org.antlr.v4.runtime.atn.ATNSimulator Maven / Gradle / Ivy
/*
* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
* Use of this file is governed by the BSD 3-clause license that
* can be found in the LICENSE.txt file in the project root.
*/
package org.antlr.v4.runtime.atn;
import org.antlr.v4.runtime.dfa.DFAState;
import org.antlr.v4.runtime.misc.IntervalSet;
import java.util.IdentityHashMap;
import java.util.List;
import java.util.UUID;
public abstract class ATNSimulator {
/**
* @deprecated Use {@link ATNDeserializer#SERIALIZED_VERSION} instead.
*/
@Deprecated
public static final int SERIALIZED_VERSION;
static {
SERIALIZED_VERSION = ATNDeserializer.SERIALIZED_VERSION;
}
/**
* This is the current serialized UUID.
* @deprecated Use {@link ATNDeserializer#checkCondition(boolean)} instead.
*/
@Deprecated
public static final UUID SERIALIZED_UUID;
static {
SERIALIZED_UUID = ATNDeserializer.SERIALIZED_UUID;
}
/** Must distinguish between missing edge and edge we know leads nowhere */
public static final DFAState ERROR;
public final ATN atn;
/** The context cache maps all PredictionContext objects that are equals()
* to a single cached copy. This cache is shared across all contexts
* in all ATNConfigs in all DFA states. We rebuild each ATNConfigSet
* to use only cached nodes/graphs in addDFAState(). We don't want to
* fill this during closure() since there are lots of contexts that
* pop up but are not used ever again. It also greatly slows down closure().
*
* This cache makes a huge difference in memory and a little bit in speed.
* For the Java grammar on java.*, it dropped the memory requirements
* at the end from 25M to 16M. We don't store any of the full context
* graphs in the DFA because they are limited to local context only,
* but apparently there's a lot of repetition there as well. We optimize
* the config contexts before storing the config set in the DFA states
* by literally rebuilding them with cached subgraphs only.
*
* I tried a cache for use during closure operations, that was
* whacked after each adaptivePredict(). It cost a little bit
* more time I think and doesn't save on the overall footprint
* so it's not worth the complexity.
*/
protected final PredictionContextCache sharedContextCache;
static {
ERROR = new DFAState(new ATNConfigSet());
ERROR.stateNumber = Integer.MAX_VALUE;
}
public ATNSimulator(ATN atn,
PredictionContextCache sharedContextCache)
{
this.atn = atn;
this.sharedContextCache = sharedContextCache;
}
public abstract void reset();
/**
* Clear the DFA cache used by the current instance. Since the DFA cache may
* be shared by multiple ATN simulators, this method may affect the
* performance (but not accuracy) of other parsers which are being used
* concurrently.
*
* @throws UnsupportedOperationException if the current instance does not
* support clearing the DFA.
*
* @since 4.3
*/
public void clearDFA() {
throw new UnsupportedOperationException("This ATN simulator does not support clearing the DFA.");
}
public PredictionContextCache getSharedContextCache() {
return sharedContextCache;
}
public PredictionContext getCachedContext(PredictionContext context) {
if ( sharedContextCache==null ) return context;
synchronized (sharedContextCache) {
IdentityHashMap visited =
new IdentityHashMap();
return PredictionContext.getCachedContext(context,
sharedContextCache,
visited);
}
}
/**
* @deprecated Use {@link ATNDeserializer#deserialize} instead.
*/
@Deprecated
public static ATN deserialize(char[] data) {
return new ATNDeserializer().deserialize(data);
}
/**
* @deprecated Use {@link ATNDeserializer#checkCondition(boolean)} instead.
*/
@Deprecated
public static void checkCondition(boolean condition) {
new ATNDeserializer().checkCondition(condition);
}
/**
* @deprecated Use {@link ATNDeserializer#checkCondition(boolean, String)} instead.
*/
@Deprecated
public static void checkCondition(boolean condition, String message) {
new ATNDeserializer().checkCondition(condition, message);
}
/**
* @deprecated Use {@link ATNDeserializer#toInt} instead.
*/
@Deprecated
public static int toInt(char c) {
return ATNDeserializer.toInt(c);
}
/**
* @deprecated Use {@link ATNDeserializer#toInt32} instead.
*/
@Deprecated
public static int toInt32(char[] data, int offset) {
return ATNDeserializer.toInt32(data, offset);
}
/**
* @deprecated Use {@link ATNDeserializer#toLong} instead.
*/
@Deprecated
public static long toLong(char[] data, int offset) {
return ATNDeserializer.toLong(data, offset);
}
/**
* @deprecated Use {@link ATNDeserializer#toUUID} instead.
*/
@Deprecated
public static UUID toUUID(char[] data, int offset) {
return ATNDeserializer.toUUID(data, offset);
}
/**
* @deprecated Use {@link ATNDeserializer#edgeFactory} instead.
*/
@Deprecated
public static Transition edgeFactory(ATN atn,
int type, int src, int trg,
int arg1, int arg2, int arg3,
List sets)
{
return new ATNDeserializer().edgeFactory(atn, type, src, trg, arg1, arg2, arg3, sets);
}
/**
* @deprecated Use {@link ATNDeserializer#stateFactory} instead.
*/
@Deprecated
public static ATNState stateFactory(int type, int ruleIndex) {
return new ATNDeserializer().stateFactory(type, ruleIndex);
}
}