From 77a797089a2e065cc8cf2a83ae8356b16591aebe Mon Sep 17 00:00:00 2001
From: bculkin2442 <bjculkin@mix.wvu.edu>
Date: Sun, 21 Feb 2016 15:40:30 -0500
Subject: Revamping of the way dice work

---
 .../java/bjc/utils/dice/DiceExpressionParser.java  | 80 ++++++++++++++++++++--
 1 file changed, 73 insertions(+), 7 deletions(-)

(limited to 'BJC-Utils2/src/main/java/bjc/utils/dice/DiceExpressionParser.java')

diff --git a/BJC-Utils2/src/main/java/bjc/utils/dice/DiceExpressionParser.java b/BJC-Utils2/src/main/java/bjc/utils/dice/DiceExpressionParser.java
index 3be56e4..71801f8 100644
--- a/BJC-Utils2/src/main/java/bjc/utils/dice/DiceExpressionParser.java
+++ b/BJC-Utils2/src/main/java/bjc/utils/dice/DiceExpressionParser.java
@@ -6,27 +6,80 @@ import bjc.utils.funcdata.FunctionalList;
 import bjc.utils.funcdata.FunctionalStringTokenizer;
 import bjc.utils.parserutils.ShuntingYard;
 
+/**
+ * Parse a dice expression from a string
+ * 
+ * @author ben
+ *
+ */
 public class DiceExpressionParser {
-	public DiceExpression parse(String exp) {
+	/**
+	 * Parse a dice expression from a string
+	 * 
+	 * @param exp
+	 *            The string to parse an expression from
+	 * @return The parsed dice expression
+	 */
+	public IDiceExpression parse(String exp) {
+		/*
+		 * Create a tokenizer over the strings
+		 */
 		FunctionalStringTokenizer fst = new FunctionalStringTokenizer(exp);
 
+		/*
+		 * Create a shunter to rewrite the expression
+		 */
 		ShuntingYard<String> yard = new ShuntingYard<>();
 
+		/*
+		 * Add our custom operators to the yard
+		 */
+		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
+
+		/*
+		 * Shunt the expression to postfix form
+		 */
 		FunctionalList<String> ls = yard.postfix(fst.toList(s -> s),
 				s -> s);
 
-		Stack<DiceExpression> dexps = new Stack<>();
+		/*
+		 * Create a stack for building an expression from parts
+		 */
+		Stack<IDiceExpression> dexps = new Stack<>();
 
+		/*
+		 * Create the expression from parts
+		 */
 		ls.forEach((tok) -> {
-			if (tok.contains("d")) {
-				dexps.push(Dice.fromString(tok));
+			/*
+			 * Handle compound dice
+			 */
+			if (tok.contains("c") && !tok.equalsIgnoreCase("c")) {
+				String[] strangs = tok.split("c");
+
+				dexps.push(new CompoundDice(LazyDice.fromString(strangs[0]),
+						LazyDice.fromString(strangs[1])));
+			} else if (tok.contains("d") && !tok.equalsIgnoreCase("d")) {
+				/*
+				 * Handle dice groups
+				 */
+				dexps.push(LazyDice.fromString(tok));
 			} else {
 				try {
+					/*
+					 * Handle scalar numbers
+					 */
 					dexps.push(new ScalarDie(Integer.parseInt(tok)));
 				} catch (NumberFormatException nfex) {
 
-					DiceExpression l = dexps.pop();
-					DiceExpression r = dexps.pop();
+					/*
+					 * Apply an operation to two dice
+					 */
+					IDiceExpression l = dexps.pop();
+					IDiceExpression r = dexps.pop();
 
 					switch (tok) {
 						case "+":
@@ -45,13 +98,26 @@ public class DiceExpressionParser {
 							dexps.push(new CompoundDiceExpression(l, r,
 									DiceExpressionType.DIVIDE));
 							break;
+						case "c":
+							dexps.push(new CompoundDice(l, r));
+							break;
+						case "d":
+							dexps.push(new LazyDice(l, r));
+							break;
 						default:
-							throw new IllegalStateException("Detected invalid operator " + tok);
+							/*
+							 * Tell the user the operator is invalid
+							 */
+							throw new IllegalStateException(
+									"Detected invalid operator " + tok);
 					}
 				}
 			}
 		});
 
+		/*
+		 * Return the built expression
+		 */
 		return dexps.pop();
 	}
 }
-- 
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