1 files changed, 91 insertions, 0 deletions
diff --git a/dice-lang/src/bjc/dicelang/ast/optimization/ConstantCollapser.java b/dice-lang/src/bjc/dicelang/ast/optimization/ConstantCollapser.java
new file mode 100644
index 0000000..95badd2
--- /dev/null
+++ b/dice-lang/src/bjc/dicelang/ast/optimization/ConstantCollapser.java
@@ -0,0 +1,91 @@
+package bjc.dicelang.ast.optimization;
+
+import bjc.utils.funcdata.IList;
+import bjc.utils.funcdata.ITree;
+import bjc.utils.funcdata.Tree;
+
+import bjc.dicelang.ComplexDice;
+import bjc.dicelang.ast.DiceASTUtils;
+import bjc.dicelang.ast.nodes.IDiceASTNode;
+import bjc.dicelang.ast.nodes.IntegerLiteralNode;
+import bjc.dicelang.ast.nodes.OperatorDiceNode;
+
+/**
+ * Collapses operations with constants to constants
+ * 
+ * @author ben
+ *
+ */
+public class ConstantCollapser implements IOptimizationPass {
+	private static final ArithmeticCollapser	additionCollapser	= new ArithmeticCollapser(
+			(left, right) -> left + right, OperatorDiceNode.ADD);
+
+	private static final ArithmeticCollapser	divideCollapser		= new ArithmeticCollapser(
+			(left, right) -> left / right, OperatorDiceNode.DIVIDE);
+
+	private static final ArithmeticCollapser	multiplyCollapser	= new ArithmeticCollapser(
+			(left, right) -> left * right, OperatorDiceNode.MULTIPLY);
+
+	private static final ArithmeticCollapser	subtractCollapser	= new ArithmeticCollapser(
+			(left, right) -> left - right, OperatorDiceNode.SUBTRACT);
+
+	private static final ArithmeticCollapser	compoundCollapser	= new ArithmeticCollapser(
+			(left, right) -> Integer.parseInt(
+					Integer.toString(left) + Integer.toString(left)),
+			OperatorDiceNode.COMPOUND);
+
+	@Override
+	public ITree<IDiceASTNode> optimizeLeaf(IDiceASTNode leafNode) {
+		// We don't do anything special here
+		return new Tree<>(leafNode);
+	}
+
+	@Override
+	public ITree<IDiceASTNode> optimizeOperator(IDiceASTNode operator,
+			IList<ITree<IDiceASTNode>> children) {
+		if (!operator.isOperator()) {
+			return new Tree<>(operator, children);
+		}
+
+		switch ((OperatorDiceNode) operator) {
+			case ADD:
+				return additionCollapser.collapse(children);
+			case DIVIDE:
+				return divideCollapser.collapse(children);
+			case MULTIPLY:
+				return multiplyCollapser.collapse(children);
+			case SUBTRACT:
+				return subtractCollapser.collapse(children);
+			case COMPOUND:
+				return compoundCollapser.collapse(children);
+			case GROUP:
+				if (children.getSize() != 2) {
+					return new Tree<>(operator, children);
+				}
+
+				ComplexDice dice = new ComplexDice(
+						DiceASTUtils.literalToExpression(
+								children.getByIndex(0)),
+						DiceASTUtils.literalToExpression(
+								children.getByIndex(1)));
+
+				if (dice.canOptimize()) {
+					return new Tree<>(
+							new IntegerLiteralNode(dice.optimize()));
+				}
+
+				return new Tree<>(operator, children);
+			case ARRAY:
+				if (children.getSize() != 1) {
+					return new Tree<>(operator, children);
+				}
+
+				return children.first();
+			case ASSIGN:
+			case LET:
+			default:
+				// We don't optimize these operators
+				return new Tree<>(operator, children);
+		}
+	}
+}