Factored interface out of GenHolder

2 files changed, 62 insertions, 20 deletions

diff --git a/BJC-Utils2/src/main/java/bjc/utils/data/GenHolder.java b/BJC-Utils2/src/main/java/bjc/utils/data/GenHolder.java
index 390982a..d6266ca 100644
--- a/BJC-Utils2/src/main/java/bjc/utils/data/GenHolder.java
+++ b/BJC-Utils2/src/main/java/bjc/utils/data/GenHolder.java
@@ -7,12 +7,14 @@ import java.util.function.Function;
  * references to data, and more specifically for accessing non-final
  * variables from a lambda. AKA the identity monad
  * 
+ * This is an eager variant of {@link IHolder}
+ * 
  * @author ben
  *
  * @param <T>
  *            The type of the data being held
  */
-public class GenHolder<T> {
+public class GenHolder<T> implements IHolder<T> {
 	/**
 	 * The state this holder is responsible for.
 	 */
@@ -36,39 +38,34 @@ public class GenHolder<T> {
 		held = hld;
 	}
 
-	/**
-	 * Return the result of applying the given transformation to the held
-	 * value Doesn't change the held value
+	/*
+	 * (non-Javadoc)
 	 * 
-	 * @param f
-	 *            The transformation to apply
-	 * @return A holder with the transformed value
+	 * @see bjc.utils.data.IHolder#map(java.util.function.Function)
 	 */
-	public <NewT> GenHolder<NewT> map(Function<T, NewT> f) {
+	@Override
+	public <NewT> IHolder<NewT> map(Function<T, NewT> f) {
 		return new GenHolder<NewT>(f.apply(held));
 	}
 
-	/**
-	 * Apply the given transformation to the held value. Returns the holder
-	 * for allowing chaining of transforms
+	/*
+	 * (non-Javadoc)
 	 * 
-	 * @param f
-	 *            The transform to apply to the value
-	 * @return The holder
+	 * @see bjc.utils.data.IHolder#transform(java.util.function.Function)
 	 */
-	public GenHolder<T> transform(Function<T, T> f) {
+	@Override
+	public IHolder<T> transform(Function<T, T> f) {
 		held = f.apply(held);
 
 		return this;
 	}
 
-	/**
-	 * Returns a raw mapped value, not contained in a GenHolder
+	/*
+	 * (non-Javadoc)
 	 * 
-	 * @param f
-	 *            The function to use for mapping the value
-	 * @return The mapped value outside of a GenHolder
+	 * @see bjc.utils.data.IHolder#unwrap(java.util.function.Function)
 	 */
+	@Override
 	public <E> E unwrap(Function<T, E> f) {
 		return f.apply(held);
 	}
diff --git a/BJC-Utils2/src/main/java/bjc/utils/data/IHolder.java b/BJC-Utils2/src/main/java/bjc/utils/data/IHolder.java
new file mode 100644
index 0000000..aa7d5bd
--- /dev/null
+++ b/BJC-Utils2/src/main/java/bjc/utils/data/IHolder.java
@@ -0,0 +1,45 @@
+package bjc.utils.data;
+
+import java.util.function.Function;
+
+/**
+ * Generic interface for things that store a single value in a roughly
+ * monadic fashion
+ * 
+ * @author ben
+ *
+ * @param <T>
+ *            The type of data being stored
+ */
+public interface IHolder<T> {
+
+	/**
+	 * Return the result of applying the given transformation to the held
+	 * value Doesn't change the held value
+	 * 
+	 * @param f
+	 *            The transformation to apply
+	 * @return A holder with the transformed value
+	 */
+	<NewT> IHolder<NewT> map(Function<T, NewT> f);
+
+	/**
+	 * Apply the given transformation to the held value. Returns the holder
+	 * for allowing chaining of transforms
+	 * 
+	 * @param f
+	 *            The transform to apply to the value
+	 * @return The holder
+	 */
+	IHolder<T> transform(Function<T, T> f);
+
+	/**
+	 * Returns a raw mapped value, not contained in a GenHolder
+	 * 
+	 * @param f
+	 *            The function to use for mapping the value
+	 * @return The mapped value outside of a GenHolder
+	 */
+	<E> E unwrap(Function<T, E> f);
+
+}
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