org.lenskit.api

Interface Result

All Known Implementing Classes:

AbstractResult, BasicResult, FallbackResult, ItemItemResult, OrdRecRatingPredictor.FullResult, RankBlendResult, RescoredResult, UserUserResult

public interface Result

A LensKit result, consisting of a score and an ID. Individual recommenders may subclass this component to provide more detailed results.

Implementations must create well-defined equality. However, instances of different implementations are not required or expected to be able to be equal to each other. Instances are not allowed to be equal if they have different IDs.

Method Summary

Modifier and Type	Method and Description
<T extends Result> T	as(Class<T> type) Convert this result to the specified type, if possible.
long	getId() Get the ID for the result.
double	getScore() Get the score (value) associated with this result.
boolean	hasScore() Query whether the result has a score.

Method Detail

getId

long getId()

Get the ID for the result.

Returns:

The user or item ID for this result.

getScore

double getScore()

Get the score (value) associated with this result.

Returns:

The score associated with this entry (or Double.NaN if the result does not have a score).

hasScore

boolean hasScore()

Query whether the result has a score. This is equivalent to testing the return value of getScore() with Double.isNaN(double), but may make the resulting code more readable.

Returns:

true if the result has a score.

as

@Nullable
<T extends Result> T as(@Nonnull
                                   Class<T> type)

Convert this result to the specified type, if possible.

Parameters:

type - The desired result type.

T - The desired result type.

Returns:

The result as a result of type T, or null if the type cannot be cast. This may be done by casting this type, or by unwrapping wrapper result types.