1 files changed, 92 insertions, 0 deletions
diff --git a/dice-lang/src/main/java/bjc/dicelang/ast/DiceASTFreezer.java b/dice-lang/src/main/java/bjc/dicelang/ast/DiceASTFreezer.java
new file mode 100644
index 0000000..0e2134b
--- /dev/null
+++ b/dice-lang/src/main/java/bjc/dicelang/ast/DiceASTFreezer.java
@@ -0,0 +1,92 @@
+package bjc.dicelang.ast;
+
+import java.util.Map;
+
+import bjc.utils.parserutils.AST;
+
+/**
+ * Freeze references in a dice AST, replacing variable references with what
+ * the variables refer to
+ * 
+ * @author ben
+ *
+ */
+public class DiceASTFreezer {
+	/**
+	 * Expand a reference
+	 * 
+	 * @param vnode
+	 *            The node containing the reference to expand
+	 * @param env
+	 *            The enviroment to expand against
+	 * @return The expanded reference
+	 */
+	private static AST<IDiceASTNode> expandNode(VariableDiceNode vnode,
+			Map<String, AST<IDiceASTNode>> env) {
+		return env.get(vnode.getVariable());
+	}
+
+	/**
+	 * Expand a reference
+	 * 
+	 * @param vnode
+	 *            The node containing the reference to expand
+	 * @param env
+	 *            The enviroment to expand against
+	 * @return The expanded reference
+	 */
+	private static AST<IDiceASTNode> expandNode2(VariableDiceNode vnode,
+			Map<String, DiceASTExpression> env) {
+		return env.get(vnode.getVariable()).getAst();
+	}
+
+	/**
+	 * Freeze the references in an AST
+	 * 
+	 * @param tree
+	 *            The tree to freeze references in
+	 * @param env
+	 *            The enviroment to get reference values from
+	 * @return The tree with references frozen
+	 */
+	@SuppressWarnings("unused")
+	public static AST<IDiceASTNode> freezeAST(AST<IDiceASTNode> tree,
+			Map<String, AST<IDiceASTNode>> env) {
+		return tree.collapse((nod) -> {
+			if (nod instanceof VariableDiceNode) {
+				return expandNode((VariableDiceNode) nod, env);
+			} else {
+				// Type is specified here so compiler can know the type
+				// we're using
+				return new AST<IDiceASTNode>(nod);
+			}
+		} , (op) -> (left, right) -> {
+			return new AST<IDiceASTNode>(op, left, right);
+		} , (r) -> r);
+	}
+
+	/**
+	 * Freeze the references in an expression backed by an AST
+	 * 
+	 * @param tree
+	 *            The tree-backed expression to freeze references in
+	 * @param env
+	 *            The enviroment to get reference values from
+	 * @return The tree with references frozen
+	 */
+	@SuppressWarnings("unused")
+	public static AST<IDiceASTNode> freezeAST(DiceASTExpression tree,
+			Map<String, DiceASTExpression> env) {
+		return tree.getAst().collapse((nod) -> {
+			if (nod instanceof VariableDiceNode) {
+				return expandNode2((VariableDiceNode) nod, env);
+			} else {
+				// Type is specified here so compiler can know the type
+				// we're using
+				return new AST<IDiceASTNode>(nod);
+			}
+		} , (op) -> (left, right) -> {
+			return new AST<IDiceASTNode>(op, left, right);
+		} , (r) -> r);
+	}
+}