1 files changed, 55 insertions, 0 deletions
diff --git a/ext/ripper/lib/ripper/filter.rb b/ext/ripper/lib/ripper/filter.rb
new file mode 100644
index 0000000000..399c4c64bc
--- /dev/null
+++ b/ext/ripper/lib/ripper/filter.rb
@@ -0,0 +1,55 @@
+#
+# ripper/filter.rb
+#
+# Copyright (C) 2004 Minero Aoki
+#
+# This program is free software.
+# You can distribute and/or modify this program under the Ruby License.
+# For details of Ruby License, see ruby/COPYING.
+#
+
+require 'ripper'
+
+class Ripper
+
+  class Filter
+
+    def initialize(src, filename = '-', lineno = 1)
+      @__parser = Tokenizer.new(src, filename, lineno)
+      @__line = nil
+      @__col = nil
+    end
+
+    def filename
+      @__parser.filename
+    end
+
+    def lineno
+      @__line
+    end
+
+    def column
+      @__col
+    end
+
+    def parse(init)
+      data = init
+      @__parser.parse.each do |pos, event, tok|
+        @__line, @__col = *pos
+        data = if respond_to?(event, true)
+               then __send__(event, tok, data)
+               else on_default(event, tok, data)
+               end
+      end
+      data
+    end
+
+    private
+
+    def on_default(event, tok, data)
+      data
+    end
+
+  end
+
+end