Update?

2 files changed, 15 insertions, 3 deletions

diff --git a/TODO.txt b/TODO.txt
new file mode 100644
index 0000000..ee3175d
--- /dev/null
+++ b/TODO.txt
@@ -0,0 +1,5 @@
+@TODO, Oct 17th, 2020 - Ben Culkin - :ExceptionOverview
+	Go over all of the code and make sure that the exceptions we are throwing
+	are of the right type, and have a useful message. In some contexts, this may
+	mean creating some wrapper exception types, just to make it clear what
+	exactly has gone wrong
diff --git a/src/main/java/bjc/data/Tree.java b/src/main/java/bjc/data/Tree.java
index 9a4caa6..5337af5 100644
--- a/src/main/java/bjc/data/Tree.java
+++ b/src/main/java/bjc/data/Tree.java
@@ -227,9 +227,6 @@ public class Tree<ContainedType> implements ITree<ContainedType> {
 
 	/*
 	 * Do a collapse of this tree.
-	 *
-	 * @NOTE Why is this protected? I can't see any good reason someone'd want to
-	 * override it.
 	 */
 
 	private <NewType> NewType internalCollapse(
@@ -381,6 +378,16 @@ public class Tree<ContainedType> implements ITree<ContainedType> {
 	}
 
 	@Override
+	public ITree<ContainedType> getChild(final int childNo) {
+		if (childNo < 0 || childNo > childCount - 1) {
+			final String msg = String.format("Child index #%d is invalid", childNo);
+
+			throw new IllegalArgumentException(msg);
+		}
+		return children.getByIndex(childNo);
+	}
+
+	@Override
 	public <TransformedType> TransformedType
 			transformHead(final Function<ContainedType, TransformedType> transformer) {
 		return transformer.apply(data);