Make the node labels accessible from outside the package

src/main/java/se/lth/sep/Grammar.java

@@ -8,6 +8,7 @@ public class Grammar {
 	private HashMap<Category, Integer> cat2int = new HashMap<>();
 	private HashMap<Integer, Category> int2cat = new HashMap<>();
 	private HashMap<Category, ArrayList<Rule>> grammarRules = new HashMap<>();
+	private HashMap<EarleyRule, Rule> earleyRule2GrammarRule = new HashMap<>();
 
 	private int nonTermIndex = 1;
 	private int termIndex = -1;
@@ -65,7 +66,9 @@ public class Grammar {
 				for (int j = 0; j < body.length; ++j) {
 					body[j] = cat2int.get(b.getBody().get(j));
 				}
-				eBodies.add(new EarleyRule(i, body));
+				EarleyRule eRule = new EarleyRule(i, body);
+				earleyRule2GrammarRule.put(eRule, b);
+				eBodies.add(eRule);
 			}
 			rules.add(eBodies);
 		}
@@ -97,4 +100,11 @@ public class Grammar {
 			throw new EarleyException("Category not present in the gramamr");
 		return i;
 	}
+
+	public Rule getRule(EarleyRule rule) {
+		Rule r = earleyRule2GrammarRule.get(rule);
+		if (r == null)
+			throw new EarleyException("Rule not preset in the grammar");
+		return r;
+	}
 }

src/main/java/se/lth/sep/NodeLabel.java

@@ -20,49 +20,3 @@ public abstract class NodeLabel {
 
 	public abstract String prettyPrint(Grammar info);
 }
-
-class ItemLabel extends NodeLabel {
-	DottedRule item;
-	public ItemLabel(DottedRule item, int start, int end) {
-		super(start, end);
-		this.item = item;
-	}
-
-	@Override public boolean equals(Object other) {
-		if (!super.equals(other))
-			return false;
-		return  (other instanceof ItemLabel) &&
-			item.equals(((ItemLabel)other).item);
-	}
-
-	@Override public int hashCode() {
-		return super.hashCode() * 31 + item.hashCode();
-	}
-
-	public String prettyPrint(Grammar info) {
-		return item.prettyPrint(info) + ", " + super.start + ", " + super.end;
-	}
-}
-
-class SymbolLabel extends NodeLabel {
-	int symbol;
-	public SymbolLabel(int symbol, int start, int end) {
-		super(start, end);
-		this.symbol = symbol;
-	}
-
-	@Override public boolean equals(Object other) {
-		if (!super.equals(other))
-			return false;
-		return (other instanceof SymbolLabel) &&
-			((SymbolLabel)other).symbol == symbol;
-	}
-
-	@Override public int hashCode() {
-		return super.hashCode() * 31 + symbol;
-	}
-
-	public String prettyPrint(Grammar info) {
-		return info.getCategory(symbol).toString() + ", " + super.start + ", " + super.end;
-	}
-}