1 files changed, 70 insertions, 0 deletions
diff --git a/dice-lang/src/main/java/bjc/dicelang/ReferenceDiceExpression.java b/dice-lang/src/main/java/bjc/dicelang/ReferenceDiceExpression.java
new file mode 100644
index 0000000..c1a4a79
--- /dev/null
+++ b/dice-lang/src/main/java/bjc/dicelang/ReferenceDiceExpression.java
@@ -0,0 +1,70 @@
+package bjc.dicelang;
+
+import java.util.Map;
+
+/**
+ * A dice expression that refers to a variable bound in a mutable
+ * enviroment
+ * 
+ * @author ben
+ *
+ */
+public class ReferenceDiceExpression implements IDiceExpression {
+	/**
+	 * The enviroment to do variable dereferencing against
+	 */
+	private Map<String, IDiceExpression>	env;
+
+	/**
+	 * The name of the bound variable
+	 */
+	private String							name;
+
+	/**
+	 * Create a new reference dice expression referring to the given name
+	 * in an enviroment
+	 * 
+	 * @param name
+	 *            The name of the bound variable
+	 * @param env
+	 *            The enviroment to resolve the variable against
+	 */
+	public ReferenceDiceExpression(String name,
+			Map<String, IDiceExpression> env) {
+		this.name = name;
+		this.env = env;
+	}
+
+	/**
+	 * Get the name of the referenced variable
+	 * 
+	 * @return the name of the referenced variable
+	 */
+	public String getName() {
+		return name;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see bjc.utils.dice.IDiceExpression#roll()
+	 */
+	@Override
+	public int roll() {
+		return env.get(name).roll();
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see java.lang.Object#toString()
+	 */
+	@Override
+	public String toString() {
+		if (env.containsKey(name)) {
+			return env.get(name).toString();
+		} else {
+			return name;
+		}
+	}
+}