public void EitherExistsLeftFalseWhenRight()
{
bool expected = false;
Either <string, int> either = 10;
bool result =
EitherModule.ExistsLeft(
right => right == "Hello"
, either);
Assert.AreEqual(expected, result);
}
public void EitherExistsLeftTrueWhenLeft()
{
bool expected = true;
Either <string, int> either = "Hello";
bool result =
EitherModule.ExistsLeft(
right => right == "Hello"
, either);
Assert.AreEqual(expected, result);
}
/// <summary>
/// Returns true when <paramref name="either"/> <see cref="Either{TLeft, TRight}.IsLeft"/> and given <paramref name="predicate"/> function applied to <paramref name="either"/> return true.
/// Otherwise, returns false.
/// </summary>
/// <typeparam name="TLeft">The type of the left value.</typeparam>
/// <typeparam name="TRight">The type of the right value.</typeparam>
/// <param name="predicate">A function that evaluates whether the left value contained in the option is valid or not.</param>
/// <param name="either">the input either.</param>
/// <returns>
/// Returns true if the given predicate functions return true when applied to either value.
/// </returns>
public static bool ExistsLeft <TLeft, TRight>(this Either <TLeft, TRight> either, Func <TLeft, bool> predicate)
=> EitherModule.ExistsLeft(predicate, either);