readme: keep correct order in p_map example

0x1eef · Jun 24, 2022 · 9d5101c · 9d5101c
1 parent cf43614
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diff --git a/README.md b/README.md
@@ -64,16 +64,21 @@ require "xchan"
 
 def p_map(enum)
   ch = xchan
-  enum.map { |e| Process.fork { ch.send yield(e) } }
+  enum.map
+      .with_index { |e, i| fork { sleep(e); ch.send yield([e * 2, i]) } }
       .each { Process.wait(_1) }
   enum.map  { ch.recv }
+      .sort { _1.pop  }
+      .map  { _1[0]   }
 end
 
-Kernel.p p_map([1,2,3]) { _1 * 2 }
+t = Time.now
+print p_map([3, 2, 1]) { _1 * 2 }, "\n"
+print "Duration: #{Time.now - t}", "\n"
 
-##
 # == Output
-# [2, 4, 6]
+# [6, 4, 2]
+# Duration: 3.00XXX
 ```
 
 **Send a Ruby object to a child process**

diff --git a/readme_examples/2_parallel_map.rb b/readme_examples/2_parallel_map.rb
@@ -2,9 +2,18 @@
 
 def p_map(enum)
   ch = xchan
-  enum.map { |e| Process.fork { ch.send yield(e) } }
+  enum.map
+      .with_index { |e, i| fork { sleep(e); ch.send yield([e * 2, i]) } }
       .each { Process.wait(_1) }
   enum.map  { ch.recv }
+      .sort { _1.pop  }
+      .map  { _1[0]   }
 end
 
-p p_map([1,2,3]) { _1 * 2 }
+t = Time.now
+print p_map([3, 2, 1]) { _1 * 2 }, "\n"
+print "Duration: #{Time.now - t}", "\n"
+
+# == Output
+# [6, 4, 2]
+# Duration: 3.00XXX