Add a fast path for Float and Fixnum ranges for Range#max and Range#min

If no block is given and the Range has Fixnum or Float endpoints, do not iterate with
each and instead compare the endpoints directly. This implementation passes all of
the applicable specs from Ruby Spec.

1 files changed, 40 insertions, 0 deletions

diff --git a/mrbgems/mruby-range-ext/mrblib/range.rb b/mrbgems/mruby-range-ext/mrblib/range.rb
index de7925ba7..e09b2d096 100644
--- a/mrbgems/mruby-range-ext/mrblib/range.rb
+++ b/mrbgems/mruby-range-ext/mrblib/range.rb
@@ -25,4 +25,44 @@ class Range
     end
     ary
   end
+
+  def max(&block)
+    val = self.first
+    last = self.last
+    return super if block
+
+    # fast path for numerics
+    if (val.kind_of?(Fixnum) || val.kind_of?(Float)) && (last.kind_of?(Fixnum) || last.kind_of?(Float))
+      raise TypeError if exclude_end? && !last.kind_of?(Fixnum)
+      return nil if val > last
+      return nil if val == last && exclude_end?
+
+      max = last
+      max -= 1 if exclude_end?
+      return max
+    end
+
+    # delegate to Enumerable
+    super
+  end
+
+  def min(&block)
+    val = self.first
+    last = self.last
+    return super if block
+
+    # fast path for numerics
+    if (val.kind_of?(Fixnum) || val.kind_of?(Float)) && (last.kind_of?(Fixnum) || last.kind_of?(Float))
+      raise TypeError if exclude_end? && !last.kind_of?(Fixnum)
+      return nil if val > last
+      return nil if val == last && exclude_end?
+
+      min = val
+      min -= 1 if exclude_end?
+      return min
+    end
+
+    # delegate to Enumerable
+    super
+  end
 end