8 files changed, 707 insertions, 0 deletions
diff --git a/dice-lang/src/bjc/utils/dice/ast/DiceASTExpression.java b/dice-lang/src/bjc/utils/dice/ast/DiceASTExpression.java
new file mode 100644
index 0000000..89adb65
--- /dev/null
+++ b/dice-lang/src/bjc/utils/dice/ast/DiceASTExpression.java
@@ -0,0 +1,195 @@
+package bjc.utils.dice.ast;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.BinaryOperator;
+
+import org.apache.commons.lang3.StringUtils;
+
+import bjc.utils.data.Pair;
+import bjc.utils.dice.ComplexDice;
+import bjc.utils.dice.CompoundDice;
+import bjc.utils.dice.IDiceExpression;
+import bjc.utils.parserutils.AST;
+
+/**
+ * An implementation of {@link IDiceExpression} backed by an AST of
+ * {@link IDiceASTNode}s
+ * 
+ * @author ben
+ *
+ */
+public class DiceASTExpression implements IDiceExpression {
+
+	/**
+	 * Build the map of operations to use when collapsing the AST
+	 * 
+	 * @param env
+	 *            The enviroment to evaluate bindings and such against
+	 * @return The operations to use when collapsing the AST
+	 */
+	private static
+			Map<IDiceASTNode, BinaryOperator<Pair<Integer, AST<IDiceASTNode>>>>
+			buildOperations(Map<String, DiceASTExpression> env) {
+		Map<IDiceASTNode, BinaryOperator<Pair<Integer, AST<IDiceASTNode>>>> opCollapsers =
+				new HashMap<>();
+
+		opCollapsers.put(OperatorDiceNode.ADD, (left, right) -> {
+			return left.merge((lval, last) -> right.merge((rval, rast) -> {
+				return new Pair<>(lval + rval,
+						new AST<>(OperatorDiceNode.ADD, last, rast));
+			}));
+
+		});
+		opCollapsers.put(OperatorDiceNode.SUBTRACT, (left, right) -> {
+			return left.merge((lval, last) -> right.merge((rval, rast) -> {
+				return new Pair<>(lval - rval,
+						new AST<>(OperatorDiceNode.SUBTRACT, last, rast));
+			}));
+
+		});
+		opCollapsers.put(OperatorDiceNode.MULTIPLY, (left, right) -> {
+			return left.merge((lval, last) -> right.merge((rval, rast) -> {
+				return new Pair<>(lval * rval,
+						new AST<>(OperatorDiceNode.MULTIPLY, last, rast));
+			}));
+
+		});
+		opCollapsers.put(OperatorDiceNode.DIVIDE, (left, right) -> {
+			return left.merge((lval, last) -> right.merge((rval, rast) -> {
+				return new Pair<>(lval / rval,
+						new AST<>(OperatorDiceNode.DIVIDE, last, rast));
+			}));
+		});
+
+		opCollapsers.put(OperatorDiceNode.ASSIGN, (left, right) -> {
+			return left.merge((lval, last) -> right.merge((rval, rast) -> {
+				String nam = last.collapse((nod) -> {
+					return ((VariableDiceNode) nod).getVariable();
+				} , (v) -> (lv, rv) -> null, (r) -> r);
+
+				env.put(nam, new DiceASTExpression(rast, env));
+
+				return new Pair<>(rval,
+						new AST<>(OperatorDiceNode.ASSIGN, last, rast));
+			}));
+		});
+
+		opCollapsers.put(OperatorDiceNode.COMPOUND, (left, right) -> {
+			return left.merge((lval, last) -> right.merge((rval, rast) -> {
+				int ival = Integer.parseInt(
+						Integer.toString(lval) + Integer.toString(rval));
+
+				return new Pair<>(ival,
+						new AST<>(OperatorDiceNode.COMPOUND, last, rast));
+			}));
+		});
+		opCollapsers.put(OperatorDiceNode.GROUP, (left, right) -> {
+			return left.merge((lval, last) -> right.merge((rval, rast) -> {
+
+				return new Pair<>(new ComplexDice(lval, rval).roll(),
+						new AST<>(OperatorDiceNode.GROUP, last, rast));
+			}));
+		});
+
+		return opCollapsers;
+	}
+
+	/**
+	 * The AST this expression will evaluate
+	 */
+	private AST<IDiceASTNode>				ast;
+
+	/**
+	 * The enviroment to evaluate bindings and such against
