All Downloads are FREE. Search and download functionalities are using the official Maven repository.

org.antlr.v4.runtime.atn.ATNSimulator Maven / Gradle / Ivy

Go to download

Statistical sampling library for use in virtdata libraries, based on apache commons math 4

There is a newer version: 5.17.0
Show newest version
/*
 * 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); } }




© 2015 - 2024 Weber Informatics LLC | Privacy Policy