ExceptionSafe Monad Example

gistfile1.cs

void Main()
{
  Func<int,ExceptionSafe<int>> first = x => (1000 - x).ToSafe();
	Func<int,ExceptionSafe<int>> second = x => (100/x).ToSafe();
	Func<int,ExceptionSafe<double>> third = x => (0.68 * x).ToSafe();
	
	Func<int,ExceptionSafe<double>> composed = first.Compose(second).Compose(third);
	
	900.ToSafe().ApplyFunction(composed).Dump();
}

public class ExceptionSafe<T>{
	private T _value;
	public Exception Exception{get;private set;}
	
	public ExceptionSafe(T value){
		_value=value;
	}
	
	public T Value{get{return _value;}}
	
	public ExceptionSafe(){}
	
	public void SetException(Exception ex){
		Exception = ex;
	}
	
	public ExceptionSafe<U> ApplyFunction<U>(Func<T,ExceptionSafe<U>> fun){
		var value = new ExceptionSafe<U>();
		try{
			value = fun(_value);
			if(Exception != null){
				value.SetException(Exception);
			}
		}
		catch(Exception ex){
			value.SetException(ex);
		}
		return value;
	}
}

public static class MyExtensions{
	public static Func<T,V> Compose<T,U,V>(this Func<T,U> first, Func<U,V> second){
		return (T x) => second(first(x));
	}
	public static Func<T,ExceptionSafe<V>> Compose<T,U,V>(this Func<T,ExceptionSafe<U>> first, Func<U,ExceptionSafe<V>> second){
		return (T x) => first(x).ApplyFunction(second);
	}
	public static ExceptionSafe<T> ToSafe<T>(this T value){
		return new ExceptionSafe<T>(value);
	}
}