///<summary>
///Returns an action which
///</summary>
///<param name="action"></param>
///<param name="finalizer"></param>
///<typeparam name="T"></typeparam>
///<returns></returns>
public static ActionCPS <T> WithFinally <T>(this ActionCPS <T> action, Action finalizer)
{
return(cont => {
action(cont);
finalizer();
});
}
///<summary>
///Returns an action which attempts <paramref name="action"/> first, calls
///<paramref name="rescue"/> in case of failure.
///</summary>
///<param name="action">The action to try.</param>
///<param name="rescue">The action to call if <paramref name="action"/> fails.</param>
public static ActionCPS <T> WithRescue <T>(this ActionCPS <T> action,
Func <Exception, ActionCPS <T> > rescue)
{
return(cont => action.RunR().Match(
t => cont.Ok(t),
e => rescue(e)(cont)));
}
/// <summary>
/// Do <paramref name="first"/>; if it succeeds then do <paramref name="second"/>.
/// </summary>
/// <typeparam name="T1">The type of the <paramref name="first"/> action.</typeparam>
/// <typeparam name="T2">The type of the <paramref name="second"/> action.</typeparam>
/// <param name="first">The first action.</param>
/// <param name="second">The second action.</param>
/// <returns>The combined action</returns>
public static ActionCPS <T2> Then <T1, T2>(this ActionCPS <T1> first,
Func <T1, ActionCPS <T2> > second)
{
return(cont => first(new Cont <T1>(
t1 => second(t1)(cont),
e => cont.Fail(e))));
}
///<summary>
///Runs the action with the trivial continuation. Returns
///<see cref="Result{T}.Failure"/> in the case action fails.
///</summary>
///<param name="action"></param>
///<typeparam name="T"></typeparam>
public static Result <T> RunR <T>(this ActionCPS <T> action)
{
Result <T> result = null;
try {
action(new Cont <T>(
t => { result = Result.Success(t); },
e => { result = Result.Failure <T>(e); }));
return(result);
}
catch (Exception e) {
return(Result.Failure <T>(e));
}
}
///<summary>
///Runs the action with the trivial continuation. Throws an
///<see cref="ActionFailureException"/> in the case action fails.
///</summary>
///<param name="action"></param>
///<typeparam name="T"></typeparam>
public static T Run <T>(this ActionCPS <T> action)
{
return(action.RunR().Match(
x => x,
e => { throw new ActionFailureException(e); }));
}
///<summary>
///Returns an action which attempts <paramref name="action"/> first and does
///<paramref name="ifFirstActionFails"/> if it fails.
///</summary>
///<param name="action">The action to try.</param>
///<param name="ifFirstActionFails">The action to do if <paramref name="action"/>
///fails.</param>
///<typeparam name="T"></typeparam>
///<returns></returns>
public static ActionCPS <T> OrElse <T>(this ActionCPS <T> action,
ActionCPS <T> ifFirstActionFails)
{
return(action.WithRescue(e => ifFirstActionFails));
}
///<summary>
///Returns an action which attempts <paramref name="action"/> first, returns <paramref name="defaultResult"/> if
/// it fails.
///</summary>
///<param name="action">The action to try.</param>
///<param name="defaultResult">The result if <paramref name="action"/> fails.</param>
public static ActionCPS <T> WithDefault <T>(this ActionCPS <T> action, T defaultResult)
{
return(action.WithRescue(e => Return(defaultResult)));
}
