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

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/*
 * 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;

import java.util.Arrays;

/**
 * This class provides a default implementation of the {@link Vocabulary}
 * interface.
 *
 * @author Sam Harwell
 */
public class VocabularyImpl implements Vocabulary {
	private static final String[] EMPTY_NAMES = new String[0];

	/**
	 * Gets an empty {@link Vocabulary} instance.
	 *
	 * 

* No literal or symbol names are assigned to token types, so * {@link #getDisplayName(int)} returns the numeric value for all tokens * except {@link Token#EOF}.

*/ public static final VocabularyImpl EMPTY_VOCABULARY = new VocabularyImpl(EMPTY_NAMES, EMPTY_NAMES, EMPTY_NAMES); private final String[] literalNames; private final String[] symbolicNames; private final String[] displayNames; private final int maxTokenType; /** * Constructs a new instance of {@link VocabularyImpl} from the specified * literal and symbolic token names. * * @param literalNames The literal names assigned to tokens, or {@code null} * if no literal names are assigned. * @param symbolicNames The symbolic names assigned to tokens, or * {@code null} if no symbolic names are assigned. * * @see #getLiteralName(int) * @see #getSymbolicName(int) */ public VocabularyImpl(String[] literalNames, String[] symbolicNames) { this(literalNames, symbolicNames, null); } /** * Constructs a new instance of {@link VocabularyImpl} from the specified * literal, symbolic, and display token names. * * @param literalNames The literal names assigned to tokens, or {@code null} * if no literal names are assigned. * @param symbolicNames The symbolic names assigned to tokens, or * {@code null} if no symbolic names are assigned. * @param displayNames The display names assigned to tokens, or {@code null} * to use the values in {@code literalNames} and {@code symbolicNames} as * the source of display names, as described in * {@link #getDisplayName(int)}. * * @see #getLiteralName(int) * @see #getSymbolicName(int) * @see #getDisplayName(int) */ public VocabularyImpl(String[] literalNames, String[] symbolicNames, String[] displayNames) { this.literalNames = literalNames != null ? literalNames : EMPTY_NAMES; this.symbolicNames = symbolicNames != null ? symbolicNames : EMPTY_NAMES; this.displayNames = displayNames != null ? displayNames : EMPTY_NAMES; // See note here on -1 part: https://github.com/antlr/antlr4/pull/1146 this.maxTokenType = Math.max(this.displayNames.length, Math.max(this.literalNames.length, this.symbolicNames.length)) - 1; } /** * Returns a {@link VocabularyImpl} instance from the specified set of token * names. This method acts as a compatibility layer for the single * {@code tokenNames} array generated by previous releases of ANTLR. * *

The resulting vocabulary instance returns {@code null} for * {@link #getLiteralName(int)} and {@link #getSymbolicName(int)}, and the * value from {@code tokenNames} for the display names.

* * @param tokenNames The token names, or {@code null} if no token names are * available. * @return A {@link Vocabulary} instance which uses {@code tokenNames} for * the display names of tokens. */ public static Vocabulary fromTokenNames(String[] tokenNames) { if (tokenNames == null || tokenNames.length == 0) { return EMPTY_VOCABULARY; } String[] literalNames = Arrays.copyOf(tokenNames, tokenNames.length); String[] symbolicNames = Arrays.copyOf(tokenNames, tokenNames.length); for (int i = 0; i < tokenNames.length; i++) { String tokenName = tokenNames[i]; if (tokenName == null) { continue; } if (!tokenName.isEmpty()) { char firstChar = tokenName.charAt(0); if (firstChar == '\'') { symbolicNames[i] = null; continue; } else if (Character.isUpperCase(firstChar)) { literalNames[i] = null; continue; } } // wasn't a literal or symbolic name literalNames[i] = null; symbolicNames[i] = null; } return new VocabularyImpl(literalNames, symbolicNames, tokenNames); } @Override public int getMaxTokenType() { return maxTokenType; } @Override public String getLiteralName(int tokenType) { if (tokenType >= 0 && tokenType < literalNames.length) { return literalNames[tokenType]; } return null; } @Override public String getSymbolicName(int tokenType) { if (tokenType >= 0 && tokenType < symbolicNames.length) { return symbolicNames[tokenType]; } if (tokenType == Token.EOF) { return "EOF"; } return null; } @Override public String getDisplayName(int tokenType) { if (tokenType >= 0 && tokenType < displayNames.length) { String displayName = displayNames[tokenType]; if (displayName != null) { return displayName; } } String literalName = getLiteralName(tokenType); if (literalName != null) { return literalName; } String symbolicName = getSymbolicName(tokenType); if (symbolicName != null) { return symbolicName; } return Integer.toString(tokenType); } }




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