1 files changed, 59 insertions, 0 deletions
diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/TransformingInitialCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/TransformingInitialCommand.java
new file mode 100644
index 0000000..9a08c44
--- /dev/null
+++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/TransformingInitialCommand.java
@@ -0,0 +1,59 @@
+package com.ashardalon.pratt.commands.impls;
+
+import java.util.function.UnaryOperator;
+
+import com.ashardalon.pratt.ParserContext;
+import com.ashardalon.pratt.commands.AbstractInitialCommand;
+import com.ashardalon.pratt.commands.CommandResult;
+import com.ashardalon.pratt.commands.InitialCommand;
+import com.ashardalon.pratt.commands.CommandResult.Status;
+import com.ashardalon.pratt.tokens.Token;
+
+import bjc.data.Tree;
+import bjc.utils.parserutils.ParserException;
+
+/**
+ * An initial command that transforms the result of another command.
+ *
+ * @author bjculkin
+ *
+ * @param <K>
+ *        The key type of the tokens.
+ *
+ * @param <V>
+ *        The value type of the tokens.
+ *
+ * @param <C>
+ *        The state type of the parser.
+ */
+public class TransformingInitialCommand<K, V, C> extends AbstractInitialCommand<K, V, C> {
+	private final InitialCommand<K, V, C> internl;
+
+	private final UnaryOperator<Tree<Token<K, V>>> transfrm;
+
+	/**
+	 * Create a new transforming initial command.
+	 *
+	 * @param internal
+	 *        The initial command to delegate to.
+	 *
+	 * @param transform
+	 *        The transform to apply to the returned tree.
+	 */
+	public TransformingInitialCommand(final InitialCommand<K, V, C> internal,
+			final UnaryOperator<Tree<Token<K, V>>> transform) {
+		super();
+		internl = internal;
+		transfrm = transform;
+	}
+
+	@Override
+	protected CommandResult<K, V> intNullDenotation(final Token<K, V> operator, final ParserContext<K, V, C> ctx)
+			throws ParserException {
+		CommandResult<K,V> result = internl.denote(operator, ctx);
+		if (result.status != Status.SUCCESS) return result;
+		
+		return CommandResult.success(transfrm.apply(result.success()));
+	}
+
+}