1 files changed, 175 insertions, 0 deletions
diff --git a/src/main/java/bjc/funcdata/FunctionalMap.java b/src/main/java/bjc/funcdata/FunctionalMap.java
new file mode 100644
index 0000000..fc53829
--- /dev/null
+++ b/src/main/java/bjc/funcdata/FunctionalMap.java
@@ -0,0 +1,175 @@
+package bjc.funcdata;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.BiConsumer;
+import java.util.function.Consumer;
+import java.util.function.Function;
+
+import bjc.data.IPair;
+
+/**
+ * Basic implementation of {@link IMap}
+ *
+ * @author ben
+ *
+ * @param <KeyType>
+ *        The type of the map's keys.
+ *
+ * @param <ValueType>
+ *        The type of the map's values.
+ */
+public class FunctionalMap<KeyType, ValueType> implements IMap<KeyType, ValueType> {
+	/* Our backing store. */
+	private Map<KeyType, ValueType> wrappedMap;
+
+	/** Create a new blank functional map */
+	public FunctionalMap() {
+		wrappedMap = new HashMap<>();
+	}
+
+	/**
+	 * Create a new functional map with the specified entries.
+	 *
+	 * @param entries
+	 *        The entries to put into the map.
+	 */
+	@SafeVarargs
+	public FunctionalMap(final IPair<KeyType, ValueType>... entries) {
+		this();
+
+		for(final IPair<KeyType, ValueType> entry : entries) {
+			entry.doWith((key, val) -> {
+				wrappedMap.put(key, val);
+			});
+		}
+	}
+
+	/**
+	 * Create a new functional map wrapping the specified map.
+	 *
+	 * @param wrap
+	 *        The map to wrap.
+	 */
+	public FunctionalMap(final Map<KeyType, ValueType> wrap) {
+		if(wrap == null) throw new NullPointerException("Map to wrap must not be null");
+
+		wrappedMap = wrap;
+	}
+
+	@Override
+	public void clear() {
+		wrappedMap.clear();
+	}
+
+	@Override
+	public boolean containsKey(final KeyType key) {
+		return wrappedMap.containsKey(key);
+	}
+
+	@Override
+	public IMap<KeyType, ValueType> extend() {
+		return new ExtendedMap<>(this, new FunctionalMap<>());
+	}
+
+	@Override
+	public void forEach(final BiConsumer<KeyType, ValueType> action) {
+		wrappedMap.forEach(action);
+	}
+
+	@Override
+	public void forEachKey(final Consumer<KeyType> action) {
+		wrappedMap.keySet().forEach(action);
+	}
+
+	@Override
+	public void forEachValue(final Consumer<ValueType> action) {
+		wrappedMap.values().forEach(action);
+	}
+
+	@Override
+	public ValueType get(final KeyType key) {
+		if(key == null) throw new NullPointerException("Key must not be null");
+
+		if(!wrappedMap.containsKey(key)) {
+			final String msg = String.format("Key %s is not present in the map", key);
+
+			throw new IllegalArgumentException(msg);
+		}
+
+		return wrappedMap.get(key);
+	}
+
+	@Override
+	public int size() {
+		return wrappedMap.size();
+	}
+
+	@Override
+	public IList<KeyType> keyList() {
+		final FunctionalList<KeyType> keys = new FunctionalList<>();
+
+		wrappedMap.keySet().forEach(key -> {
+			keys.add(key);
+		});
+
+		return keys;
+	}
+
+	@Override
+	public <MappedValue> IMap<KeyType, MappedValue> transform(final Function<ValueType, MappedValue> transformer) {
+		if(transformer == null) throw new NullPointerException("Transformer must not be null");
+
+		return new TransformedValueMap<>(this, transformer);
+	}
+
+	@Override
+	public ValueType put(final KeyType key, final ValueType val) {
+		if(key == null) throw new NullPointerException("Key must not be null");
+
+		return wrappedMap.put(key, val);
+	}
+
+	@Override
+	public ValueType remove(final KeyType key) {
+		return wrappedMap.remove(key);
+	}
+
+	@Override
+	public String toString() {
+		return wrappedMap.toString();
+	}
+
+	@Override
+	public IList<ValueType> valueList() {
+		final FunctionalList<ValueType> values = new FunctionalList<>();
+
+		wrappedMap.values().forEach(value -> {
+			values.add(value);
+		});
+
+		return values;
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+		int result = 1;
+		result = prime * result + (wrappedMap == null ? 0 : wrappedMap.hashCode());
+		return result;
+	}
+
+	@Override
+	public boolean equals(final Object obj) {
+		if(this == obj) return true;
+		if(obj == null) return false;
+		if(!(obj instanceof FunctionalMap)) return false;
+
+		final FunctionalMap<?, ?> other = (FunctionalMap<?, ?>) obj;
+
+		if(wrappedMap == null) {
+			if(other.wrappedMap != null) return false;
+		} else if(!wrappedMap.equals(other.wrappedMap)) return false;
+		return true;
+	}
+}