Make dice generic

Convert dice from dealing exclusively with ints, to deal with objects of
arbitrary types

1 files changed, 96 insertions, 0 deletions

diff --git a/dice/src/main/java/bjc/dicelang/neodice/IDie.java b/dice/src/main/java/bjc/dicelang/neodice/IDie.java
new file mode 100644
index 0000000..274af66
--- /dev/null
+++ b/dice/src/main/java/bjc/dicelang/neodice/IDie.java
@@ -0,0 +1,96 @@
+package bjc.dicelang.neodice;
+
+import java.util.*;
+import java.util.function.*;
+import java.util.stream.*;
+
+import bjc.dicelang.neodice.die.*;
+import bjc.dicelang.neodice.diepool.*;
+
+/**
+ * Represents a single polyhedral die.
+ * @author Ben Culkin
+ *
+ */
+@FunctionalInterface
+public interface IDie<SideType> {
+	/**
+	 * Rolls this die.
+	 * 
+	 * @param rng The source for random numbers
+	 * 
+	 * @return The result of rolling the die.
+	 */
+	public SideType roll(Random rng);
+	
+	/**
+	 * Returns a die pool which rolls this die the specified number of times.
+	 * 
+	 * @param numTimes The number of times to roll this die.
+	 * 
+	 * @return A die pool that rolls this die the specified number of times.
+	 */
+	default IDiePool<SideType> times(int numTimes) {
+		return new ExpandDiePool<>(this, (die, rng) -> {
+			return Stream.generate(() -> die.roll(rng))
+					.limit(numTimes);
+		});
+	};
+	
+	/**
+	 * Returns a die which will reroll this die as long as the provided condition is true.
+	 * 
+	 * @param condition The condition to reroll the die on.
+	 * 
+	 * @return A die that rerolls when the given condition is met.
+	 */
+	default IDie<SideType> reroll(
+			Comparator<SideType> comparer,
+			Predicate<SideType> condition) {
+		return RerollDie.create(comparer, this, condition,
+				(list) -> list.get(list.size()));
+	}
+	
+	/**
+	 * Returns a die which will reroll this die up to a specified number of times,
+	 * as long as the provided condition is true.
+	 * 
+	 * @param condition The condition to reroll the die on.
+	 * @param limit The maximum number of times to reroll the die.
+	 * 
+	 * @return A die that rerolls when the given condition is met.
+	 */
+	default IDie<SideType> reroll(
+			Comparator<SideType> comparer,
+			Predicate<SideType> condition,
+			int limit) {
+		return RerollDie.create(comparer, this, condition,
+				(list) -> list.get(list.size()), limit);
+	}
+	
+	/**
+	 * Create an stream which gives rolls of this dice.
+	 * 
+	 * @param rng The source for random numbers.
+	 * 
+	 * @return An iterator which gives rolls of this dice.
+	 */
+	default Stream<SideType> stream(Random rng) {
+		return Stream.generate(() -> this.roll(rng));
+	}
+	
+	default <NewType> IDie<NewType> transform(Function<SideType, NewType> mapper) {
+		return (rng) -> mapper.apply(this.roll(rng));
+	}
+	
+	/**
+	 * Create a simple polyhedral die with a fixed number of sides.
+	 * 
+	 * @param sides The number of sides for the die.
+	 * 
+	 * @return A die which returns a result from 1 to sides.
+	 */
+	static IDie<Integer> polyhedral(int sides) {
+		return new PolyhedralDie(sides);
+	}
+}
\ No newline at end of file