3 files changed, 93 insertions, 13 deletions
diff --git a/lib/method_source.rb b/lib/method_source.rb
index d6a6e29..43651b9 100644
--- a/lib/method_source.rb
+++ b/lib/method_source.rb
@@ -4,19 +4,41 @@
 direc = File.dirname(__FILE__)
 
 require "#{direc}/method_source/version"
-
-if RUBY_VERSION =~ /1.9/
-  require 'ripper'
-end
+require "#{direc}/method_source/source_location"
 
 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)
-    !!Ripper::SexpBuilder.new(code).parse
+  if RUBY_VERSION =~ /1.9/
+    require 'ripper'
+
+    # Determine if a string of code is a valid Ruby expression.
+    # Ruby 1.9 uses Ripper, Ruby 1.8 uses RubyParser.
+    # @param [String] code The code to validate.
+    # @return [Boolean] Whether or not the code is a valid Ruby expression.
+    # @example
+    #   valid_expression?("class Hello") #=> false
+    #   valid_expression?("class Hello; end") #=> true
+    def self.valid_expression?(code)
+      !!Ripper::SexpBuilder.new(code).parse
+    end
+
+  else
+    require 'ruby_parser'
+
+    # Determine if a string of code is a valid Ruby expression.
+    # Ruby 1.9 uses Ripper, Ruby 1.8 uses RubyParser.
+    # @param [String] code The code to validate.
+    # @return [Boolean] Whether or not the code is a valid Ruby expression.
+    # @example
+    #   valid_expression?("class Hello") #=> false
+    #   valid_expression?("class Hello; end") #=> true
+    def self.valid_expression?(code)
+      RubyParser.new.parse(code)
+    rescue Racc::ParseError, SyntaxError
+      false
+    else
+      true
+    end
   end
 
   # Helper method responsible for extracting method body.
@@ -86,7 +108,7 @@ module MethodSource
         
         raise "Cannot locate source for this method: #{name}" if !source
       else
-        raise "Method#source not supported by this Ruby version (#{RUBY_VERSION})"
+        raise "#{self.class}#source not supported by this Ruby version (#{RUBY_VERSION})"
       end
       
       source
@@ -105,7 +127,7 @@ module MethodSource
         
         raise "Cannot locate source for this method: #{name}" if !comment
       else
-        raise "Method#comment not supported by this Ruby version (#{RUBY_VERSION})"
+        raise "#{self.class}#comment not supported by this Ruby version (#{RUBY_VERSION})"
       end
 
       comment
@@ -114,10 +136,12 @@ module MethodSource
 end
 
 class Method
+  include MethodSource::SourceLocation::MethodExtensions
   include MethodSource::MethodExtensions
 end
 
 class UnboundMethod
+  include MethodSource::SourceLocation::UnboundMethodExtensions
   include MethodSource::MethodExtensions
 end
 
diff --git a/lib/method_source/source_location.rb b/lib/method_source/source_location.rb
new file mode 100644
index 0000000..1878b18
--- /dev/null
+++ b/lib/method_source/source_location.rb
@@ -0,0 +1,56 @@
+module MethodSource
+  module SourceLocation
+    module MethodExtensions
+      def trace_func(event, file, line, id, binding, classname)
+        return unless event == 'call'
+        set_trace_func nil 
+        
+        @file, @line = file, line
+        raise :found
+      end
+      
+      # Return the source location of a method for Ruby 1.8.
+      # @return [Array] A two element array. First element is the
+      #   file, second element is the line in the file where the
+      #   method definition is found.
+      def source_location
+        if @file.nil?
+          args =[*(1..(arity<-1 ? -arity-1 : arity ))]
+          
+          set_trace_func method(:trace_func).to_proc
+          call *args rescue nil
+          set_trace_func nil 
+          @file = File.expand_path(@file) if @file && File.exist?(File.expand_path(@file))
+        end
+        return [@file, @line] if File.exist?(@file.to_s)
+      end
+    end
+
+    module UnboundMethodExtensions
+
+      # Return the source location of an instance method for Ruby 1.8.
+      # @return [Array] A two element array. First element is the
+      #   file, second element is the line in the file where the
+      #   method definition is found.
+      def source_location
+        klass = case owner
+                when Class
+                  owner
+                when Module
+                  Class.new.tap { |v| v.send(:include, owner) }
+                end
+
+        begin
+          klass.allocate.method(name).source_location
+        rescue TypeError
+
+          # Assume we are dealing with a Singleton Class:
+          # 1. Get the instance object
+          # 2. Forward the source_location lookup to the instance
+          instance ||= ObjectSpace.each_object(owner).first
+          instance.method(name).source_location
+        end
+      end
+    end
+  end
+end
diff --git a/lib/method_source/version.rb b/lib/method_source/version.rb
index 2ac241c..6a830a9 100644
--- a/lib/method_source/version.rb
+++ b/lib/method_source/version.rb
@@ -1,3 +1,3 @@
 module MethodSource
-  VERSION = "0.2.0"
+  VERSION = "0.3.0"
 end