c# exit generic ForEach that use lambda

Question

Does anyone know if it is possible to exit a generic ForEach that uses lambda? e.g.

someList.ForEach(sl =>
  {
    if (sl.ToString() == "foo")
        break;

    // continue processing sl here
    // some processing code
  }
);

This code itself won't compile. I know I could use a regular foreach but for consistency I want to use lambda.

Many thanks.

Answer 1

Sure. But first, note that I recommend against this; I say that a sequence operator should not have a side effect, and a statement should have a side effect. If you're doing something in that ForEach lambda, then make it a statement in the body of a foreach loop rather than making it look like a sequence operator.

That said, here's what you do. First, you write yourself a ForEach that works on arbitrary sequences, not just lists:

public static void ForEach<T>(this IEnumerable<T> sequence, Action<T> action)
{
    foreach(var item in sequence) action(item);
}

And now you write your break like this:

someList
    .TakeWhile(x=>x.ToString() != "foo")
    .ForEach(sl=>
    {/*your action here*/});