Merge remote-tracking branch 'sharwell/serialization-type'

runtime/Java/src/org/antlr/v4/runtime/atn/ActionTransition.java

@@ -31,7 +31,7 @@ package org.antlr.v4.runtime.atn;
 
 import org.antlr.v4.runtime.misc.NotNull;
 
-public class ActionTransition extends Transition {
+public final class ActionTransition extends Transition {
 	public final int ruleIndex;
 	public final int actionIndex;
 	public final boolean isCtxDependent; // e.g., $i ref in action
@@ -47,6 +47,11 @@ public class ActionTransition extends Transition {
 		this.isCtxDependent = isCtxDependent;
 	}
 
+	@Override
+	public int getSerializationType() {
+		return ACTION;
+	}
+
 	@Override
 	public boolean isEpsilon() {
 		return true; // we are to be ignored by analysis 'cept for predicates

runtime/Java/src/org/antlr/v4/runtime/atn/AtomTransition.java

@@ -33,7 +33,7 @@ import org.antlr.v4.runtime.misc.NotNull;
 import org.antlr.v4.runtime.misc.IntervalSet;
 
 /** TODO: make all transitions sets? no, should remove set edges */
-public class AtomTransition extends Transition {
+public final class AtomTransition extends Transition {
 	/** The token type or character value; or, signifies special label. */
 	public final int label;
 
@@ -42,6 +42,11 @@ public class AtomTransition extends Transition {
 		this.label = label;
 	}
 
+	@Override
+	public int getSerializationType() {
+		return ATOM;
+	}
+
 	@Override
 	@NotNull
 	public IntervalSet label() { return IntervalSet.of(label); }

runtime/Java/src/org/antlr/v4/runtime/atn/EpsilonTransition.java

@@ -31,9 +31,14 @@ package org.antlr.v4.runtime.atn;
 
 import org.antlr.v4.runtime.misc.NotNull;
 
-public class EpsilonTransition extends Transition {
+public final class EpsilonTransition extends Transition {
 	public EpsilonTransition(@NotNull ATNState target) { super(target); }
 
+	@Override
+	public int getSerializationType() {
+		return EPSILON;
+	}
+
 	@Override
 	public boolean isEpsilon() { return true; }
 

runtime/Java/src/org/antlr/v4/runtime/atn/LexerATNSimulator.java

@@ -452,7 +452,8 @@ public class LexerATNSimulator extends ATNSimulator {
 
 	@Nullable
 	public ATNState getReachableTarget(Transition trans, int t) {
-		if ( trans instanceof AtomTransition ) {
+		switch (trans.getSerializationType()) {
+		case Transition.ATOM:
 			AtomTransition at = (AtomTransition)trans;
 			if ( at.label == t ) {
 				if ( debug ) {
@@ -461,8 +462,10 @@ public class LexerATNSimulator extends ATNSimulator {
 
 				return at.target;
 			}
-		}
-		else if ( trans.getClass() == RangeTransition.class ) {
+
+			return null;
+
+		case Transition.RANGE:
 			RangeTransition rt = (RangeTransition)trans;
 			if ( t>=rt.from && t<=rt.to ) {
 				if ( debug ) {
@@ -471,24 +474,44 @@ public class LexerATNSimulator extends ATNSimulator {
 
 				return rt.target;
 			}
-		}
-		else if ( trans instanceof SetTransition ) {
+
+			return null;
+			
+		case Transition.SET:
 			SetTransition st = (SetTransition)trans;
-			boolean not = trans instanceof NotSetTransition;
-			if ( (!not && st.set.contains(t)) ||
-				 (not && !st.set.contains(t) && t!=CharStream.EOF) ) // ~set doesn't not match EOF
-			{
+			if ( st.set.contains(t) ) {
 				if ( debug ) {
-					System.out.format("match %sset %s\n", not ? "~" : "", st.set.toString(true));
+					System.out.format("match set %s\n", st.set.toString(true));
 				}
 
 				return st.target;
 			}
+
+			return null;
+
+		case Transition.NOT_SET:
+			NotSetTransition nst = (NotSetTransition)trans;
+			if (!nst.set.contains(t) && t!=CharStream.EOF) // ~set doesn't not match EOF
+			{
+				if ( debug ) {
+					System.out.format("match ~set %s\n", nst.set.toString(true));
+				}
+
+				return nst.target;
+			}
+
+			return null;
+			
+		case Transition.WILDCARD:
+			if (t != CharStream.EOF) {
+				return trans.target;
+			}
+			
+			return null;
+			
+		default:
+			return null;
 		}
-		else if ( trans instanceof WildcardTransition && t!=CharStream.EOF ) {
-			return trans.target;
-		}
-		return null;
 	}
 
