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csjavacc/struct/Expansion.java

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+/*
+ * Copyright © 2002 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * California 95054, U.S.A. All rights reserved.  Sun Microsystems, Inc. has
+ * intellectual property rights relating to technology embodied in the product
+ * that is described in this document. In particular, and without limitation,
+ * these intellectual property rights may include one or more of the U.S.
+ * patents listed at http://www.sun.com/patents and one or more additional
+ * patents or pending patent applications in the U.S. and in other countries.
+ * U.S. Government Rights - Commercial software. Government users are subject
+ * to the Sun Microsystems, Inc. standard license agreement and applicable
+ * provisions of the FAR and its supplements.  Use is subject to license terms.
+ * Sun,  Sun Microsystems,  the Sun logo and  Java are trademarks or registered
+ * trademarks of Sun Microsystems, Inc. in the U.S. and other countries.  This
+ * product is covered and controlled by U.S. Export Control laws and may be
+ * subject to the export or import laws in other countries.  Nuclear, missile,
+ * chemical biological weapons or nuclear maritime end uses or end users,
+ * whether direct or indirect, are strictly prohibited.  Export or reexport
+ * to countries subject to U.S. embargo or to entities identified on U.S.
+ * export exclusion lists, including, but not limited to, the denied persons
+ * and specially designated nationals lists is strictly prohibited.
+ */
+
+package csjavacc.struct;
+
+/**
+ * Describes expansions - entities that may occur on the
+ * right hand sides of productions.  This is the base class of
+ * a bunch of other more specific classes.
+ */
+
+public class Expansion {
+
+  /**
+   * The line and column number of the construct that corresponds
+   * most closely to this node.
+   */
+  public int line, column;
+
+  /**
+   * A reimplementing of Object.hashCode() to be deterministic.  This uses
+   * the line and column fields to generate an arbitrary number - we assume
+   * that this method is called only after line and column are set to
+   * their actual values.
+   */
+  public int hashCode() {
+    return line + column;
+  }
+
+  /**
+   * An internal name for this expansion.  This is used to generate parser
+   * routines.
+   */
+  public String internal_name = "";
+
+  /**
+   * The parser routines are generated in three phases.  The generation
+   * of the second and third phase are on demand only, and the third phase
+   * can be recursive.  This variable is used to keep track of the
+   * expansions for which phase 3 generations have been already added to
+   * a list so that the recursion can be terminated.
+   */
+  public boolean phase3done = false;
+
+  /**
+   * The parent of this expansion node.  In case this is the top level
+   * expansion of the production it is a reference to the production node
+   * otherwise it is a reference to another Expansion node.  In case this
+   * is the top level of a lookahead expansion,then the parent is null.
+   */
+  public Object parent;
+
+  /**
+   * The ordinal of this node with respect to its parent.
+   */
+  public int ordinal;
+
+  /**
+   * To avoid right-recursive loops when calculating follow sets, we use
+   * a generation number which indicates if this expansion was visited
+   * by LookaheadWalk.genFollowSet in the same generation.  New generations
+   * are obtained by incrementing the static counter below, and the current
+   * generation is stored in the non-static variable below.
+   */
+  public static long nextGenerationIndex = 1;
+  public long myGeneration = 0;
+
+  /**
+   * This flag is used for bookkeeping by the minimumSize method in class
+   * ParseEngine.
+   */
+  public boolean inMinimumSize = false;
+
+   public static void reInit()
+   {
+      nextGenerationIndex = 1;
+   }
+
+}