在c#函数式编程中正确选择哪一个？

Question

我正在尝试使用c#学习函数式编程

我正在使用https://github.com/louthy/language-ext

如何才能在不使用.Match的情况下从这两个值中提取正确的值

如果没有临时变量，如何返回UpdateLocations的结果？

任一

public static Either<Exception, string[]> ExtractStringArray(IQueryCollection query, string filter)
        {
            try
            {
                return query.First(x => x.Key.ToLower() == filter).Value.ToString().Split(',').ToArray();
            }
            catch (Exception ex)
            {
                return ex;
            }
        }

异常情况

 static void HandleException(Exception ex) => Console.WriteLine(ex);

我正在使用下面的代码提取输出，有没有其他选择？

 private static string[] UpdateLocations(IQueryCollection query)
        {
            // creating a temporary value here
            string[] locations = new string[] { };

            ExtractStringArray(query, "location")
                .Match(
                    Left: ex => HandleException(ex),
                    Right: loc => locations = loc);

            return locations;
        }

更新变量

   var query = request.Query;
   result.Locations = UpdateLocations(query);

Answer 1

// simplify ExtractStringArray using Try
static Either<Exception, string[]> ExtractStringArray(IQueryCollection query, string filter) =>
    Try(() => query.First(x => x.Key.ToLower() == filter).Value.ToString().Split(',').ToArray())
      .ToEither();

static void HandleException(Exception ex) => Console.WriteLine(ex);

var query = request.Query;
// now get result or exception (Either<...>)
var resultOrException = ExtractStringArray(query, "location");

// now execute side-effect if exception
resultOrException.IfLeft(HandleException); // side-effect (log error)

// now use result and supply default value in case of exception
result.Locations = resultOrException.IfLeft(new string[]{ });