]>]
+  def zrangebylex(key, min, max, options = {})
+    args = []
+
+    limit = options[:limit]
+    args.concat(["LIMIT"] + limit) if limit
+
+    synchronize do |client|
+      client.call([:zrangebylex, key, min, max] + args)
+    end
+  end
+
   # Return a range of members in a sorted set, by score.
   #
   # @example Retrieve members with score `>= 5` and `< 100`

test/commands_on_sorted_sets_test.rb

@@ -8,6 +8,20 @@ class TestCommandsOnSortedSets < Test::Unit::TestCase
   include Helper::Client
   include Lint::SortedSets
 
+  def test_zrangebylex
+    target_version "2.8.9" do
+      r.zadd "foo", 0, "aaren"
+      r.zadd "foo", 0, "abagael"
+      r.zadd "foo", 0, "abby"
+      r.zadd "foo", 0, "abbygail"
+
+      assert_equal ["aaren", "abagael", "abby", "abbygail"], r.zrangebylex("foo", "[a", "[a\xff")
+      assert_equal ["aaren", "abagael"], r.zrangebylex("foo", "[a", "[a\xff", :limit => [0, 2])
+      assert_equal ["abby", "abbygail"], r.zrangebylex("foo", "(abb", "(abb\xff")
+      assert_equal ["abbygail"], r.zrangebylex("foo", "(abby", "(abby\xff")
+    end
+  end
+
   def test_zcount
     r.zadd "foo", 1, "s1"
     r.zadd "foo", 2, "s2"