public void EitherIterateLeftWhenLeft()
{
string expected = "Hello World";
string result = "World";
Either <string, int> either = "Hello ";
EitherModule.IterateLeft(
left => result = string.Concat(left, result)
, either);
Assert.AreEqual(expected, result);
}
/// <summary>Applies the given function to <see cref="Either{TLeft, TRight}"/> value when <see cref="Either{TLeft, TRight}.IsLeft"/>.</summary>
/// <typeparam name="TLeft">The type of the left value.</typeparam>
/// <typeparam name="TRight">The type of the right value.</typeparam>
/// <param name="action">The action to apply to left value of input <paramref name="either"/>.</param>
/// <param name="either">the input either.</param>
public static void IterateLeft <TLeft, TRight>(this Either <TLeft, TRight> either, Action <TLeft> action)
=> EitherModule.IterateLeft(action, either);