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vladimirsitnikov pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/calcite.git
The following commit(s) were added to refs/heads/master by this push:
new a3d02d2 Refactor Pair comparison to use Comparator.nullsFirst and
.naturalOrder()
a3d02d2 is described below
commit a3d02d2517e5cd7cc8d1da02309bdabe76ab195d
Author: Vladimir Sitnikov <[email protected]>
AuthorDate: Sat Sep 5 20:11:15 2020 +0300
Refactor Pair comparison to use Comparator.nullsFirst and .naturalOrder()
---
.../main/java/org/apache/calcite/util/Pair.java | 33 ++++++----------------
1 file changed, 8 insertions(+), 25 deletions(-)
diff --git a/core/src/main/java/org/apache/calcite/util/Pair.java
b/core/src/main/java/org/apache/calcite/util/Pair.java
index 9cd9c2e..26fa8cf 100644
--- a/core/src/main/java/org/apache/calcite/util/Pair.java
+++ b/core/src/main/java/org/apache/calcite/util/Pair.java
@@ -19,6 +19,7 @@ package org.apache.calcite.util;
import java.io.Serializable;
import java.util.AbstractList;
import java.util.Collections;
+import java.util.Comparator;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
@@ -39,6 +40,11 @@ import javax.annotation.Nonnull;
*/
public class Pair<T1, T2>
implements Comparable<Pair<T1, T2>>, Map.Entry<T1, T2>, Serializable {
+
+ @SuppressWarnings({"rawtypes", "unchecked"})
+ private static final Comparator NULLS_FIRST_COMPARATOR =
+ Comparator.nullsFirst((Comparator) Comparator.naturalOrder());
+
//~ Instance fields --------------------------------------------------------
public final T1 left;
@@ -100,10 +106,10 @@ public class Pair<T1, T2>
public int compareTo(@Nonnull Pair<T1, T2> that) {
//noinspection unchecked
- int c = compare((Comparable) this.left, (Comparable) that.left);
+ int c = NULLS_FIRST_COMPARATOR.compare(this.left, that.left);
if (c == 0) {
//noinspection unchecked
- c = compare((Comparable) this.right, (Comparable) that.right);
+ c = NULLS_FIRST_COMPARATOR.compare(this.right, that.right);
}
return c;
}
@@ -125,29 +131,6 @@ public class Pair<T1, T2>
}
/**
- * Compares a pair of comparable values of the same type. Null collates
- * less than everything else, but equal to itself.
- *
- * @param c1 First value
- * @param c2 Second value
- * @return a negative integer, zero, or a positive integer if c1
- * is less than, equal to, or greater than c2.
- */
- private static <C extends Comparable<C>> int compare(C c1, C c2) {
- if (c1 == null) {
- if (c2 == null) {
- return 0;
- } else {
- return -1;
- }
- } else if (c2 == null) {
- return 1;
- } else {
- return c1.compareTo(c2);
- }
- }
-
- /**
* Converts a collection of Pairs into a Map.
*
* <p>This is an obvious thing to do because Pair is similar in structure to