+	 */
+	private Map<String, DiceASTExpression>	env;
+
+	/**
+	 * Create a new dice expression backed by an AST
+	 * 
+	 * @param ast
+	 *            The AST backing this expression
+	 * @param env
+	 *            The enviroment to evaluate bindings against
+	 */
+	public DiceASTExpression(AST<IDiceASTNode> ast,
+			Map<String, DiceASTExpression> env) {
+		this.ast = ast;
+		this.env = env;
+	}
+
+	/**
+	 * Expand a leaf AST token into a pair for evaluation
+	 * 
+	 * @param tokn
+	 *            The token to evaluate
+	 * @return A pair consisting of the token's value and the AST it
+	 *         represents
+	 */
+	private Pair<Integer, AST<IDiceASTNode>> evalLeaf(IDiceASTNode tokn) {
+		if (tokn instanceof VariableDiceNode) {
+			String varName = ((VariableDiceNode) tokn).getVariable();
+
+			if (env.containsKey(varName)) {
+				return new Pair<>(env.get(varName).roll(),
+						new AST<>(tokn));
+			} else {
+				// Handle special case for defining variables
+				return new Pair<>(0, new AST<>(tokn));
+			}
+		} else {
+			LiteralDiceNode lnod = (LiteralDiceNode) tokn;
+			String dat = lnod.getData();
+
+			if (StringUtils.countMatches(dat, 'c') == 1
+					&& !dat.equalsIgnoreCase("c")) {
+				String[] strangs = dat.split("c");
+				return new Pair<>(new CompoundDice(strangs).roll(),
+						new AST<>(tokn));
+			} else if (StringUtils.countMatches(dat, 'd') == 1
+					&& !dat.equalsIgnoreCase("d")) {
+				/*
+				 * Handle dice groups
+				 */
+				return new Pair<>(ComplexDice.fromString(dat).roll(),
+						new AST<>(tokn));
+			} else {
+				return new Pair<>(Integer.parseInt(dat), new AST<>(tokn));
+			}
+		}
+	}
+
+	/**
+	 * Get the AST bound to this expression
+	 * 
+	 * @return the ast
+	 */
+	public AST<IDiceASTNode> getAst() {
+		return ast;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see bjc.utils.dice.IDiceExpression#roll()
+	 */
+	@Override
+	public int roll() {
+		Map<IDiceASTNode, BinaryOperator<Pair<Integer, AST<IDiceASTNode>>>> operations =
+				buildOperations(env);
+
+		return ast.collapse(this::evalLeaf, operations::get,
+				(r) -> r.merge((left, right) -> left));
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see java.lang.Object#toString()
+	 */
+	@Override
+	public String toString() {
+		return ast.toString();
+	}
+}
diff --git a/dice-lang/src/bjc/utils/dice/ast/DiceASTFlattener.java b/dice-lang/src/bjc/utils/dice/ast/DiceASTFlattener.java
new file mode 100644
index 0000000..70465a5
--- /dev/null
+++ b/dice-lang/src/bjc/utils/dice/ast/DiceASTFlattener.java
@@ -0,0 +1,114 @@
+package bjc.utils.dice.ast;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.BinaryOperator;
+
+import org.apache.commons.lang3.StringUtils;
+
+import bjc.utils.dice.BindingDiceExpression;
+import bjc.utils.dice.ComplexDice;
+import bjc.utils.dice.CompoundDice;
+import bjc.utils.dice.CompoundDiceExpression;
+import bjc.utils.dice.DiceExpressionType;
+import bjc.utils.dice.IDiceExpression;
+import bjc.utils.dice.ReferenceDiceExpression;
+import bjc.utils.dice.ScalarDie;
+import bjc.utils.parserutils.AST;
+
+/**
+ * Flatten an {@link AST} of {@link IDiceASTNode} into a
+ * {@link IDiceExpression}
+ * 
+ * @author ben
+ *
+ */
+public class DiceASTFlattener {
+	/**
+	 * Build the operations to use for tree flattening
+	 * 
+	 * @param env
+	 *            The enviroment the tree will be flattened against
+	 * @return The operations needed for tree flattening
+	 */
+	private static Map<IDiceASTNode, BinaryOperator<IDiceExpression>>
