1 files changed, 86 insertions, 0 deletions
diff --git a/dice-lang/src/main/java/bjc/dicelang/ast/optimization/ConstantCollapser.java b/dice-lang/src/main/java/bjc/dicelang/ast/optimization/ConstantCollapser.java
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+++ b/dice-lang/src/main/java/bjc/dicelang/ast/optimization/ConstantCollapser.java
@@ -0,0 +1,86 @@
+package bjc.dicelang.ast.optimization;
+
+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;
+import bjc.utils.funcdata.IFunctionalList;
+import bjc.utils.funcdata.ITree;
+import bjc.utils.funcdata.Tree;
+
+/**
+ * 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.SUBTRACT);
+
+	@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,
+			IFunctionalList<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.toExpression(children.getByIndex(0)),
+						DiceASTUtils.toExpression(children.getByIndex(1)));
+
+				if (dice.canOptimize()) {
+					return new Tree<>(
+							new IntegerLiteralNode(dice.optimize()));
+				}
+
+				return new Tree<>(operator, children);
+			case ASSIGN:
+			default:
+				// We don't optimize these operators
+				return new Tree<>(operator, children);
+		}
+	}
+}