added a blocks example

examples/blocks.coffee

@@ -0,0 +1,57 @@
+# After wycats' http://yehudakatz.com/2010/02/07/the-building-blocks-of-ruby/
+
+# Sinatra.
+get '/hello', ->
+  'Hello World'
+
+
+# Append.
+append: (location, data) ->
+  path: new Pathname location
+  throw "Location does not exist" unless path.exists()
+
+  File.open path, 'a', (file) ->
+    file.puts YAML.dump data
+
+  data
+
+
+# Rubinius' File.open implementation.
+File.open: (path, mode, block) ->
+  io: new File path, mode
+
+  return io unless block
+
+  try
+    block io
+  finally
+    try
+      io.close() unless io.closed()
+    catch error
+      # nothing, just swallow them.
+
+
+# Write.
+write: (location, data) ->
+  path = new Pathname location
+  raise "Location does not exist" unless path.exists()
+
+  File.open path, 'w', (file) ->
+    return false if Digest.MD5.hexdigest(file.read()) is data.hash()
+    file.puts YAML.dump data
+    true
+
+
+# Rails' respond_to.
+index: ->
+  people: Person.find 'all'
+
+  respond_to (format) ->
+    format.html()
+    format.xml -> render { xml: people.xml() }
+
+
+# Synchronization.
+synchronize: (block) ->
+  lock()
+  try block() finally unlock()