 	public void deleteWildcardConfigsForAlt(@NotNull ATNConfigSet closure, int ci, int alt) {
@@ -572,13 +595,16 @@ public class LexerATNSimulator extends ATNSimulator {
 									  @NotNull ATNConfigSet configs)
 	{
 		ATNState p = config.state;
-		ATNConfig c = null;
-		if ( t.getClass() == RuleTransition.class ) {
+		ATNConfig c;
+
+		switch (t.getSerializationType()) {
+		case Transition.RULE:
 			RuleContext newContext =
 				new RuleContext(config.context, p.stateNumber);
 			c = new ATNConfig(config, t.target, newContext);
-		}
-		else if ( t.getClass() == PredicateTransition.class ) {
+			break;
+			
+		case Transition.PREDICATE:
 			if (recog == null) {
 				System.out.format("Predicates cannot be evaluated without a recognizer; assuming true.\n");
 			}
@@ -609,15 +635,27 @@ public class LexerATNSimulator extends ATNSimulator {
 			if ( recog == null || recog.sempred(null, pt.ruleIndex, pt.predIndex) ) {
 				c = new ATNConfig(config, t.target, pt.getPredicate());
 			}
-		}
-		// ignore actions; just exec one per rule upon accept
-		else if ( t.getClass() == ActionTransition.class ) {
+			else {
+				c = null;
+			}
+			
+			break;
+			
+		case Transition.ACTION:
+			// ignore actions; just exec one per rule upon accept
 			c = new ATNConfig(config, t.target);
 			c.lexerActionIndex = ((ActionTransition)t).actionIndex;
-		}
-		else if ( t.isEpsilon() ) {
+			break;
+			
+		case Transition.EPSILON:
 			c = new ATNConfig(config, t.target);
+			break;
+
+		default:
+			c = null;
+			break;
 		}
+
 		return c;
 	}
 

runtime/Java/src/org/antlr/v4/runtime/atn/NotSetTransition.java

@@ -33,11 +33,16 @@ import org.antlr.v4.runtime.misc.IntervalSet;
 import org.antlr.v4.runtime.misc.NotNull;
 import org.antlr.v4.runtime.misc.Nullable;
 
-public class NotSetTransition extends SetTransition {
+public final class NotSetTransition extends SetTransition {
 	public NotSetTransition(@NotNull ATNState target, @Nullable IntervalSet set) {
 		super(target, set);
 	}
 
+	@Override
+	public int getSerializationType() {
+		return NOT_SET;
+	}
+
 	@Override
 	public String toString() {
 		return '~'+super.toString();

runtime/Java/src/org/antlr/v4/runtime/atn/ParserATNSimulator.java

@@ -737,27 +737,49 @@ public class ParserATNSimulator<Symbol extends Token> extends ATNSimulator {
 
 	@Nullable
 	public ATNState getReachableTarget(@NotNull Transition trans, int ttype) {
-		if ( trans instanceof AtomTransition ) {
+		switch (trans.getSerializationType()) {
+		case Transition.ATOM:
 			AtomTransition at = (AtomTransition)trans;
 			if ( at.label == ttype ) {
 				return at.target;
 			}
-		}
-		else if ( trans instanceof SetTransition ) {
+
+			return null;
+
+		case Transition.SET:
 			SetTransition st = (SetTransition)trans;
-			boolean not = trans instanceof NotSetTransition;
-			if ( !not && st.set.contains(ttype) || not && !st.set.contains(ttype) ) {
+			if ( st.set.contains(ttype) ) {
 				return st.target;
 			}
-		}
-		else if ( trans instanceof RangeTransition ) { // TODO: can't happen in parser, right? remove
+
+			return null;
+
+		case Transition.NOT_SET:
+			NotSetTransition nst = (NotSetTransition)trans;
+			if ( !nst.set.contains(ttype) ) {
+				return nst.target;
+			}
+
+			return null;
+
+		case Transition.RANGE:
 			RangeTransition rt = (RangeTransition)trans;
-			if ( ttype>=rt.from && ttype<=rt.to ) return rt.target;
+			if ( ttype>=rt.from && ttype<=rt.to ) {
+				return rt.target;
+			}
+
+			return null;
+
+		case Transition.WILDCARD:
+			if (ttype != Token.EOF) {
+				return trans.target;
+			}
+
+			return null;
+
+		default:
+			return null;
 		}
-		else if ( trans instanceof WildcardTransition && ttype!=Token.EOF ) {
-			return trans.target;
-		}
-		return null;
 	}
 
