1 files changed, 134 insertions, 0 deletions
diff --git a/src/main/java/bjc/rgens/parser/Rule.java b/src/main/java/bjc/rgens/parser/Rule.java
new file mode 100644
index 0000000..7043e0f
--- /dev/null
+++ b/src/main/java/bjc/rgens/parser/Rule.java
@@ -0,0 +1,134 @@
+package bjc.rgens.parser;
+
+import bjc.utils.funcdata.FunctionalList;
+import bjc.utils.funcdata.IList;
+
+import java.util.Random;
+
+/**
+ * A rule in a randomized grammar.
+ *
+ * @author EVE
+ */
+public class Rule {
+	/** The name of this grammar rule. */
+	public final String name;
+
+	/* The cases for this rule. */
+	private IList<RuleCase> cases;
+
+	/**
+	 * Create a new grammar rule.
+	 *
+	 * @param ruleName
+	 * 	The name of the grammar rule.
+	 *
+	 * @throws IllegalArgumentException
+	 * 	If the rule name is invalid.
+	 */
+	public Rule(String ruleName) {
+		if (ruleName == null) {
+			throw new NullPointerException("Rule name must not be null");
+		} else if (ruleName.equals("")) {
+			throw new IllegalArgumentException("The empty string is not a valid rule name");
+		}
+
+		name = ruleName;
+
+		cases = new FunctionalList<>();
+	}
+
+	/**
+	 * Adds a case to the rule.
+	 *
+	 * @param cse
+	 * 	The case to add.
+	 */
+	public void addCase(RuleCase cse) {
+		if (cse == null) {
+			throw new NullPointerException("Case must not be null");
+		}
+
+		cases.add(cse);
+	}
+
+	/**
+	 * Get a random case from this rule.
+	 *
+	 * @return
+	 * 	A random case from this rule.
+	 */
+	public RuleCase getCase() {
+		return cases.randItem();
+	}
+
+	/**
+	 * Get a random case from this rule.
+	 *
+	 * @param rnd
+	 * 	The random number generator to use.
+	 *
+	 * @return
+	 * 	A random case from this rule.
+	 */
+	public RuleCase getCase(Random rnd) {
+		return cases.randItem(rnd::nextInt);
+	}
+
+	/**
+	 * Get all the cases of this rule.
+	 *
+	 * @return
+	 * 	All the cases in this rule.
+	 */
+	public IList<RuleCase> getCases() {
+		return cases;
+	}
+
+	/**
+	 * Replace the current list of cases with a new one.
+	 *
+	 * @param cases
+	 * 	The new list of cases.
+	 */
+	public void replaceCases(IList<RuleCase> cases) {
+		this.cases = cases;
+	}
+
+	@Override
+	public int hashCode() {
+		final int prime = 31;
+
+		int result = 1;
+		result = prime * result + ((cases == null) ? 0 : cases.hashCode());
+		result = prime * result + ((name == null) ? 0 : name.hashCode());
+
+		return result;
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if (this == obj) return true;
+
+		if (obj == null) return false;
+
+		if (!(obj instanceof Rule)) return false;
+
+		Rule other = (Rule) obj;
+
+		if (cases == null) {
+			if (other.cases != null) return false;
+		} else if (!cases.equals(other.cases)) return false;
+
+		if (name == null) {
+			if (other.name != null) return false;
+		} else if (!name.equals(other.name)) return false;
+
+		return true;
+	}
+
+	@Override
+	public String toString() {
+		return String.format("Rule [ruleName='%s', ruleCases=%s]", name, cases);
+	}
+}