Code maintenance and changes

4 files changed, 185 insertions, 148 deletions

diff --git a/dice-lang/src/main/java/bjc/dicelang/ast/ArithmeticCollapser.java b/dice-lang/src/main/java/bjc/dicelang/ast/ArithmeticCollapser.java
new file mode 100644
index 0000000..5ad0a0f
--- /dev/null
+++ b/dice-lang/src/main/java/bjc/dicelang/ast/ArithmeticCollapser.java
@@ -0,0 +1,64 @@
+package bjc.dicelang.ast;
+
+import java.util.function.BinaryOperator;
+
+import bjc.dicelang.ast.nodes.IDiceASTNode;
+import bjc.dicelang.ast.nodes.OperatorDiceNode;
+import bjc.utils.data.IPair;
+import bjc.utils.data.Pair;
+import bjc.utils.funcdata.IFunctionalList;
+import bjc.utils.funcdata.ITree;
+import bjc.utils.funcdata.Tree;
+
+/**
+ * Responsible for collapsing arithmetic operators
+ * 
+ * @author ben
+ *
+ */
+final class ArithmeticCollapser
+		implements IOperatorCollapser {
+	private OperatorDiceNode		type;
+
+	private BinaryOperator<Integer>	valueOp;
+
+	public ArithmeticCollapser(OperatorDiceNode type,
+			BinaryOperator<Integer> valueOp) {
+		this.type = type;
+		this.valueOp = valueOp;
+	}
+
+	@Override
+	public IPair<Integer, ITree<IDiceASTNode>> apply(
+			IFunctionalList<IPair<Integer, ITree<IDiceASTNode>>> nodes) {
+		IPair<Integer, ITree<IDiceASTNode>> initState =
+				new Pair<>(0, new Tree<>(type));
+
+		BinaryOperator<IPair<Integer, ITree<IDiceASTNode>>> reducer =
+				(accumulatedState, currentState) -> {
+					return reduceStates(accumulatedState,
+							currentState);
+				};
+
+		return nodes.reduceAux(initState, reducer, (state) -> state);
+	}
+
+	private IPair<Integer, ITree<IDiceASTNode>> reduceStates(
+			IPair<Integer, ITree<IDiceASTNode>> accumulatedState,
+			IPair<Integer, ITree<IDiceASTNode>> currentState) {
+		return accumulatedState
+				.bind((accumulatedValue, accumulatedTree) -> {
+					return currentState
+							.bind((currentValue, currentTree) -> {
+								accumulatedTree.addChild(currentTree);
+
+								Integer combinedValue =
+										valueOp.apply(accumulatedValue,
+												currentValue);
+
+								return new Pair<>(combinedValue,
+										accumulatedTree);
+							});
+				});
+	}
+}
\ No newline at end of file
diff --git a/dice-lang/src/main/java/bjc/dicelang/ast/DiceASTEvaluator.java b/dice-lang/src/main/java/bjc/dicelang/ast/DiceASTEvaluator.java
index 454850c..e934b9f 100644
--- a/dice-lang/src/main/java/bjc/dicelang/ast/DiceASTEvaluator.java
+++ b/dice-lang/src/main/java/bjc/dicelang/ast/DiceASTEvaluator.java
@@ -1,9 +1,6 @@
 package bjc.dicelang.ast;
 
-import java.util.function.BinaryOperator;
-
 import bjc.dicelang.ComplexDice;
-
 import bjc.dicelang.ast.nodes.DiceASTType;
 import bjc.dicelang.ast.nodes.DiceLiteralNode;
 import bjc.dicelang.ast.nodes.DiceLiteralType;
@@ -12,15 +9,14 @@ import bjc.dicelang.ast.nodes.ILiteralDiceNode;
 import bjc.dicelang.ast.nodes.IntegerLiteralNode;
 import bjc.dicelang.ast.nodes.OperatorDiceNode;
 import bjc.dicelang.ast.nodes.VariableDiceNode;
-
-import bjc.utils.data.GenHolder;
 import bjc.utils.data.IPair;
+import bjc.utils.data.LazyPair;
 import bjc.utils.data.Pair;
-import bjc.utils.data.lazy.LazyPair;
 import bjc.utils.funcdata.FunctionalMap;
+import bjc.utils.funcdata.IFunctionalList;
 import bjc.utils.funcdata.IFunctionalMap;
-import bjc.utils.funcdata.bst.ITreePart.TreeLinearizationMethod;
-import bjc.utils.parserutils.AST;
+import bjc.utils.funcdata.ITree;
+import bjc.utils.funcdata.Tree;
 
