Improve performance

lib/fasterer/file_traverser.rb

@@ -21,6 +21,7 @@ def initialize(path)
       @parse_error_paths = []
       @config = Config.new
       @offenses_total_count = 0
+      @explanation = {}
     end
 
     def traverse
@@ -84,9 +85,7 @@ def output(analyzer)
       offenses_grouped_by_type(analyzer).each do |error_group_name, error_occurences|
         error_occurences.map(&:line_number).each do |line|
           file_and_line = "#{analyzer.file_path}:#{line}"
-          message = Fasterer::Explanation.new(error_group_name).call
-
-          print "#{file_and_line.colorize(:red)} #{message}\n"
+          print "#{file_and_line.colorize(:red)} #{explanation(error_group_name)}\n"
         end
       end
 
@@ -129,6 +128,10 @@ def ignored_files
     def nil_config_file
       config.nil_file
     end
+
+    def explanation(offense_name)
+      @explanations[offense_name] ||= Fasterer::Explanation.new(offense_name).call
+    end
   end
 
   ErrorData = Struct.new(:file_path, :error_class, :error_message) do