public void OptionApplyWhenSomeFunctionSomeValue()
{
Option <Func <int, bool> > optionFunction = _isEven;
Option <int> optionValue = 36;
Option <bool> optionResult =
OptionModule.Apply(optionFunction, optionValue);
bool result = optionResult.Match(value => value, () => false);
Assert.IsTrue(optionResult.IsSome && result);
}
public void OptionApplyWhenNoneFunctionNoneValue()
{
Option <Func <int, bool> > optionFunction = Option <Func <int, bool> > .None();
Option <int> optionValue = Option <int> .None();
Option <bool> optionResult =
OptionModule.Apply(optionFunction, optionValue);
bool result = optionResult.Match(value => value, () => false);
Assert.IsTrue(optionResult.IsNone);
}
/// <summary>
/// Creates a new <see cref="Option{T}"/> whose value is the result of applying the given <paramref name="applying"/> function
/// to <see cref="Option{T}.Some(T)"/> value when both <paramref name="applying"/> and <paramref name="option"/> are <see cref="Option{T}.IsSome"/>.
/// Otherwise returns an <see cref="Option{T}.None"/>.
/// </summary>
/// <typeparam name="T">The type of the option value.</typeparam>
/// <typeparam name="TResult">The type of the value returned by <paramref name="applying"/> function.</typeparam>
/// <param name="applying">The option function to transform option value from the input option.</param>
/// <param name="option">The input option.</param>
/// <returns>
/// Returns a new <see cref="Option{T}"/> whose value is the result of applying the given <paramref name="applying"/> function
/// to <see cref="Option{T}.Some(T)"/> value when both <paramref name="applying"/> and <paramref name="option"/> are <see cref="Option{T}.IsSome"/>.
/// Otherwise returns an <see cref="Option{T}.None"/>.
/// </returns>
public static Option <TResult> Apply <T, TResult>(this Option <T> option, Option <Func <T, TResult> > applying)
=> OptionModule.Apply(applying, option);