private static void LearnFromNewExample()

in dsl-samples/tutorial/part1c-complete/ProseTutorial/Program.cs [78:128]
45 lines of code
9 McCabe index (conditional complexity)

        private static void LearnFromNewExample()
        {
            Console.Out.Write("Provide a new input-output example (e.g., \"(Sumit Gulwani)\",\"Gulwani\"): ");
            try
            {
                string input = Console.ReadLine();
                if (input != null)
                {
                    int startFirstExample = input.IndexOf("\"", StringComparison.Ordinal) + 1;
                    int endFirstExample = input.IndexOf("\"", startFirstExample + 1, StringComparison.Ordinal) + 1;
                    int startSecondExample = input.IndexOf("\"", endFirstExample + 1, StringComparison.Ordinal) + 1;
                    int endSecondExample = input.IndexOf("\"", startSecondExample + 1, StringComparison.Ordinal) + 1;

                    if (startFirstExample >= endFirstExample || startSecondExample >= endSecondExample)
                        throw new Exception(
                            "Invalid example format. Please try again. input and out should be between quotes");

                    string inputExample = input.Substring(startFirstExample, endFirstExample - startFirstExample - 1);
                    string outputExample =
                        input.Substring(startSecondExample, endSecondExample - startSecondExample - 1);

                    State inputState = State.CreateForExecution(Grammar.InputSymbol, inputExample);
                    Examples.Add(inputState, outputExample);
                }
            }
            catch (Exception)
            {
                throw new Exception("Invalid example format. Please try again. input and out should be between quotes");
            }

            var spec = new ExampleSpec(Examples);
            Console.Out.WriteLine("Learning a program for examples:");
            foreach (KeyValuePair<State, object> example in Examples)
                Console.WriteLine("\"{0}\" -> \"{1}\"", example.Key.Bindings.First().Value, example.Value);

            var scoreFeature = new RankingScore(Grammar);
            ProgramSet topPrograms = _prose.LearnGrammarTopK(spec, scoreFeature, 4, null);
            if (topPrograms.IsEmpty) throw new Exception("No program was found for this specification.");

            _topProgram = topPrograms.RealizedPrograms.First();
            Console.Out.WriteLine("Top 4 learned programs:");
            var counter = 1;
            foreach (ProgramNode program in topPrograms.RealizedPrograms)
            {
                if (counter > 4) break;
                Console.Out.WriteLine("==========================");
                Console.Out.WriteLine("Program {0}: ", counter);
                Console.Out.WriteLine(program.PrintAST(ASTSerializationFormat.HumanReadable));
                counter++;
            }
        }