anchor.diff:  %% 3) ****when an erlang file does not compile, the detector should still return the result before trim_clones.
   
   
  --define(DEFAULT_MIN_CLONE_LEN, 10).  %% in the number of tokens.
  +-define(DEFAULT_MIN_CLONE_LEN, 20).  %% minimal number of tokens.
   -define(DEFAULT_MIN_CLONE_MEMBER, 2).
  -
  -test() ->
  -    duplicated_code(["refac_batch_rename_mod.erl", "refac_callgraph.erl", 
  -		      "refac_duplicated_code.erl",
  -                    %%  "refac_epp_dodger.erl", 
  -		      "refac_expr_search.erl", "refac_util.erl",
  -		      "refac_epp.erl",
  - 		     "refac_fold_expression.erl", "refac_gen.erl",
  - 		     "refac_io.erl", "refac_module_graph.erl",
  - 		     "refac_move_fun.erl", "refac_new_fun.erl",
  -%% 		     "refac_parse.erl",
  - 		     "refac_prettypr.erl", "refac_recomment.erl",
  - 		     "refac_rename_fun.erl", "refac_rename_mod.erl",
  - 		     "refac_rename_var.erl", 
  -		     "refac_scan.erl", 
  - 		     "refac_syntax.erl",
  -                    "refac_syntax_lib.erl", 
  -		    "wrangler.erl", "wrangler_distel.erl", "wrangler_options.erl"], "30", "2").
  -
  -
  -test1()->
  -   duplicated_code(["refac_duplicated_code.erl"], "30","2").
  -
  -test2()->
  -    Files = refac_util:expand_files(["c:/cygwin/home/hl/CodeBase/ic-0.1.2"], ".erl"),
  -    io:format("Files:\n~p\n", [Files]),
  -    duplicated_code(Files, "30","2").
   
   %% ==================================================================================
   %% @doc Find duplicated code in a Erlang source files.
  
positive.code: 	{string, _L3, _V3} -> 'S';  
  	{float, _, _} ->'F';        
  	{char, _, _} ->'C' ;        
  	{A, _} -> case lists:keysearch(A, 1, alphabet_1()) of 
  		      {value, {A, Value}} -> Value;
  		      _  -> erlang:error(io:format("Unhandled token:\n~p\n", [T]))
  		  end
  
negative.code: 
  -module(refac_duplicated_code).
  
  -export([duplicated_code/3]).
  
  -export([duplicated_code_1/3,suffix_tree/2, remove_var_literals/1]).
  
  %% TODO:  
  %% 1) does recusive function calls affect the result?
  