+			buildOperations(Map<String, IDiceExpression> env) {
+		Map<IDiceASTNode, BinaryOperator<IDiceExpression>> opCollapsers =
+				new HashMap<>();
+		opCollapsers.put(OperatorDiceNode.ADD, (left, right) -> {
+			return new CompoundDiceExpression(right, left,
+					DiceExpressionType.ADD);
+		});
+		opCollapsers.put(OperatorDiceNode.SUBTRACT, (left, right) -> {
+			return new CompoundDiceExpression(right, left,
+					DiceExpressionType.SUBTRACT);
+		});
+		opCollapsers.put(OperatorDiceNode.MULTIPLY, (left, right) -> {
+			return new CompoundDiceExpression(right, left,
+					DiceExpressionType.MULTIPLY);
+		});
+		opCollapsers.put(OperatorDiceNode.DIVIDE, (left, right) -> {
+			return new CompoundDiceExpression(right, left,
+					DiceExpressionType.DIVIDE);
+		});
+		opCollapsers.put(OperatorDiceNode.ASSIGN, (left, right) -> {
+			return new BindingDiceExpression(left, right, env);
+		});
+		opCollapsers.put(OperatorDiceNode.COMPOUND, (left, right) -> {
+			return new CompoundDice(left, right);
+		});
+		opCollapsers.put(OperatorDiceNode.GROUP, (left, right) -> {
+			return new ComplexDice(left, right);
+		});
+
+		return opCollapsers;
+	}
+
+	/**
+	 * Create a dice expression from a literal token
+	 * 
+	 * @param tok
+	 *            The token to convert to an expression
+	 * @return The dice expression represented by the token
+	 */
+	private static IDiceExpression expFromLiteral(LiteralDiceNode tok) {
+		String data = tok.getData();
+
+		if (StringUtils.countMatches(data, 'c') == 1
+				&& !data.equalsIgnoreCase("c")) {
+			String[] strangs = data.split("c");
+
+			return new CompoundDice(ComplexDice.fromString(strangs[0]),
+					ComplexDice.fromString(strangs[1]));
+		} else if (StringUtils.countMatches(data, 'd') == 1
+				&& !data.equalsIgnoreCase("d")) {
+			return ComplexDice.fromString(data);
+		} else {
+			return new ScalarDie(Integer.parseInt(data));
+		}
+	}
+
+	/**
+	 * Flatten a AST into a dice expression
+	 * 
+	 * @param ast
+	 *            The AST to flatten
+	 * @param env
+	 *            The enviroment to flatten against
+	 * @return The AST, flattened into a dice expression
+	 */
+	public static IDiceExpression flatten(AST<IDiceASTNode> ast,
+			Map<String, IDiceExpression> env) {
+		Map<IDiceASTNode, BinaryOperator<IDiceExpression>> opCollapsers =
+				buildOperations(env);
+
+		return ast.collapse((nod) -> {
+			if (nod instanceof LiteralDiceNode) {
+				return expFromLiteral((LiteralDiceNode) nod);
+			} else {
+				return new ReferenceDiceExpression(
+						((VariableDiceNode) nod).getVariable(), env);
+			}
+		} , opCollapsers::get, (r) -> r);
+	}
+}
diff --git a/dice-lang/src/bjc/utils/dice/ast/DiceASTFreezer.java b/dice-lang/src/bjc/utils/dice/ast/DiceASTFreezer.java
new file mode 100644
index 0000000..efe37c0
--- /dev/null
+++ b/dice-lang/src/bjc/utils/dice/ast/DiceASTFreezer.java
@@ -0,0 +1,92 @@
+package bjc.utils.dice.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);
+	}
+}
diff --git a/dice-lang/src/bjc/utils/dice/ast/DiceASTParser.java b/dice-lang/src/bjc/utils/dice/ast/DiceASTParser.java
new file mode 100644
index 0000000..38c514a
--- /dev/null
+++ b/dice-lang/src/bjc/utils/dice/ast/DiceASTParser.java
@@ -0,0 +1,108 @@
+package bjc.utils.dice.ast;
+
+import org.apache.commons.lang3.StringUtils;
+
+import bjc.utils.funcdata.FunctionalList;
+import bjc.utils.funcdata.FunctionalStringTokenizer;
+import bjc.utils.parserutils.AST;
+import bjc.utils.parserutils.ShuntingYard;
+import bjc.utils.parserutils.TreeConstructor;
