Support %cat checking $LOAD_PATH directories.

lib/pry/code.rb

@@ -124,6 +124,9 @@ class Pry
         abs_path = [File.expand_path(filename, Dir.pwd),
                     File.expand_path(filename, Pry::INITIAL_PWD)
                    ].detect { |path| File.readable?(path) }
+        abs_path ||= $LOAD_PATH.map do |path|
+                       File.expand_path(File.basename(filename), path)
+                     end.detect { |path| File.readable?(path) if path }
         abs_path or raise MethodSource::SourceNotFoundError,
                           "Cannot open #{filename.inspect} for reading."
       end

spec/code_spec.rb

@@ -46,6 +46,11 @@ describe Pry::Code do
         Pry::Code.from_file(File.basename(__FILE__)).code_type.should == :ruby
       end
     end
+    
+    should 'find files that are relative to a directory in the $LOAD_PATH' do
+      $LOAD_PATH << 'spec'
+      Pry::Code.from_file(File.basename(__FILE__)).code_type.should == :ruby
+    end
   end
 
   describe '.from_method' do