1 files changed, 102 insertions, 0 deletions
diff --git a/base/src/main/java/bjc/utils/funcdata/TransformedValueMap.java b/base/src/main/java/bjc/utils/funcdata/TransformedValueMap.java
new file mode 100644
index 0000000..0ca1fdc
--- /dev/null
+++ b/base/src/main/java/bjc/utils/funcdata/TransformedValueMap.java
@@ -0,0 +1,102 @@
+package bjc.utils.funcdata;
+
+import java.util.function.BiConsumer;
+import java.util.function.Consumer;
+import java.util.function.Function;
+
+/**
+ * A map that transforms values from one type to another
+ *
+ * @author ben
+ *
+ * @param <OldKey>
+ *                The type of the map's keys
+ * @param <OldValue>
+ *                The type of the map's values
+ * @param <NewValue>
+ *                The type of the transformed values
+ */
+final class TransformedValueMap<OldKey, OldValue, NewValue> implements IMap<OldKey, NewValue> {
+	private final IMap<OldKey, OldValue>		backing;
+	private final Function<OldValue, NewValue>	transformer;
+
+	public TransformedValueMap(final IMap<OldKey, OldValue> backingMap,
+			final Function<OldValue, NewValue> transform) {
+		backing = backingMap;
+		transformer = transform;
+	}
+
+	@Override
+	public void clear() {
+		backing.clear();
+	}
+
+	@Override
+	public boolean containsKey(final OldKey key) {
+		return backing.containsKey(key);
+	}
+
+	@Override
+	public IMap<OldKey, NewValue> extend() {
+		return new ExtendedMap<>(this, new FunctionalMap<>());
+	}
+
+	@Override
+	public void forEach(final BiConsumer<OldKey, NewValue> action) {
+		backing.forEach((key, value) -> {
+			action.accept(key, transformer.apply(value));
+		});
+	}
+
+	@Override
+	public void forEachKey(final Consumer<OldKey> action) {
+		backing.forEachKey(action);
+	}
+
+	@Override
+	public void forEachValue(final Consumer<NewValue> action) {
+		backing.forEachValue(value -> {
+			action.accept(transformer.apply(value));
+		});
+	}
+
+	@Override
+	public NewValue get(final OldKey key) {
+		return transformer.apply(backing.get(key));
+	}
+
+	@Override
+	public int size() {
+		return backing.size();
+	}
+
+	@Override
+	public IList<OldKey> keyList() {
+		return backing.keyList();
+	}
+
+	@Override
+	public <MappedValue> IMap<OldKey, MappedValue> transform(final Function<NewValue, MappedValue> transform) {
+		return new TransformedValueMap<>(this, transform);
+	}
+
+	@Override
+	public NewValue put(final OldKey key, final NewValue value) {
+		throw new UnsupportedOperationException("Can't add items to transformed map");
+	}
+
+	@Override
+	public NewValue remove(final OldKey key) {
+		return transformer.apply(backing.remove(key));
+	}
+
+	@Override
+	public String toString() {
+		return backing.toString();
+	}
+
+	@Override
+	public IList<NewValue> valueList() {
+		return backing.valueList().map(transformer);
+	}
+}