+
+/**
+ * Create an AST from a string expression
+ * 
+ * @author ben
+ *
+ */
+public class DiceASTParser {
+	/**
+	 * The yard to use for shunting expressions
+	 */
+	private static ShuntingYard<String> yard;
+
+	static {
+		yard = new ShuntingYard<>();
+
+		yard.addOp("d", 5); // dice operator: use for creating variable
+		// size dice groups
+		yard.addOp("c", 6); // compound operator: use for creating compound
+		// dice from expressions
+		yard.addOp(":=", 0); // binding operator: Bind a name to a variable
+		// expression
+	}
+
+	/**
+	 * Build an AST from a string expression
+	 * 
+	 * @param exp
+	 *            The string to build from
+	 * @return An AST built from the passed in string
+	 */
+	public AST<IDiceASTNode> buildAST(String exp) {
+		FunctionalList<String> tokens = FunctionalStringTokenizer
+				.fromString(exp).toList((s) -> s);
+
+		FunctionalList<String> shunted = yard.postfix(tokens, (s) -> s);
+
+		AST<String> rawAST = TreeConstructor.constructTree(shunted,
+				this::isOperator, (op) -> false, null);
+
+		AST<IDiceASTNode> bakedAST = rawAST.transmuteAST((tok) -> {
+			if (isOperator(tok)) {
+				return OperatorDiceNode.fromString(tok);
+			} else if (isLiteral(tok)) {
+				return new LiteralDiceNode(tok);
+			} else {
+				return new VariableDiceNode(tok);
+			}
+		});
+
+		return bakedAST;
+	}
+
+	/**
+	 * Check if a token represents a literal
+	 * 
+	 * @param tok
+	 *            The token to check
+	 * @return Whether or not the token represents a literal
+	 */
+	private static boolean isLiteral(String tok) {
+		if (StringUtils.countMatches(tok, 'c') == 1
+				&& !tok.equalsIgnoreCase("c")) {
+			return true;
+		} else if (StringUtils.countMatches(tok, 'd') == 1
+				&& !tok.equalsIgnoreCase("d")) {
+			return true;
+		} else {
+			try {
+				Integer.parseInt(tok);
+				return true;
+			} catch (NumberFormatException nfx) {
+				return false;
+			}
+		}
+	}
+
+	/**
+	 * Check if a token represents an operator
+	 * 
+	 * @param tok
+	 *            The token to check if it represents an operator
+	 * @return Whether or not the token represents an operator
+	 */
+	private boolean isOperator(String tok) {
+		switch (tok) {
+			case ":=":
+			case "+":
+			case "-":
+			case "*":
+			case "/":
+			case "c":
+			case "d":
+				return true;
+			default:
+				return false;
+		}
+	}
+}
diff --git a/dice-lang/src/bjc/utils/dice/ast/IDiceASTNode.java b/dice-lang/src/bjc/utils/dice/ast/IDiceASTNode.java
new file mode 100644
index 0000000..073da89
--- /dev/null
+++ b/dice-lang/src/bjc/utils/dice/ast/IDiceASTNode.java
@@ -0,0 +1,16 @@
+package bjc.utils.dice.ast;
+
+/**
+ * The interface for a node in a dice AST
+ * 
+ * @author ben
+ *
+ */
+public interface IDiceASTNode {
+	/**
+	 * Check if this node represents an operator or not
+	 * 
+	 * @return Whether or not this node represents an operator
+	 */
+	public boolean isOperator();
+}
diff --git a/dice-lang/src/bjc/utils/dice/ast/LiteralDiceNode.java b/dice-lang/src/bjc/utils/dice/ast/LiteralDiceNode.java
new file mode 100644
index 0000000..b0c1400
--- /dev/null
+++ b/dice-lang/src/bjc/utils/dice/ast/LiteralDiceNode.java
@@ -0,0 +1,48 @@
+package bjc.utils.dice.ast;
+
+/**
+ * A AST node that represents a literal value
+ * 
+ * @author ben
+ *
+ */
+public class LiteralDiceNode implements IDiceASTNode {
+	/**
+	 * The value contained by this node
+	 */
+	private String data;
+
+	/**
+	 * Create a new node with the given value
+	 * 
+	 * @param data
