/// <summary>
/// Maps all of the examples in an example space by the given selector function.
/// </summary>
/// <typeparam name="T">The type of the target example space's values.</typeparam>
/// <typeparam name="TResult">The new type of an example's value</typeparam>
/// <param name="exampleSpace">The example space to operate on.</param>
/// <param name="selector">A function to apply to each example in the example space.</param>
/// <returns>A new example space with the mapping function applied.</returns>
public static IExampleSpace <TResult> MapExamples <T, TResult>(
this IExampleSpace <T> exampleSpace,
Func <IExample <T>, IExample <TResult> > f)
{
return(ExampleSpaceFactory.Create(
f(exampleSpace.Current),
exampleSpace.Subspace.Select(es => MapExamples(es, f))));
}
/// <summary>
/// Filters the examples in an example space by the given predicate.
/// </summary>
/// <typeparam name="T">The type of the target example space's values.</typeparam>
/// <param name="exampleSpace">The example space to operate on.</param>
/// <param name="pred">The predicate used to test each value in the example space.</param>
/// <returns>A new example space, containing only the examples whose values passed the predicate.</returns>
public static IExampleSpace <T>?Filter <T>(
this IExampleSpace <T> exampleSpace,
Func <T, bool> pred)
{
if (pred(exampleSpace.Current.Value) == false)
{
return(null);
}
return(ExampleSpaceFactory.Create(
exampleSpace.Current,
exampleSpace.Subspace
.Select(es => es.Filter(pred))
.Where(es => es != null)
.Cast <IExampleSpace <T> >()));
}
public static IExampleSpace <T> Cast <T>(this IExampleSpace exampleSpace)
{
T newValue;
try
{
newValue = (T)exampleSpace.Current.Value;
}
catch
{
newValue = (T)Convert.ChangeType(exampleSpace.Current.Value, typeof(T));
}
var example = new Example <T>(exampleSpace.Current.Id, newValue, exampleSpace.Current.Distance);
var subspace = exampleSpace.Subspace.Select(child => Cast <T>(child));
return(ExampleSpaceFactory.Create(example, subspace));
}
