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So you might wonder what this project is about. Well I simply saw a talk about using F# to hable processing of items in a list with "per item error handling" in a LINQ-linke query (the items were "tagged unions" or "sum type", where one instance can be of one of two strong types). I did wonder whether this would be possible in C#, so I simply tried it for fun - the result is this little project.

Example from the unit-tests:

var logger = new ExceptionLogger();
var counter = new ExecutionCounter();

var res1 = new[] { "1", "12", "123", "1234", null, "12345" }
    .WithAction<string, int>(counter.Action2)   // here we wrap each value into a function
    .WithAction<string, int>(counter.Action3)   // this will add another layer around the values
    .Skip(1)                                    // since the function execution is deferred, we will only get 5 invocations of counter.Action3
    .Try(Calculate)                             // here the value is calculated while calling the two actions defined above
    .WhenIs(logger.HandleException)             // we will execute this for each exception-item
    .ToArray();                                 // this will enumerate all items

Assert.AreEqual(5, res1.Count());           // we should have 5 return values
Assert.AreEqual(5, counter.Count);          // we have only 5 executions of the calculation
Assert.AreEqual(2, logger.List.Count());    // out list of logs contains two exceptions
Assert.AreEqual(100, (int)res1[1]);         // check for a successfull result