+	 *            The value to be in this node
+	 */
+	public LiteralDiceNode(String data) {
+		this.data = data;
+	}
+
+	@Override
+	public boolean isOperator() {
+		return false;
+	}
+
+	/**
+	 * Get the data stored in this AST node
+	 * 
+	 * @return the data stored in this AST node
+	 */
+	public String getData() {
+		return data;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see java.lang.Object#toString()
+	 */
+	@Override
+	public String toString() {
+		return data;
+	}
+}
diff --git a/dice-lang/src/bjc/utils/dice/ast/OperatorDiceNode.java b/dice-lang/src/bjc/utils/dice/ast/OperatorDiceNode.java
new file mode 100644
index 0000000..c4f7763
--- /dev/null
+++ b/dice-lang/src/bjc/utils/dice/ast/OperatorDiceNode.java
@@ -0,0 +1,81 @@
+package bjc.utils.dice.ast;
+
+// The following classes need to be changed upon addition of a new operator
+// 1. DiceASTExpression
+// 2. DiceASTFlattener
+// 3. DiceASTParser
+/**
+ * A node that represents an operator
+ * 
+ * @author ben
+ *
+ */
+public enum OperatorDiceNode implements IDiceASTNode {
+	/**
+	 * Represents adding two nodes
+	 */
+	ADD,
+	/**
+	 * Represents assigning one node to another
+	 */
+	ASSIGN,
+	/**
+	 * Representings combining two node values together
+	 */
+	COMPOUND,
+	/**
+	 * Represents dividing two nodes
+	 */
+	DIVIDE,
+	/**
+	 * Represents using one node a variable number of times
+	 */
+	GROUP,
+	/**
+	 * Represents multiplying two nodes
+	 */
+	MULTIPLY,
+	/**
+	 * Represents subtracting two nodes
+	 */
+	SUBTRACT;
+
+	/**
+	 * Create a operator node from a string
+	 * 
+	 * @param s
+	 *            The string to convert to a node
+	 * @return The operator corresponding to the node
+	 */
+	public static OperatorDiceNode fromString(String s) {
+		switch (s) {
+			case ":=":
+				return ASSIGN;
+			case "+":
+				return ADD;
+			case "-":
+				return SUBTRACT;
+			case "*":
+				return MULTIPLY;
+			case "/":
+				return DIVIDE;
+			case "d":
+				return GROUP;
+			case "c":
+				return COMPOUND;
+			default:
+				throw new IllegalArgumentException(
+						s + " is not a valid operator node");
+		}
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see bjc.utils.dice.ast.IDiceASTNode#isOperator()
+	 */
+	@Override
+	public boolean isOperator() {
+		return true;
+	}
+}
diff --git a/dice-lang/src/bjc/utils/dice/ast/VariableDiceNode.java b/dice-lang/src/bjc/utils/dice/ast/VariableDiceNode.java
new file mode 100644
index 0000000..43a09b2
--- /dev/null
+++ b/dice-lang/src/bjc/utils/dice/ast/VariableDiceNode.java
@@ -0,0 +1,53 @@
+package bjc.utils.dice.ast;
+
+/**
+ * A node that represents a variable reference
+ * 
+ * @author ben
+ *
+ */
+public class VariableDiceNode implements IDiceASTNode {
+	/**
+	 * The variable referenced by this node
+	 */
+	private String var;
+
+	/**
+	 * Create a new node representing the specified variable
+	 * 
+	 * @param data
+	 *            The name of the variable being referenced
+	 */
+	public VariableDiceNode(String data) {
+		this.var = data;
+	}
+
+	/**
+	 * Get the variable referenced by this AST node
+	 * 
+	 * @return the variable referenced by this AST node
+	 */
+	public String getVariable() {
+		return var;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see bjc.utils.dice.ast.IDiceASTNode#isOperator()
+	 */
+	@Override
+	public boolean isOperator() {
+		return false;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see java.lang.Object#toString()
+	 */
+	@Override
+	public String toString() {
+		return var;
+	}
+}