 /**
  * Evaluate a dice AST to an integer value
@@ -30,53 +26,17 @@ import bjc.utils.parserutils.AST;
  */
 public class DiceASTEvaluator {
 	/**
-	 * Responsible for collapsing arithmetic operators
-	 * 
-	 * @author ben
-	 *
-	 */
-	private static final class ArithmeticCollapser
-			implements IOperatorCollapser {
-		private OperatorDiceNode		type;
-
-		private BinaryOperator<Integer>	valueOp;
-
-		public ArithmeticCollapser(OperatorDiceNode type,
-				BinaryOperator<Integer> valueOp) {
-			this.type = type;
-			this.valueOp = valueOp;
-		}
-
-		@Override
-		public IPair<Integer, AST<IDiceASTNode>> apply(
-				IPair<Integer, AST<IDiceASTNode>> leftNode,
-				IPair<Integer, AST<IDiceASTNode>> rightNode) {
-			return leftNode.bind((leftValue, leftAST) -> {
-				return rightNode.bind((rightValue, rightAST) -> {
-					if (type == OperatorDiceNode.DIVIDE
-							&& rightValue == 0) {
-						throw new ArithmeticException(
-								"Attempted to divide by zero. The AST of the problem expression is "
-										+ rightAST);
-					}
-
-					return new Pair<>(valueOp.apply(leftValue, rightValue),
-							new AST<>(type, leftAST, rightAST));
-				});
-			});
-		}
-	}
-
-	/**
 	 * Build the map of operations to use when collapsing the AST
 	 * 
 	 * @param enviroment
 	 *            The enviroment to evaluate bindings and such against
 	 * @return The operations to use when collapsing the AST
 	 */
-	private static IFunctionalMap<IDiceASTNode, IOperatorCollapser> buildOperations(
-			IFunctionalMap<String, AST<IDiceASTNode>> enviroment) {
-		IFunctionalMap<IDiceASTNode, IOperatorCollapser> operatorCollapsers = new FunctionalMap<>();
+	private static IFunctionalMap<IDiceASTNode, IOperatorCollapser>
+			buildOperations(
+					IFunctionalMap<String, ITree<IDiceASTNode>> enviroment) {
+		IFunctionalMap<IDiceASTNode, IOperatorCollapser> operatorCollapsers =
+				new FunctionalMap<>();
 
 		operatorCollapsers.put(OperatorDiceNode.ADD,
 				new ArithmeticCollapser(OperatorDiceNode.ADD,
@@ -94,8 +54,8 @@ public class DiceASTEvaluator {
 				new ArithmeticCollapser(OperatorDiceNode.DIVIDE,
 						(left, right) -> left / right));
 
-		operatorCollapsers.put(OperatorDiceNode.ASSIGN, (left, right) -> {
-			return parseBinding(enviroment, left, right);
+		operatorCollapsers.put(OperatorDiceNode.ASSIGN, (nodes) -> {
+			return parseBinding(enviroment, nodes);
 		});
 
 		operatorCollapsers.put(OperatorDiceNode.COMPOUND,
@@ -116,38 +76,30 @@ public class DiceASTEvaluator {
 	 *            The enviroment to look up variables in
 	 * @return The integer value of the expression
 	 */
-	public static int evaluateAST(AST<IDiceASTNode> expression,
-			IFunctionalMap<String, AST<IDiceASTNode>> enviroment) {
-		IFunctionalMap<IDiceASTNode, IOperatorCollapser> collapsers = buildOperations(
-				enviroment);
+	public static int evaluateAST(ITree<IDiceASTNode> expression,
+			IFunctionalMap<String, ITree<IDiceASTNode>> enviroment) {
+		IFunctionalMap<IDiceASTNode, IOperatorCollapser> collapsers =
+				buildOperations(enviroment);
 
 		return expression.collapse(
 				(node) -> evaluateLeaf(node, enviroment), collapsers::get,
-				(pair) -> pair.merge((left, right) -> left));
+				(pair) -> pair.getLeft());
 	}
 
