original

[gb-231r1-is01/GB_2.3_IS01.git] / cts / tools / dasm / src / java_cup / symbol.java

diff --git a/cts/tools/dasm/src/java_cup/symbol.java b/cts/tools/dasm/src/java_cup/symbol.java
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+++ b/cts/tools/dasm/src/java_cup/symbol.java
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+package java_cup;
+
+/** This abstract class serves as the base class for grammar symbols (i.e.,
+ * both terminals and non-terminals).  Each symbol has a name string, and
+ * a string giving the type of object that the symbol will be represented by
+ * on the runtime parse stack.  In addition, each symbol maintains a use count
+ * in order to detect symbols that are declared but never used, and an index
+ * number that indicates where it appears in parse tables (index numbers are
+ * unique within terminals or non terminals, but not across both).
+ *
+ * @see     java_cup.terminal
+ * @see     java_cup.non_terminal
+ * @version last updated: 11/25/95
+ * @author  Scott Hudson
+ */
+public abstract class symbol {
+   /*-----------------------------------------------------------*/
+   /*--- Constructor(s) ----------------------------------------*/
+   /*-----------------------------------------------------------*/
+
+   /** Full constructor.
+    * @param nm the name of the symbol.
+    * @param tp a string with the type name.
+    */
+   public symbol(String nm, String tp)
+     {
+       /* sanity check */
+       if (nm == null) nm = "";
+
+       /* apply default if no type given */
+       if (tp == null) tp = "java_cup.runtime.token";
+
+       _name = nm;
+       _stack_type = tp;
+     }
+
+  /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
+
+   /** Constructor with default type. 
+    * @param nm the name of the symbol.
+    */
+   public symbol(String nm)
+     {
+       this(nm, null);
+     }
+
+   /*-----------------------------------------------------------*/
+   /*--- (Access to) Instance Variables ------------------------*/
+   /*-----------------------------------------------------------*/
+
+   /** String for the human readable name of the symbol. */
+   protected String _name; 
+ 
+   /** String for the human readable name of the symbol. */
+   public String name() {return _name;}
+
+  /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
+
+   /** String for the type of object used for the symbol on the parse stack. */
+   protected String _stack_type;
+
+   /** String for the type of object used for the symbol on the parse stack. */
+   public String stack_type() {return _stack_type;}
+
+  /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
+
+   /** Count of how many times the symbol appears in productions. */
+   protected int _use_count = 0;
+
+   /** Count of how many times the symbol appears in productions. */
+   public int use_count() {return _use_count;}
+
+   /** Increment the use count. */ 
+   public void note_use() {_use_count++;}
+ 
+  /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
+ 
+  /** Index of this symbol (terminal or non terminal) in the parse tables.
+   *  Note: indexes are unique among terminals and unique among non terminals,
+   *  however, a terminal may have the same index as a non-terminal, etc. 
+   */
+   protected int _index;
+ 
+  /** Index of this symbol (terminal or non terminal) in the parse tables.
+   *  Note: indexes are unique among terminals and unique among non terminals,
+   *  however, a terminal may have the same index as a non-terminal, etc. 
+   */
+   public int index() {return _index;}
+
+  /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
+
+  /** Indicate if this is a non-terminal.  Here in the base class we
+   *  don't know, so this is abstract.  
+   */
+  public abstract boolean is_non_term();
+
+  /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
+
+  /** Convert to a string. */
+  public String toString()
+    {
+      return name();
+    }
+
+  /*-----------------------------------------------------------*/
+
+};