public void TestEmptySet()
{
var expected = 1.LiftList();
var zipper = ConsListZipper <int> .ToZipper(ConsList.Nil <int>());
var result = zipper.Set(1).ToList();
Assert.AreEqual(expected, result);
}
public static StateEither <TState, TLeft, IEnumerable <TRight> > Sequence <TState, TLeft, TRight>(this IEnumerable <StateEither <TState, TLeft, TRight> > stateTs)
{
return(new StateEither <TState, TLeft, IEnumerable <TRight> >(new State <TState, IEither <TLeft, IEnumerable <TRight> > >(s =>
{
var retval = ConsList.Nil <TRight>().AsRight <TLeft, IConsList <TRight> >();
foreach (var state in stateTs)
{
var res = state.Out.Run(s);
s = res.Item1;
retval =
from xs in retval
from x in res.Item2
select x.Cons(xs);
}
return Tuple.Create(s, retval.Select(xs => xs.AsEnumerable().Reverse()));
})));
}
public void TestApplicative(string firstName, string lastName, int age, int[] expectedErrors)
{
var m = EnumerableMonoid <Failure> .Only;
Func <string, string, int, Person> makePerson = Person.MakePerson;
var personOrError =
ValidateStringNotNull(firstName).SelectMany(ValidateNameLength)
.Select(makePerson.Curry())
.Apply(ValidateStringNotNull(lastName).SelectMany(ValidateNameLength), m)
.Apply(ValidateAgeInRange(age), m);
var errorCodes = personOrError.Match(
success: p => ConsList.Nil <int>(),
failure: errors => errors.Select(error => error.ErrorCode).ToConsList());
var expectedErrorList = expectedErrors.ToConsList();
Assert.IsTrue(expectedErrors.ToConsList().Equals(errorCodes));
}
public void TestAsEnumerable(IEnumerable <int> expected, int fake)
{
var actual = 1.Cons(2.Cons(3.Cons(ConsList.Nil <int>()))).AsEnumerable();
Assert.AreEqual(expected, actual);
}
private static IConsList <T> MkList <T>(IEnumerable <T> ts)
{
return(ts.Reverse().Aggregate(ConsList.Nil <T>(), (lst, t) => t.Cons(lst)));
}
/// <summary>
/// Alters the zipper to point at the last element in the source list
/// </summary>
/// <returns>A new zipper with the pointer set to the first element of the source list</returns>
public ConsListZipper <T> Last()
{
return(new ConsListZipper <T>(_after.FoldL(_before, (befores, a) => a.Cons(befores)), ConsList.Nil <T>()).Prev());
}
/// <summary>
/// Alters the zipper to point at the first element in the source list
/// </summary>
/// <returns>A new zipper with the pointer set to the first element of the source list</returns>
public ConsListZipper <T> First()
{
return(new ConsListZipper <T>(ConsList.Nil <T>(), _before.FoldL(_after, (afters, b) => b.Cons(afters))));
}
/// <summary>
/// Helper that constructs a zipper from a cons list
/// </summary>
/// <param name="xs">The list you wish to create a zipper for</param>
/// <returns>A new zipper</returns>
public static ConsListZipper <T> ToZipper(IConsList <T> xs)
{
return(new ConsListZipper <T>(ConsList.Nil <T>(), xs));
}
public static Task <IEnumerable <T> > Sequence <T>(this IEnumerable <Task <T> > taskTs)
{
var initial = Task.FromResult(ConsList.Nil <T>());
return(taskTs.Reverse().Aggregate(initial, (current, task) => current.SelectMany(ts => task.Select(t => t.Cons(ts)))).Select(tasks => tasks.AsEnumerable()));
}
/// <summary>
/// Sequence takes a list of computations and builds from them a computation which will
/// run each in turn and produce a list of the results.
///
/// Note that due to C#s lack of higher kinded types, this must be specified for every type of computation
/// This is the sequence for IMaybe computations
/// </summary>
/// <typeparam name="T">Type of value yielded by each computation</typeparam>
/// <param name="maybeTs">The list of computations</param>
/// <returns>A computation thqt yields a sequence of values of type 'T</returns>
public static IMaybe <IEnumerable <T> > Sequence <T>(this IEnumerable <IMaybe <T> > maybeTs)
{
var initial = ConsList.Nil <T>().ToMaybe();
return(maybeTs.Reverse().Aggregate(initial, (current, maybe) => current.SelectMany(ts => maybe.Select(t => t.Cons(ts)))).Select(xs => xs.AsEnumerable()));
}
public static StateIo <TState, IEnumerable <TValue> > Sequence <TState, TValue>(this IEnumerable <StateIo <TState, TValue> > stateTs)
{
var initial = ConsList.Nil <TValue>().ToStateIo <TState, IConsList <TValue> >();
return(stateTs.Aggregate(initial, (current, anIoState) => current.SelectMany(ts => anIoState.Select(t => t.Cons(ts)))).Select(ioStates => ioStates.AsEnumerable().Reverse()));
}
public static IEither <TLeft, IEnumerable <TRight> > Sequence <TLeft, TRight>(this IEnumerable <IEither <TLeft, TRight> > xs)
{
var initial = ConsList.Nil <TRight>().AsRight <TLeft, IConsList <TRight> >();
return(xs.Aggregate(initial, (current, anEither) => current.SelectMany(ts => anEither.Select(t => t.Cons(ts)))).Select(eithers => eithers.AsEnumerable().Reverse()));
}
/// <summary>
/// Sequence takes a list of computations and builds from them a computation which will
/// run each in turn and produce a list of the results.
///
/// Note that due to C#s lack of higher kinded types, this must be specified for every type of computation
/// This is the sequence for State computations
/// </summary>
/// <typeparam name="TState">Type of associated state</typeparam>
/// <typeparam name="T">Type of value yielded by each computation</typeparam>
/// <param name="states">The list of computations</param>
/// <returns>A computation thqt yields a sequence of values of type 'T</returns>
public static State <TState, IEnumerable <T> > Sequence <TState, T>(this IEnumerable <State <TState, T> > states)
{
var initial = ConsList.Nil <T>().Insert <TState, IConsList <T> >();
return(states.Aggregate(initial, (current, s) => current.SelectMany(ts => s.Select(t => t.Cons(ts)))).Select(x => x.AsEnumerable().Reverse()));
}