1 files changed, 52 insertions, 0 deletions
diff --git a/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/UnaryCommand.java b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/UnaryCommand.java
new file mode 100644
index 0000000..a7efdc3
--- /dev/null
+++ b/JPratt/src/main/java/com/ashardalon/pratt/commands/impls/UnaryCommand.java
@@ -0,0 +1,52 @@
+package com.ashardalon.pratt.commands.impls;
+
+import bjc.data.Tree;
+
+import com.ashardalon.pratt.ParserContext;
+import com.ashardalon.pratt.commands.AbstractInitialCommand;
+import com.ashardalon.pratt.commands.CommandResult;
+import com.ashardalon.pratt.commands.CommandResult.Status;
+import com.ashardalon.pratt.tokens.Token;
+
+import bjc.data.SimpleTree;
+import bjc.utils.parserutils.ParserException;
+
+/**
+ * A unary operator.
+ *
+ * @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 UnaryCommand<K, V, C> extends AbstractInitialCommand<K, V, C> {
+	private final int nullPwer;
+
+	/**
+	 * Create a new unary command.
+	 *
+	 * @param precedence
+	 *        The precedence of this operator.
+	 */
+	public UnaryCommand(final int precedence) {
+		if(precedence < 0) throw new IllegalArgumentException("Precedence must be non-negative");
+
+		nullPwer = precedence;
+	}
+
+	@Override
+	protected CommandResult<K, V> intNullDenotation(final Token<K, V> operator, final ParserContext<K, V, C> ctx)
+			throws ParserException {
+		CommandResult<K,V> result = ctx.parse.parseExpression(nullPwer, ctx.tokens, ctx.state, false);
+		if (result.status != Status.SUCCESS) return result;
+		final Tree<Token<K, V>> opr = result.success();
+
+		return CommandResult.success(new SimpleTree<>(operator, opr));
+	}
+}
+\ No newline at end of file