ToMap is covariant in Entry position

jnape · jnape · commit 04d738d8d883 · 2018-05-07T21:28:36.000-05:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -4,7 +4,8 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/).
 
 ## [Unreleased]
-_No changes_
+### Changed
+- `ToMap` accepts an `Iterable` covariant in `Map.Entry`
 
 ## [3.0.0] - 2018-05-04
 ### Changed
diff --git a/src/main/java/com/jnape/palatable/lambda/functions/builtin/fn2/ToMap.java b/src/main/java/com/jnape/palatable/lambda/functions/builtin/fn2/ToMap.java
@@ -17,15 +17,15 @@
  * @param <V> the value element type
  * @param <M> the resulting map type
  */
-public final class ToMap<K, V, M extends Map<K, V>> implements Fn2<Supplier<M>, Iterable<Map.Entry<K, V>>, M> {
+public final class ToMap<K, V, M extends Map<K, V>> implements Fn2<Supplier<M>, Iterable<? extends Map.Entry<K, V>>, M> {
 
     private static final ToMap INSTANCE = new ToMap<>();
 
     private ToMap() {
     }
 
     @Override
-    public M apply(Supplier<M> mSupplier, Iterable<Map.Entry<K, V>> entries) {
+    public M apply(Supplier<M> mSupplier, Iterable<? extends Map.Entry<K, V>> entries) {
         return foldLeft((m, kv) -> {
             m.put(kv.getKey(), kv.getValue());
             return m;
@@ -37,11 +37,12 @@ public static <K, V, M extends Map<K, V>> ToMap<K, V, M> toMap() {
         return INSTANCE;
     }
 
-    public static <K, V, M extends Map<K, V>> Fn1<Iterable<Map.Entry<K, V>>, M> toMap(Supplier<M> mSupplier) {
+    public static <K, V, M extends Map<K, V>> Fn1<Iterable<? extends Map.Entry<K, V>>, M> toMap(Supplier<M> mSupplier) {
         return ToMap.<K, V, M>toMap().apply(mSupplier);
     }
 
-    public static <K, V, M extends Map<K, V>> M toMap(Supplier<M> mSupplier, Iterable<Map.Entry<K, V>> entries) {
+    public static <K, V, M extends Map<K, V>> M toMap(Supplier<M> mSupplier,
+                                                      Iterable<? extends Map.Entry<K, V>> entries) {
         return toMap(mSupplier).apply(entries);
     }
 }

Original file line number	Diff line number	Diff line change
`@@ -17,15 +17,15 @@`
`17`	`17`	`* @param <V> the value element type`
`18`	`18`	`* @param <M> the resulting map type`
`19`	`19`	`*/`
`20`		`-public final class ToMap<K, V, M extends Map<K, V>> implements Fn2<Supplier<M>, Iterable<Map.Entry<K, V>>, M> {`
	`20`	`+public final class ToMap<K, V, M extends Map<K, V>> implements Fn2<Supplier<M>, Iterable<? extends Map.Entry<K, V>>, M> {`
`21`	`21`
`22`	`22`	`private static final ToMap INSTANCE = new ToMap<>();`
`23`	`23`
`24`	`24`	`private ToMap() {`
`25`	`25`	`}`
`26`	`26`
`27`	`27`	`@Override`
`28`		`- public M apply(Supplier<M> mSupplier, Iterable<Map.Entry<K, V>> entries) {`
	`28`	`+ public M apply(Supplier<M> mSupplier, Iterable<? extends Map.Entry<K, V>> entries) {`
`29`	`29`	`return foldLeft((m, kv) -> {`
`30`	`30`	`m.put(kv.getKey(), kv.getValue());`
`31`	`31`	`return m;`
`@@ -37,11 +37,12 @@ public static <K, V, M extends Map<K, V>> ToMap<K, V, M> toMap() {`
`37`	`37`	`return INSTANCE;`
`38`	`38`	`}`
`39`	`39`
`40`		`- public static <K, V, M extends Map<K, V>> Fn1<Iterable<Map.Entry<K, V>>, M> toMap(Supplier<M> mSupplier) {`
	`40`	`+ public static <K, V, M extends Map<K, V>> Fn1<Iterable<? extends Map.Entry<K, V>>, M> toMap(Supplier<M> mSupplier) {`
`41`	`41`	`return ToMap.<K, V, M>toMap().apply(mSupplier);`
`42`	`42`	`}`
`43`	`43`
`44`		`- public static <K, V, M extends Map<K, V>> M toMap(Supplier<M> mSupplier, Iterable<Map.Entry<K, V>> entries) {`
	`44`	`+ public static <K, V, M extends Map<K, V>> M toMap(Supplier<M> mSupplier,`
	`45`	`+ Iterable<? extends Map.Entry<K, V>> entries) {`
`45`	`46`	`return toMap(mSupplier).apply(entries);`
`46`	`47`	`}`
`47`	`48`	`}`