Let nullable ScoredValue factory methods return Value<V> instead of S…

…coredValue<V> #1644

Nullable ScoredValue factory methods now declare Value as return type as an empty value cannot be associated without a score. Either both pieces of information should be present or absent but partial existence doesn't fit the programming model.

src/main/java/io/lettuce/core/GeoValue.java

@@ -47,12 +47,12 @@ private GeoValue(GeoCoordinates coordinates, V value) {
     }
 
     /**
-     * Creates a {@link GeoValue} from a {@code key} and an {@link Optional}. The resulting value contains the value from the
+     * Creates a {@link Value} from a {@code key} and an {@link Optional}. The resulting value contains the value from the
      * {@link Optional} if a value is present. Value is empty if the {@link Optional} is empty.
      *
-     * @param coordinates the score
+     * @param coordinates the score.
      * @param optional the optional. May be empty but never {@code null}.
-     * @return the {@link GeoValue}
+     * @return the {@link Value}.
      */
     public static <T extends V, V> Value<V> from(GeoCoordinates coordinates, Optional<T> optional) {
 
@@ -67,12 +67,12 @@ public static <T extends V, V> Value<V> from(GeoCoordinates coordinates, Optiona
     }
 
     /**
-     * Creates a {@link GeoValue} from a {@code coordinates} and {@code value}. The resulting value contains the value if the
+     * Creates a {@link Value} from a {@code coordinates} and {@code value}. The resulting value contains the value if the
      * {@code value} is not null.
      *
      * @param coordinates the coordinates.
      * @param value the value. May be {@code null}.
-     * @return the {@link GeoValue}
+     * @return the {@link Value}.
      */
     public static <T extends V, V> Value<V> fromNullable(GeoCoordinates coordinates, T value) {
 
@@ -101,7 +101,7 @@ public static <T extends V, V> GeoValue<V> just(double longitude, double latitud
      *
      * @param coordinates the coordinates.
      * @param value the value. Must not be {@code null}.
-     * @return the {@link GeoValue}
+     * @return the {@link GeoValue}.
      */
     public static <T extends V, V> GeoValue<V> just(GeoCoordinates coordinates, T value) {
 
@@ -170,9 +170,9 @@ public String toString() {
      * Returns a {@link GeoValue} consisting of the results of applying the given function to the value of this element. Mapping
      * is performed only if a {@link #hasValue() value is present}.
      *
-     * @param <R> The element type of the new stream
-     * @param mapper a stateless function to apply to each element
-     * @return the new {@link GeoValue}
+     * @param <R> element type of the new {@link GeoValue}.
+     * @param mapper a stateless function to apply to each element.
+     * @return the new {@link GeoValue}.
      */
     @SuppressWarnings("unchecked")
     public <R> GeoValue<R> map(Function<? super V, ? extends R> mapper) {
@@ -190,8 +190,8 @@ public <R> GeoValue<R> map(Function<? super V, ? extends R> mapper) {
      * Returns a {@link GeoValue} consisting of the results of applying the given function to the {@link GeoCoordinates} of this
      * element. Mapping is performed only if a {@link #hasValue() value is present}.
      *
-     * @param mapper a stateless function to apply to each element
-     * @return the new {@link GeoValue}
+     * @param mapper a stateless function to apply to each element.
+     * @return the new {@link GeoValue}.
      */
     public GeoValue<V> mapCoordinates(Function<? super GeoCoordinates, ? extends GeoCoordinates> mapper) {
 

src/main/java/io/lettuce/core/ScoredValue.java

@@ -27,7 +27,6 @@
  * @author Will Glozer
  * @author Mark Paluch
  */
-@SuppressWarnings("serial")
 public class ScoredValue<V> extends Value<V> {
 
     private static final ScoredValue<Object> EMPTY = new ScoredValue<>(0, null);
@@ -48,36 +47,36 @@ private ScoredValue(double score, V value) {
     }
 