 	/** collect and set D's semantic context */
@@ -1023,19 +1045,22 @@ public class ParserATNSimulator<Symbol extends Token> extends ATNSimulator {
 
 	@Nullable
 	public ATNConfig getEpsilonTarget(@NotNull ATNConfig config, @NotNull Transition t, boolean collectPredicates, boolean inContext) {
-		if ( t instanceof RuleTransition ) {
+		switch (t.getSerializationType()) {
+		case Transition.RULE:
 			return ruleTransition(config, t);
-		}
-		else if ( t instanceof PredicateTransition ) {
+
+		case Transition.PREDICATE:
 			return predTransition(config, (PredicateTransition)t, collectPredicates, inContext);
-		}
-		else if ( t instanceof ActionTransition ) {
+
+		case Transition.ACTION:
 			return actionTransition(config, (ActionTransition)t);
-		}
-		else if ( t.isEpsilon() ) {
+
+		case Transition.EPSILON:
 			return new ATNConfig(config, t.target);
+
+		default:
+			return null;
 		}
-		return null;
 	}
 
 	@NotNull

runtime/Java/src/org/antlr/v4/runtime/atn/PredicateTransition.java

@@ -37,7 +37,7 @@ import org.antlr.v4.runtime.misc.NotNull;
  *  may have to combine a bunch of them as it collects predicates from
  *  multiple ATN configurations into a single DFA state.
  */
-public class PredicateTransition extends Transition {
+public final class PredicateTransition extends Transition {
 	public final int ruleIndex;
 	public final int predIndex;
 	public final boolean isCtxDependent;  // e.g., $i ref in pred
@@ -49,6 +49,11 @@ public class PredicateTransition extends Transition {
 		this.isCtxDependent = isCtxDependent;
 	}
 
+	@Override
+	public int getSerializationType() {
+		return PREDICATE;
+	}
+
 	@Override
 	public boolean isEpsilon() { return true; }
 

runtime/Java/src/org/antlr/v4/runtime/atn/RangeTransition.java

@@ -32,7 +32,7 @@ package org.antlr.v4.runtime.atn;
 import org.antlr.v4.runtime.misc.NotNull;
 import org.antlr.v4.runtime.misc.IntervalSet;
 
-public class RangeTransition extends Transition {
+public final class RangeTransition extends Transition {
 	public final int from;
 	public final int to;
 
@@ -42,6 +42,11 @@ public class RangeTransition extends Transition {
 		this.to = to;
 	}
 
+	@Override
+	public int getSerializationType() {
+		return RANGE;
+	}
+
 	@Override
 	@NotNull
 	public IntervalSet label() { return IntervalSet.of(from, to); }

runtime/Java/src/org/antlr/v4/runtime/atn/RuleTransition.java

@@ -32,7 +32,7 @@ package org.antlr.v4.runtime.atn;
 import org.antlr.v4.runtime.misc.NotNull;
 
 /** */
-public class RuleTransition extends Transition {
+public final class RuleTransition extends Transition {
 	/** Ptr to the rule definition object for this rule ref */
 	public final int ruleIndex;     // no Rule object at runtime
 
@@ -49,6 +49,11 @@ public class RuleTransition extends Transition {
 		this.followState = followState;
 	}
 
+	@Override
+	public int getSerializationType() {
+		return RULE;
+	}
+
 	@Override
 	public boolean isEpsilon() { return true; }
 }

runtime/Java/src/org/antlr/v4/runtime/atn/SetTransition.java

@@ -46,6 +46,11 @@ public class SetTransition extends Transition {
 		this.set = set;
 	}
 
+	@Override
+	public int getSerializationType() {
+		return SET;
+	}
+
 	@Override
 	@NotNull
 	public IntervalSet label() { return set; }

runtime/Java/src/org/antlr/v4/runtime/atn/Transition.java

@@ -99,7 +99,7 @@ public abstract class Transition {
 		this.target = target;
 	}
 
-	public int getSerializationType() { return 0; }
+	public abstract int getSerializationType();
 
 	/** Are we epsilon, action, sempred? */
 	public boolean isEpsilon() { return false; }

runtime/Java/src/org/antlr/v4/runtime/atn/WildcardTransition.java

@@ -31,9 +31,14 @@ package org.antlr.v4.runtime.atn;
 
 import org.antlr.v4.runtime.misc.NotNull;
 
-public class WildcardTransition extends Transition {
+public final class WildcardTransition extends Transition {
 	public WildcardTransition(@NotNull ATNState target) { super(target); }
 
+	@Override
+	public int getSerializationType() {
+		return WILDCARD;
+	}
+
 	@Override
 	@NotNull
 	public String toString() {