From 115e15d12b389af16153015f0b5906bf14048867 Mon Sep 17 00:00:00 2001
From: Jeremy Evans <code@jeremyevans.net>
Date: Mon, 17 Jun 2019 14:23:24 -0700
Subject: [PATCH] Implement SortedSet#{min,max,minmax,sum}

This results in a huge speedup for large sets.

Implements [Misc #15925]
---
 benchmark/set_min_max_sum.yml |  8 ++++++++
 lib/set.rb                    | 16 ++++++++++++++++
 test/test_set.rb              |  4 ++++
 3 files changed, 28 insertions(+)
 create mode 100644 benchmark/set_min_max_sum.yml

diff --git a/benchmark/set_min_max_sum.yml b/benchmark/set_min_max_sum.yml
new file mode 100644
index 0000000000..0a4678bdbc
--- /dev/null
+++ b/benchmark/set_min_max_sum.yml
@@ -0,0 +1,8 @@
+prelude: |
+  require 'set'
+  set = SortedSet.new((0..1000).sort{rand})
+benchmark:
+  min: set.min
+  max: set.max
+  minmax: set.minmax
+  sum: set.sum
diff --git a/lib/set.rb b/lib/set.rb
index 921f18f97b..421d4dfc88 100644
--- a/lib/set.rb
+++ b/lib/set.rb
@@ -738,6 +738,22 @@ def replace(enum)
               super
             end
 
+            def min
+              to_a.first
+            end
+
+            def max
+              to_a.last
+            end
+
+            def minmax
+              [min, max]
+            end
+
+            def sum
+              to_a.sum
+            end
+
             def add(o)
               o.respond_to?(:<=>) or raise ArgumentError, "value must respond to <=>"
               @keys = nil
diff --git a/test/test_set.rb b/test/test_set.rb
index b20920e63e..5f5bff58de 100644
--- a/test/test_set.rb
+++ b/test/test_set.rb
@@ -799,6 +799,10 @@ def test_sortedset
     s = SortedSet[4,5,3,1,2]
 
     assert_equal([1,2,3,4,5], s.to_a)
+    assert_equal(1, s.min)
+    assert_equal(5, s.max)
+    assert_equal([1,5], s.minmax)
+    assert_equal(15, s.sum)
 
     prev = nil
     s.each { |o| assert(prev < o) if prev; prev = o }
-- 
2.21.0