     /**
-     * Creates a {@link ScoredValue} from a {@code key} and an {@link Optional}. The resulting value contains the value from the
+     * Creates a {@link Value} from a {@code key} and an {@link Optional}. The resulting value contains the value from the
      * {@link Optional} if a value is present. Value is empty if the {@link Optional} is empty.
      *
-     * @param score the score
+     * @param score the score.
      * @param optional the optional. May be empty but never {@code null}.
-     * @return the {@link ScoredValue}
+     * @return the {@link Value}.
      */
-    public static <T extends V, V> ScoredValue<V> from(double score, Optional<T> optional) {
+    public static <T extends V, V> Value<V> from(double score, Optional<T> optional) {
 
         LettuceAssert.notNull(optional, "Optional must not be null");
 
         if (optional.isPresent()) {
             return new ScoredValue<>(score, optional.get());
         }
 
-        return fromNullable(score, null);
+        return empty();
     }
 
     /**
-     * Creates a {@link ScoredValue} from a {@code score} and {@code value}. The resulting value contains the value if the
+     * Creates a {@link Value} from a {@code score} and {@code value}. The resulting value contains the value if the
      * {@code value} is not null.
      *
-     * @param score the score
+     * @param score the score.
      * @param value the value. May be {@code null}.
-     * @return the {@link ScoredValue}
+     * @return the {@link Value}.
      */
-    public static <T extends V, V> ScoredValue<V> fromNullable(double score, T value) {
+    public static <T extends V, V> Value<V> fromNullable(double score, T value) {
 
         if (value == null) {
-            return new ScoredValue<>(score, null);
+            return empty();
         }
 
         return new ScoredValue<>(score, value);
@@ -95,9 +94,9 @@ public static <V> ScoredValue<V> empty() {
     /**
      * Creates a {@link ScoredValue} from a {@code key} and {@code value}. The resulting value contains the value.
      *
-     * @param score the score
+     * @param score the score.
      * @param value the value. Must not be {@code null}.
-     * @return the {@link ScoredValue}
+     * @return the {@link ScoredValue}.
      */
     public static <T extends V, V> ScoredValue<V> just(double score, T value) {
 
@@ -143,9 +142,9 @@ public String toString() {
      * Returns a {@link ScoredValue} consisting of the results of applying the given function to the value of this element.
      * Mapping is performed only if a {@link #hasValue() value is present}.
      *
-     * @param <R> The element type of the new stream
-     * @param mapper a stateless function to apply to each element
-     * @return the new {@link ScoredValue}
+     * @param <R> element type of the new {@link ScoredValue}.
+     * @param mapper a stateless function to apply to each element.
+     * @return the new {@link ScoredValue}.
      */
     @SuppressWarnings("unchecked")
     public <R> ScoredValue<R> map(Function<? super V, ? extends R> mapper) {
@@ -163,8 +162,8 @@ public <R> ScoredValue<R> map(Function<? super V, ? extends R> mapper) {
      * Returns a {@link ScoredValue} consisting of the results of applying the given function to the score of this element.
      * Mapping is performed only if a {@link #hasValue() value is present}.
      *
-     * @param mapper a stateless function to apply to each element
-     * @return the new {@link ScoredValue}
+     * @param mapper a stateless function to apply to each element.
+     * @return the new {@link ScoredValue} .
      */
     @SuppressWarnings("unchecked")
     public ScoredValue<V> mapScore(Function<? super Number, ? extends Number> mapper) {

src/main/java/io/lettuce/core/Value.java

@@ -62,7 +62,7 @@ protected Value(V value) {
      * value is present. Value is empty if the {@link Optional} is empty.
      *
      * @param optional the optional. May be empty but never {@code null}.
-     * @return the {@link Value}
+     * @return the {@link Value}.
      */
     public static <T extends V, V> Value<V> from(Optional<T> optional) {
 
