Misc fixes

+ Alter nullity annotation order + Reimplement UniquelyOccurringGatherer to use LinkedHashSet
tginsberg · Jan 22, 2025 · 31006b0 · 31006b0
1 parent a21f3a8
commit 31006b0
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Showing 7 changed files with 17 additions and 23 deletions.
diff --git a/README.md b/README.md
@@ -38,7 +38,7 @@ implementation("com.ginsberg:gatherers4j:0.8.0")
 | `dedupeConsecutiveBy(fn)`      | Remove consecutive duplicates from a stream as returned by `fn`                                                                |
 | `distinctBy(fn)`               | Emit only distinct elements from the stream, as measured by `fn`                                                               |
 | `dropLast(n)`                  | Keep all but the last `n` elements of the stream                                                                               |
-| `everyNth(n)`                  | Limit the stream to every `n`<sup>th</sup> element                                                                                        |
+| `everyNth(n)`                  | Limit the stream to every `n`<sup>th</sup> element                                                                             |
 | `filterWithIndex(predicate)`   | Filter the stream with the given `predicate`, which takes an `element` and its `index`                                         |
 | `grouping()`                   | Group consecutive identical elements into lists                                                                                |
 | `groupingBy(fn)`               | Group consecutive elements that are identical according to `fn` into lists                                                     |                                                                                                                    

diff --git a/src/main/java/com/ginsberg/gatherers4j/BigDecimalGatherer.java b/src/main/java/com/ginsberg/gatherers4j/BigDecimalGatherer.java
@@ -58,7 +58,7 @@ public BigDecimalGatherer<INPUT> treatNullAsZero() {
     /// When encountering a `null` value in a stream, treat it as the given `replacement` value instead.
     ///
     /// @param replacement The value to replace `null` with
-    public BigDecimalGatherer<INPUT> treatNullAs(final @Nullable BigDecimal replacement) {
+    public BigDecimalGatherer<INPUT> treatNullAs(@Nullable final BigDecimal replacement) {
         this.nullReplacement = replacement;
         return this;
     }

diff --git a/src/main/java/com/ginsberg/gatherers4j/DedupeConsecutiveGatherer.java b/src/main/java/com/ginsberg/gatherers4j/DedupeConsecutiveGatherer.java
@@ -26,9 +26,10 @@
 public class DedupeConsecutiveGatherer<INPUT extends @Nullable Object>
         implements Gatherer<INPUT, DedupeConsecutiveGatherer.State, INPUT> {
 
-    private final @Nullable Function<INPUT, @Nullable Object> mappingFunction;
+    @Nullable
+    private final Function<INPUT, @Nullable Object> mappingFunction;
 
-    DedupeConsecutiveGatherer(final @Nullable Function<INPUT, @Nullable Object> mappingFunction) {
+    DedupeConsecutiveGatherer(@Nullable final Function<INPUT, @Nullable Object> mappingFunction) {
         this.mappingFunction = mappingFunction;
     }
 

diff --git a/src/main/java/com/ginsberg/gatherers4j/GathererUtils.java b/src/main/java/com/ginsberg/gatherers4j/GathererUtils.java
@@ -21,13 +21,13 @@ abstract class GathererUtils {
 
     final static long NANOS_PER_MILLISECOND = 1_000_000;
 
-    static void mustNotBeNull(final @Nullable Object subject, final String message) {
+    static void mustNotBeNull(@Nullable final Object subject, final String message) {
         if (subject == null) {
             throw new IllegalArgumentException(message);
         }
     }
 
-    static boolean safeEquals(final @Nullable Object left, final @Nullable Object right) {
+    static boolean safeEquals(@Nullable final Object left, @Nullable final Object right) {
         if (left == null && right == null) {
             return true;
         } else if (left == null || right == null) {

diff --git a/src/main/java/com/ginsberg/gatherers4j/GroupingByGatherer.java b/src/main/java/com/ginsberg/gatherers4j/GroupingByGatherer.java
@@ -31,7 +31,8 @@
 public class GroupingByGatherer<INPUT extends @Nullable Object> implements
         Gatherer<INPUT, GroupingByGatherer.State<INPUT>, List<INPUT>> {
 
-    private final @Nullable Function<INPUT, Object> mappingFunction;
+    @Nullable
+    private final Function<INPUT, Object> mappingFunction;
 
     GroupingByGatherer() {
         mappingFunction = null;

diff --git a/src/main/java/com/ginsberg/gatherers4j/UniquelyOccurringGatherer.java b/src/main/java/com/ginsberg/gatherers4j/UniquelyOccurringGatherer.java
@@ -18,9 +18,8 @@
 
 import org.jspecify.annotations.Nullable;
 
-import java.util.HashMap;
 import java.util.HashSet;
-import java.util.Map;
+import java.util.LinkedHashSet;
 import java.util.Set;
 import java.util.function.BiConsumer;
 import java.util.function.Supplier;
@@ -41,12 +40,12 @@ public Supplier<State<INPUT>> initializer() {
     @Override
     public Integrator<State<INPUT>, INPUT, INPUT> integrator() {
         return Integrator.ofGreedy((state, element, downstream) -> {
-            if (!state.knownBad.contains(element)) {
-                if (state.found.containsKey(element)) {
-                    state.knownBad.add(element);
+            if (!state.duplicates.contains(element)) {
+                if (state.found.contains(element)) {
+                    state.duplicates.add(element);
                     state.found.remove(element);
                 } else {
-                    state.found.put(element, state.iteration++);
+                    state.found.add(element);
                 }
             }
             return !downstream.isRejecting();
@@ -55,17 +54,11 @@ public Integrator<State<INPUT>, INPUT, INPUT> integrator() {
 
     @Override
     public BiConsumer<State<INPUT>, Downstream<? super INPUT>> finisher() {
-        return (inputState, downstream) ->
-            inputState.found
-                    .entrySet()
-                    .stream()
-                    .sorted((a, b) -> (int) (a.getValue() - b.getValue()))
-                    .forEach(it -> downstream.push(it.getKey()));
+        return (inputState, downstream) -> inputState.found.forEach(downstream::push);
     }
 
     public static class State<INPUT> {
-        long iteration = 0;
-        final Set<INPUT> knownBad = new HashSet<>();
-        final Map<INPUT, Long> found = new HashMap<>();
+        final Set<INPUT> duplicates = new HashSet<>();
+        final Set<INPUT> found = new LinkedHashSet<>();
     }
 }
diff --git a/src/test/java/com/ginsberg/gatherers4j/EveryNthGathererTest.java b/src/test/java/com/ginsberg/gatherers4j/EveryNthGathererTest.java
@@ -23,7 +23,6 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.junit.jupiter.api.Assertions.*;
 
 class EveryNthGathererTest {