-	private static IPair<Integer, AST<IDiceASTNode>> evaluateLeaf(
+	private static IPair<Integer, ITree<IDiceASTNode>> evaluateLeaf(
 			IDiceASTNode leafNode,
-			IFunctionalMap<String, AST<IDiceASTNode>> enviroment) {
-		AST<IDiceASTNode> returnedAST = new AST<>(leafNode);
+			IFunctionalMap<String, ITree<IDiceASTNode>> enviroment) {
+		ITree<IDiceASTNode> returnedAST = new Tree<>(leafNode);
 
 		switch (leafNode.getType()) {
 			case LITERAL:
-
 				return new Pair<>(evaluateLiteral(leafNode), returnedAST);
+
 			case VARIABLE:
 				return new LazyPair<>(() -> {
-					String variableName = ((VariableDiceNode) leafNode)
-							.getVariable();
-
-					if (enviroment.containsKey(variableName)) {
-						return evaluateAST(enviroment.get(variableName),
-								enviroment);
-					}
-
-					// Value to allow for assignments
-					return 0;
+					return bindLiteralValue(leafNode, enviroment);
 				}, () -> returnedAST);
+
 			case OPERATOR:
 			default:
 				throw new UnsupportedOperationException(
@@ -155,9 +107,21 @@ public class DiceASTEvaluator {
 		}
 	}
 
+	private static Integer bindLiteralValue(IDiceASTNode leafNode,
+			IFunctionalMap<String, ITree<IDiceASTNode>> enviroment) {
+		String variableName = ((VariableDiceNode) leafNode).getVariable();
+
+		if (enviroment.containsKey(variableName)) {
+			return evaluateAST(enviroment.get(variableName), enviroment);
+		}
+
+		// Value to allow for assignments
+		return 0;
+	}
+
 	private static int evaluateLiteral(IDiceASTNode leafNode) {
-		DiceLiteralType literalType = ((ILiteralDiceNode) leafNode)
-				.getLiteralType();
+		DiceLiteralType literalType =
+				((ILiteralDiceNode) leafNode).getLiteralType();
 
 		switch (literalType) {
 			case DICE:
@@ -171,88 +135,95 @@ public class DiceASTEvaluator {
 		}
 	}
 
-	private static IPair<Integer, AST<IDiceASTNode>> parseBinding(
-			IFunctionalMap<String, AST<IDiceASTNode>> enviroment,
-			IPair<Integer, AST<IDiceASTNode>> left,
-			IPair<Integer, AST<IDiceASTNode>> right) {
-		return left.bind((leftValue, leftAST) -> {
-			return right.bind((rightValue, rightAST) -> {
-				String variableName = leftAST.applyToHead((node) -> {
-					if (node.getType() != DiceASTType.VARIABLE) {
-						throw new UnsupportedOperationException(
-								"Attempted to assign to '" + node
-										+ "' which is not a variable");
-					}
-
-					return ((VariableDiceNode) node).getVariable();
-				});
-
-				GenHolder<Boolean> selfReference = new GenHolder<>(false);
-
-				DiceASTReferenceChecker refChecker = new DiceASTReferenceChecker(
-						selfReference, variableName);
-
-				rightAST.traverse(TreeLinearizationMethod.PREORDER,
-						refChecker);
-
-				// Ignore meta-variable
-				if (selfReference.unwrap((bool) -> bool)
-						&& !variableName.equals("last")) {
-					throw new UnsupportedOperationException(
-							"Variable '" + variableName
-									+ "' references itself. Problematic definition: \n\t"
-									+ rightAST);
-				}
+	private static IPair<Integer, ITree<IDiceASTNode>> parseBinding(
+			IFunctionalMap<String, ITree<IDiceASTNode>> enviroment,
+			IFunctionalList<IPair<Integer, ITree<IDiceASTNode>>> nodes) {
+		if (nodes.getSize() != 2) {
+			throw new UnsupportedOperationException(
+					"Can only bind nodes with two children. Problem children are "
+							+ nodes);
+		}
 