@@ -79,7 +79,7 @@ public static <T extends V, V> Value<V> from(Optional<T> optional) {
      * Creates a {@link Value} from a {@code value}. The resulting value contains the value if the {@code value} is not null.
      *
      * @param value the value. May be {@code null}.
-     * @return the {@link Value}
+     * @return the {@link Value}.
      */
     public static <T extends V, V> Value<V> fromNullable(T value) {
 
@@ -93,7 +93,7 @@ public static <T extends V, V> Value<V> fromNullable(T value) {
     /**
      * Returns an empty {@code Value} instance. No value is present for this instance.
      *
-     * @return the {@link Value}
+     * @return the {@link Value}.
      */
     public static <V> Value<V> empty() {
         return (Value<V>) EMPTY;
@@ -103,7 +103,7 @@ public static <V> Value<V> empty() {
      * Creates a {@link Value} from a {@code value}. The resulting value contains the value.
      *
      * @param value the value. Must not be {@code null}.
-     * @return the {@link Value}
+     * @return the {@link Value}.
      */
     public static <T extends V, V> Value<V> just(T value) {
 
@@ -137,8 +137,8 @@ public String toString() {
     /**
      * If a value is present in this {@code Value}, returns the value, otherwise throws {@code NoSuchElementException}.
      *
-     * @return the non-null value held by this {@code Optional}
-     * @throws NoSuchElementException if there is no value present
+     * @return the non-null value held by this {@code Optional}.
+     * @throws NoSuchElementException if there is no value present.
      *
      * @see Value#hasValue()
      */
@@ -154,7 +154,7 @@ public V getValue() {
     /**
      * Return {@code true} if there is a value present, otherwise {@code false}.
      *
-     * @return {@code true} if there is a value present, otherwise {@code false}
+     * @return {@code true} if there is a value present, otherwise {@code false}.
      */
     public boolean hasValue() {
         return value != null;
@@ -163,7 +163,7 @@ public boolean hasValue() {
     /**
      * Return {@code true} if there is no value present, otherwise {@code false}.
      *
-     * @return {@code true} if there is no value present, otherwise {@code false}
+     * @return {@code true} if there is no value present, otherwise {@code false}.
      * @since 6.1
      */
     public boolean isEmpty() {
@@ -174,8 +174,8 @@ public boolean isEmpty() {
      * Return the value if present, otherwise invoke {@code other} and return the result of that invocation.
      *
      * @param otherSupplier a {@code Supplier} whose result is returned if no value is present. Must not be {@code null}.
-     * @return the value if present otherwise the result of {@code other.get()}
-     * @throws NullPointerException if value is not present and {@code other} is null
+     * @return the value if present otherwise the result of {@code other.get()}.
+     * @throws NullPointerException if value is not present and {@code other} is null.
      */
     public V getValueOrElseGet(Supplier<V> otherSupplier) {
 
@@ -190,8 +190,8 @@ public V getValueOrElseGet(Supplier<V> otherSupplier) {
     /**
      * Return the value if present, otherwise return {@code other}.
      *
-     * @param other the value to be returned if there is no value present, may be null
-     * @return the value, if present, otherwise {@code other}
+     * @param other the value to be returned if there is no value present, may be null.
+     * @return the value, if present, otherwise {@code other}.
      */
     public V getValueOrElse(V other) {
 
@@ -225,9 +225,9 @@ public <X extends Throwable> V getValueOrElseThrow(Supplier<? extends X> excepti
      * Returns a {@link Value} consisting of the results of applying the given function to the value of this element. Mapping is
      * performed only if a {@link #hasValue() value is present}.
      *
-     * @param <R> The element type of the new value
-     * @param mapper a stateless function to apply to each element
-     * @return the new {@link Value}
+     * @param <R> The element type of the new value.
+     * @param mapper a stateless function to apply to each element.
+     * @return the new {@link Value}.
      */
     @SuppressWarnings("unchecked")
     public <R> Value<R> map(Function<? super V, ? extends R> mapper) {

src/main/java/io/lettuce/core/output/ScoredValueListOutput.java

@@ -19,10 +19,10 @@
 import java.util.Collections;
 import java.util.List;
 
