fbernier · August 29, 2015 13:56 · Feb 26, 2014 · Feb 26, 2014 · Feb 26, 2014 · Feb 26, 2014
diff --git a/lazy.rb b/lazy.rb
@@ -1,6 +1,8 @@
 # Enumerator#lazy is very slow and should only be used when iterating over large/infinite collections
 # where you know you are going to get your results quite early in the iteration.
 
+# This benchmark is purposely made to advantage the lazy version, without much success.
+
 require 'benchmark/ips'
 
 class Enumerator::Lazy

diff --git a/lazy.rb b/lazy.rb
@@ -1,5 +1,5 @@
-# Enumerator#lazy is quite slow and should only be used when iterating over large collections
-# where you need few results and you know you are going to get them quite early in the iteration.
+# Enumerator#lazy is very slow and should only be used when iterating over large/infinite collections
+# where you know you are going to get your results quite early in the iteration.
 
 require 'benchmark/ips'
 

diff --git a/lazy.rb b/lazy.rb
@@ -1,5 +1,5 @@
 # Enumerator#lazy is quite slow and should only be used when iterating over large collections
-where you need few results and you know you are going to get them quite early in the iteration.
+# where you need few results and you know you are going to get them quite early in the iteration.
 
 require 'benchmark/ips'
 

diff --git a/lazy.rb b/lazy.rb
@@ -1,4 +1,5 @@
-# Enumerator#lazy is quite slow and should only be used when iterating over large collections where you need few results and you know you are going to get them quite early in the iteration.
+# Enumerator#lazy is quite slow and should only be used when iterating over large collections
+where you need few results and you know you are going to get them quite early in the iteration.
 
 require 'benchmark/ips'
 

diff --git a/lazy.rb b/lazy.rb
@@ -1,3 +1,5 @@
+# Enumerator#lazy is quite slow and should only be used when iterating over large collections where you need few results and you know you are going to get them quite early in the iteration.
+
 require 'benchmark/ips'
 
 class Enumerator::Lazy

diff --git a/lazy.rb b/lazy.rb
@@ -22,4 +22,6 @@ def filter_map
 Calculating -------------------------------------
          map+compact     12035 i/100ms
           filter_map     10588 i/100ms
--------------------------------------------------
+-------------------------------------------------
+         map+compact   135411.8 (±0.9%) i/s -     685995 in   5.066383s
+          filter_map   114386.4 (±4.9%) i/s -     571752 in   5.010041s
diff --git a/lazy.rb b/lazy.rb
@@ -0,0 +1,25 @@
+require 'benchmark/ips'
+
+class Enumerator::Lazy
+  def filter_map
+    Lazy.new(self) do |yielder, *values|
+      result = yield *values
+      yielder << result if result
+    end
+  end
+end
+
+Benchmark.ips do |r|  
+  r.report("map+compact") do
+    (0..50).map{|a| 'lol' if a.even?}.compact.first(5)
+  end
+
+  r.report("filter_map") do
+    (0..50).lazy.filter_map{|a| 'lol' if a.even?}.first(5)
+  end
+end
+
+Calculating -------------------------------------
+         map+compact     12035 i/100ms
+          filter_map     10588 i/100ms
+-------------------------------------------------
No results found