add fiber iterator: each block is wrapped in a fiber + auto-advance

README.md

@@ -45,6 +45,27 @@ EM.synchrony do
 end
 ```
 
+Or, you can use FiberIterator to hide the async nature of em-http:
+
+```ruby
+require "em-synchrony"
+require "em-synchrony/em-http"
+
+EM.synchrony do
+    concurrency = 2
+    urls = ['http://url.1.com', 'http://url2.com']
+    results = []
+
+    EM::Synchrony::FiberIterator.new(urls, concurrency).each do |url|
+        resp = EventMachine::HttpRequest.new(url).get
+    results.push resp.response
+    end
+
+    p results # all completed requests
+    EventMachine.stop
+end
+```
+
 ## Fiber-aware ConnectionPool shared by a fiber:
 Allows you to create a pool of resources which are then shared by one or more fibers. A good example is a collection of long-lived database connections. The pool will automatically block and wake up the fibers as the connections become available.
 

lib/em-synchrony/fiber_iterator.rb

@@ -0,0 +1,18 @@
+module EventMachine
+  module Synchrony
+
+    class FiberIterator < EM::Synchrony::Iterator
+
+      # execute each iterator block within its own fiber
+      # and auto-advance the iterator after each call
+      def each(foreach=nil, after=nil, &blk)
+        fe = Proc.new do |obj, iter|
+          Fiber.new { (foreach || blk).call(obj); iter.next }.resume
+        end
+
+        super(fe, after)
+      end
+
+    end
+  end
+end

spec/fiber_iterator_spec.rb

@@ -0,0 +1,39 @@
+require "spec/helper/all"
+require "em-synchrony/fiber_iterator"
+
+describe EventMachine::Synchrony::FiberIterator do
+
+  it "should wait until the iterator is done and wrap internal block within a fiber" do
+    EM.synchrony do
+
+      results = []
+      i = EM::Synchrony::FiberIterator.new(1..5, 2).each do |num|
+        EM::Synchrony.sleep(0.1)
+        results.push num
+      end
+
+      results.should == (1..5).to_a
+      results.size.should == 5
+      EventMachine.stop
+    end
+  end
+
+  #
+  # it "should sum values within the iterator" do
+  #   EM.synchrony do
+  #     data = (1..5).to_a
+  #     res = EM::Synchrony::FiberIterator.new(data, 2).inject(0) do |total, num, iter|
+  #       EM::Synchrony.sleep(0.1)
+  #
+  #       p [:sync, total, num]
+  #       iter.return(total += num)
+  #     end
+  #
+  #     res.should == data.inject(:+)
+  #     EventMachine.stop
+  #   end
+  # end
+
+
+
+end