-import io.lettuce.core.internal.LettuceStrings;
 import io.lettuce.core.ScoredValue;
 import io.lettuce.core.codec.RedisCodec;
 import io.lettuce.core.internal.LettuceAssert;
+import io.lettuce.core.internal.LettuceStrings;
 
 /**
  * {@link List} of values and their associated scores.
@@ -60,7 +60,7 @@ public void set(ByteBuffer bytes) {
     @Override
     public void set(double number) {
 
-        subscriber.onNext(output, ScoredValue.fromNullable(number, value));
+        subscriber.onNext(output, ScoredValue.just(number, value));
         value = null;
     }
 

src/main/java/io/lettuce/core/output/ScoredValueOutput.java

@@ -17,9 +17,9 @@
 
 import java.nio.ByteBuffer;
 
-import io.lettuce.core.internal.LettuceStrings;
 import io.lettuce.core.ScoredValue;
 import io.lettuce.core.codec.RedisCodec;
+import io.lettuce.core.internal.LettuceStrings;
 
 /**
  * A single {@link ScoredValue}.

src/main/java/io/lettuce/core/output/ScoredValueScanOutput.java

@@ -17,10 +17,10 @@
 
 import java.nio.ByteBuffer;
 
-import io.lettuce.core.internal.LettuceStrings;
 import io.lettuce.core.ScoredValue;
 import io.lettuce.core.ScoredValueScanCursor;
 import io.lettuce.core.codec.RedisCodec;
+import io.lettuce.core.internal.LettuceStrings;
 
 /**
  * {@link io.lettuce.core.ScoredValueScanCursor} for scan cursor output.
@@ -51,7 +51,9 @@ protected void setOutput(ByteBuffer bytes) {
 
     @Override
     public void set(double number) {
-        output.getValues().add(ScoredValue.fromNullable(number, value));
+        if (value != null) {
+            output.getValues().add(ScoredValue.just(number, value));
+        }
         value = null;
     }
 

src/main/java/io/lettuce/core/output/ScoredValueScanStreamingOutput.java

@@ -17,10 +17,10 @@
 
 import java.nio.ByteBuffer;
 
-import io.lettuce.core.internal.LettuceStrings;
 import io.lettuce.core.ScoredValue;
 import io.lettuce.core.StreamScanCursor;
 import io.lettuce.core.codec.RedisCodec;
+import io.lettuce.core.internal.LettuceStrings;
 
 /**
  * Streaming-Output of of values and their associated scores. Returns the count of all values (including null).
@@ -53,7 +53,11 @@ protected void setOutput(ByteBuffer bytes) {
 
     @Override
     public void set(double number) {
-        channel.onValue(ScoredValue.fromNullable(number, value));
+
+        if (value != null) {
+            channel.onValue(ScoredValue.just(number, value));
+        }
+
         value = null;
         output.setCount(output.getCount() + 1);
     }

src/main/java/io/lettuce/core/output/ScoredValueStreamingOutput.java

@@ -17,9 +17,9 @@
 
 import java.nio.ByteBuffer;
 
-import io.lettuce.core.internal.LettuceStrings;
 import io.lettuce.core.ScoredValue;
 import io.lettuce.core.codec.RedisCodec;
+import io.lettuce.core.internal.LettuceStrings;
 
 /**
  * Streaming-Output of of values and their associated scores. Returns the count of all values (including null).
@@ -54,7 +54,7 @@ public void set(ByteBuffer bytes) {
     @Override
     public void set(double number) {
 
-        channel.onValue(ScoredValue.fromNullable(number, value));
+        channel.onValue(ScoredValue.just(number, value));
         value = null;
         output = output.longValue() + 1;
     }