-				if (!variableName.equals("last")) {
-					enviroment.put(variableName, rightAST);
-				} else {
-					// Do nothing, last is an auto-handled meta-variable
+		IPair<Integer, ITree<IDiceASTNode>> nameNode = nodes.getByIndex(0);
+		IPair<Integer, ITree<IDiceASTNode>> valueNode =
+				nodes.getByIndex(1);
+
+		return nameNode.bindRight((nameTree) -> {
+			return valueNode.bind((valueValue, valueTree) -> {
+				if (containsSimpleVariable(nameTree)) {
+					String varName = nameTree.transformHead((nameNod) -> {
+						return ((VariableDiceNode) nameNod).getVariable();
+					});
+
+					enviroment.put(varName, valueTree);
+
+					return new Pair<>(valueValue, nameTree);
 				}
 
-				return new Pair<>(rightValue, new AST<>(
-						OperatorDiceNode.ASSIGN, leftAST, rightAST));
+				throw new IllegalStateException(
+						"Statement that shouldn't be hit was hit.");
 			});
 		});
 	}
 
-	private static IPair<Integer, AST<IDiceASTNode>> parseCompound(
-			IPair<Integer, AST<IDiceASTNode>> leftNode,
-			IPair<Integer, AST<IDiceASTNode>> rightNode) {
-		return leftNode.bind((leftValue, leftAST) -> {
-			return rightNode.bind((rightValue, rightAST) -> {
-				int compoundValue = Integer
-						.parseInt(Integer.toString(leftValue)
-								+ Integer.toString(rightValue));
-
-				return new Pair<>(compoundValue, new AST<>(
-						OperatorDiceNode.COMPOUND, leftAST, rightAST));
+	private static boolean
+			containsSimpleVariable(ITree<IDiceASTNode> nameTree) {
+		return nameTree.transformHead((nameNod) -> {
+			if (nameNod.getType() != DiceASTType.VARIABLE) {
+				throw new UnsupportedOperationException(
+						"Assigning to complex variables isn't supported. Problem node is "
+								+ nameNod);
+			}
+
+			return true;
+		});
+	}
+
+	private static IPair<Integer, ITree<IDiceASTNode>> parseCompound(
+			IFunctionalList<IPair<Integer, ITree<IDiceASTNode>>> nodes) {
+		if (nodes.getSize() != 2) {
+			throw new UnsupportedOperationException(
+					"Can only form a group from two dice");
+		}
+
+		IPair<Integer, ITree<IDiceASTNode>> leftDiceNode =
+				nodes.getByIndex(0);
+		IPair<Integer, ITree<IDiceASTNode>> rightDiceNode =
+				nodes.getByIndex(1);
+
+		return leftDiceNode.bind((leftDiceValue, leftDiceTree) -> {
+			return rightDiceNode.bind((rightDiceValue, rightDiceTree) -> {
+				Integer result =
+						Integer.parseInt(Integer.toString(leftDiceValue)
+								+ Integer.toString(rightDiceValue));
+
+				return new Pair<>(result,
+						new Tree<>(OperatorDiceNode.GROUP, leftDiceTree,
+								rightDiceTree));
 			});
 		});
 	}
 
-	private static IPair<Integer, AST<IDiceASTNode>> parseGroup(
-			IPair<Integer, AST<IDiceASTNode>> leftNode,
-			IPair<Integer, AST<IDiceASTNode>> rightNode) {
-		return leftNode.bind((leftValue, leftAST) -> {
-			return rightNode.bind((rightValue, rightAST) -> {
-				if (leftValue < 0) {
-					throw new UnsupportedOperationException(
-							"Can't attempt to roll a negative number of dice."
-									+ " The problematic AST is "
-									+ leftAST);
-				} else if (rightValue < 1) {
-					throw new UnsupportedOperationException(
-							"Can't roll dice with less than one side."
-									+ " The problematic AST is "
-									+ rightAST);
-				}
+	private static IPair<Integer, ITree<IDiceASTNode>> parseGroup(
+			IFunctionalList<IPair<Integer, ITree<IDiceASTNode>>> nodes) {
+		if (nodes.getSize() != 2) {
+			throw new UnsupportedOperationException(
+					"Can only form a group from two dice");
+		}
+
+		IPair<Integer, ITree<IDiceASTNode>> numberDiceNode =
+				nodes.getByIndex(0);
+		IPair<Integer, ITree<IDiceASTNode>> diceTypeNode =
+				nodes.getByIndex(1);
 
