lib/ripper-plus/scope_stack.rb in ripper-plus-1.1.0.pre2 vs lib/ripper-plus/scope_stack.rb in ripper-plus-1.2.0

@@ -23,10 +23,13 @@
         end
       end.join(' ')
       "< #{middle} >"
     end
 
-    def add_variable(var)
+    def add_variable(var, allow_duplicates=true)
+      if !allow_duplicates && @stack.last.include?(var)
+        raise DuplicateArgumentError.new("duplicated argument name (#{var})")
+      end
       @stack.last << var
     end
   
     # An open scope permits reference to local variables in enclosing scopes.
     def with_open_scope
\ No newline at end of file