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Lookahead.java

/*
 * Copyright © 2002 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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package org.javacc.parser;

/**
 * Describes lookahead rule for a particular expansion or expansion
 * sequence (See Sequence.java).  In case this describes the lookahead
 * rule for a single expansion unit, then a sequence is created with
 * this node as the first element, and the expansion unit as the second
 * and last element.
 */

00033 public class Lookahead extends Expansion {

  /**
   * Contains the list of tokens that make up the semantic lookahead
   * if any.  If this node represents a different kind of lookahead (other
   * than semantic lookahead), then this vector contains nothing.  If
   * this vector contains something, then it is the boolean expression
   * that forms the semantic lookahead.  In this case, the following
   * fields "amount" and "la_expansion" are ignored.
   */
00043   public java.util.Vector action_tokens = new java.util.Vector();

  /**
   * The lookahead amount.  Its default value essentially gives us
   * infinite lookahead.
   */
00049   public int amount = Integer.MAX_VALUE;

  /**
   * The expansion used to determine whether or not to choose the
   * corresponding parse option.  This expansion is parsed upto
   * "amount" tokens of lookahead or until a complete match for it
   * is found.  Usually, this is the same as the expansion to be
   * parsed.
   */
00058   public Expansion la_expansion;

  /**
   * Is set to true if this is an explicit lookahead specification.
   */
00063   public boolean isExplicit;

}

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