-				int rolledValue = new ComplexDice(leftValue, rightValue)
-						.roll();
+		return numberDiceNode.bind((numberDiceValue, numberDiceTree) -> {
+			return diceTypeNode.bind((diceTypeValue, diceTypeTree) -> {
+				ComplexDice cDice =
+						new ComplexDice(numberDiceValue, diceTypeValue);
 
-				return new Pair<>(rolledValue, new AST<>(
-						OperatorDiceNode.GROUP, leftAST, rightAST));
+				return new Pair<>(cDice.roll(),
+						new Tree<>(OperatorDiceNode.GROUP, numberDiceTree,
+								diceTypeTree));
 			});
 		});
 	}
diff --git a/dice-lang/src/main/java/bjc/dicelang/ast/DiceASTParser.java b/dice-lang/src/main/java/bjc/dicelang/ast/DiceASTParser.java
index f6500e3..95495bd 100644
--- a/dice-lang/src/main/java/bjc/dicelang/ast/DiceASTParser.java
+++ b/dice-lang/src/main/java/bjc/dicelang/ast/DiceASTParser.java
@@ -11,7 +11,7 @@ import bjc.dicelang.ast.nodes.IntegerLiteralNode;
 import bjc.dicelang.ast.nodes.OperatorDiceNode;
 import bjc.dicelang.ast.nodes.VariableDiceNode;
 import bjc.utils.funcdata.IFunctionalList;
-import bjc.utils.parserutils.AST;
+import bjc.utils.funcdata.ITree;
 import bjc.utils.parserutils.TreeConstructor;
 
 /**
@@ -28,9 +28,9 @@ public class DiceASTParser {
 	 *            The list of tokens to convert
 	 * @return An AST built from the tokens
 	 */
-	public static AST<IDiceASTNode> createFromString(
+	public static ITree<IDiceASTNode> createFromString(
 			IFunctionalList<String> tokens) {
-		AST<String> rawTokens = TreeConstructor.constructTree(tokens,
+		ITree<String> rawTokens = TreeConstructor.constructTree(tokens,
 				(token) -> {
 					return isOperatorNode(token);
 				}, (operator) -> false, null);
diff --git a/dice-lang/src/main/java/bjc/dicelang/ast/IOperatorCollapser.java b/dice-lang/src/main/java/bjc/dicelang/ast/IOperatorCollapser.java
index ed818d4..10df77b 100644
--- a/dice-lang/src/main/java/bjc/dicelang/ast/IOperatorCollapser.java
+++ b/dice-lang/src/main/java/bjc/dicelang/ast/IOperatorCollapser.java
@@ -1,10 +1,11 @@
 package bjc.dicelang.ast;
 
-import java.util.function.BinaryOperator;
+import java.util.function.Function;
 
 import bjc.dicelang.ast.nodes.IDiceASTNode;
 import bjc.utils.data.IPair;
-import bjc.utils.parserutils.AST;
+import bjc.utils.funcdata.IFunctionalList;
+import bjc.utils.funcdata.ITree;
 
 /**
  * Alias for operator collapsers. Because 68-char types are too long
@@ -12,7 +13,8 @@ import bjc.utils.parserutils.AST;
  * @author ben
  *
  */
-public interface IOperatorCollapser
-		extends BinaryOperator<IPair<Integer, AST<IDiceASTNode>>> {
+public interface IOperatorCollapser extends
+		Function<IFunctionalList<IPair<Integer, ITree<IDiceASTNode>>>,
+							IPair<Integer, ITree<IDiceASTNode>>> {
 	// Just an alias
 }