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2 files changed, 97 insertions, 0 deletions

diff --git a/lib/method_source.rb b/lib/method_source.rb
new file mode 100644
index 0000000..bdb00ed
--- /dev/null
+++ b/lib/method_source.rb
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+# (C) John Mair (banisterfiend) 2010
+# MIT License
+
+direc = File.dirname(__FILE__)
+
+require 'stringio'
+require "#{direc}/method_source/version"
+
+module MethodSource
+
+  # Helper method used to find end of method body
+  # @param [String] code The string of Ruby code to check for
+  # correctness
+  # @return [Boolean] 
+  def self.valid_expression?(code)
+    suppress_stderr do
+      RubyVM::InstructionSequence.new(code)
+    end
+  rescue Exception
+    false
+  else
+    true
+  end
+
+  # Helper method used to suppress stderr output by the
+  # `RubyVM::InstructionSequence` method
+  # @yield The block where stderr is suppressed
+  def self.suppress_stderr
+    real_stderr, $stderr = $stderr, StringIO.new
+    yield
+  ensure
+    $stderr = real_stderr
+  end
+
+  # Helper method responsible for opening source file and advancing to
+  # the correct linenumber. Defined here to avoid polluting `Method`
+  # class.
+  # @param [Array] source_location The array returned by Method#source_location
+  # @return [File] The opened source file
+  def self.source_helper(source_location)
+    return nil if !source_location.is_a?(Array)
+    
+    file_name, line = source_location
+    file = File.open(file_name)
+    (line - 1).times { file.readline }
+    file
+  end
+  
+  # This module is to be included by `Method` and `UnboundMethod` and
+  # provides the `#source` functionality
+  module MethodExtensions
+    
+    # Return the sourcecode for the method as a string
+    # (This functionality is only supported in Ruby 1.9 and above)
+    # @return [String] The method sourcecode as a string
+    # @example
+    #  Set.instance_method(:clear).source.display
+    #  =>
+    #     def clear
+    #       @hash.clear
+    #       self
+    #     end
+    def source
+      file = nil
+      
+      if respond_to?(:source_location)
+        file = MethodSource.source_helper(source_location)
+        
+        raise "Cannot locate source for this method: #{name}" if !file
+      else
+        raise "Method#source not supported by this Ruby version (#{RUBY_VERSION})"
+      end
+
+      code = ""
+      loop do
+        val = file.readline
+        code += val
+        
+        return code if MethodSource.valid_expression?(code)
+      end
+      
+    ensure
+      file.close if file
+    end
+  end
+end
+
+class Method
+  include MethodSource::MethodExtensions
+end
+
+class UnboundMethod
+  include MethodSource::MethodExtensions
+end
diff --git a/lib/method_source/version.rb b/lib/method_source/version.rb
new file mode 100644
index 0000000..30c0683
--- /dev/null
+++ b/lib/method_source/version.rb
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+module MethodSource
+  VERSION = "0.1.0"
+end