Checking in stuff

[IRC.git] / Robust / cup / java_cup / parse_action_table.java

diff --git a/Robust/cup/java_cup/parse_action_table.java b/Robust/cup/java_cup/parse_action_table.java
new file mode 100644 (file)
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+++ b/Robust/cup/java_cup/parse_action_table.java
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+
+package java_cup;
+
+import java.util.Enumeration;
+
+/** This class represents the complete "action" table of the parser. 
+ *  It has one row for each state in the parse machine, and a column for
+ *  each terminal symbol.  Each entry in the table represents a shift,
+ *  reduce, or an error.  
+ *
+ * @see     java_cup.parse_action
+ * @see     java_cup.parse_action_row
+ * @version last updated: 11/25/95
+ * @author  Scott Hudson
+ */
+public class parse_action_table {
+
+  /*-----------------------------------------------------------*/
+  /*--- Constructor(s) ----------------------------------------*/
+  /*-----------------------------------------------------------*/
+
+  /** Simple constructor.  All terminals, non-terminals, and productions must 
+   *  already have been entered, and the viable prefix recognizer should
+   *  have been constructed before this is called.
+   */
+  public parse_action_table()
+    {
+      /* determine how many states we are working with */
+      _num_states = lalr_state.number();
+
+      /* allocate the array and fill it in with empty rows */
+      under_state = new parse_action_row[_num_states];
+      for (int i=0; i<_num_states; i++)
+       under_state[i] = new parse_action_row();
+    }
+
+  /*-----------------------------------------------------------*/
+  /*--- (Access to) Instance Variables ------------------------*/
+  /*-----------------------------------------------------------*/
+
+  /** How many rows/states are in the machine/table. */
+  protected int _num_states;
+
+  /** How many rows/states are in the machine/table. */
+  public int num_states() {return _num_states;}
+
+  /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
+
+  /** Actual array of rows, one per state. */
+  public  parse_action_row[] under_state;
+
+  /*-----------------------------------------------------------*/
+  /*--- General Methods ---------------------------------------*/
+  /*-----------------------------------------------------------*/
+
+  /** Check the table to ensure that all productions have been reduced. 
+   *  Issue a warning message (to System.err) for each production that
+   *  is never reduced.
+   */
+  public void check_reductions()
+    throws internal_error
+    {
+      parse_action act;
+      production   prod;
+
+      /* tabulate reductions -- look at every table entry */
+      for (int row = 0; row < num_states(); row++)
+       {
+         for (int col = 0; col < under_state[row].size(); col++)
+           {
+             /* look at the action entry to see if its a reduce */
+             act = under_state[row].under_term[col];
+             if (act != null && act.kind() == parse_action.REDUCE)
+               {
+                 /* tell production that we used it */
+                 ((reduce_action)act).reduce_with().note_reduction_use();
+               }
+           }
+       }
+
+      /* now go across every production and make sure we hit it */
+      for (Enumeration p = production.all(); p.hasMoreElements(); )
+       {
+         prod = (production)p.nextElement();
+
+         /* if we didn't hit it give a warning */
+         if (prod.num_reductions() == 0)
+           {
+             /* count it *
+             emit.not_reduced++;
+
+             /* give a warning if they haven't been turned off */
+             if (!emit.nowarn)
+               {
+                 System.err.println("*** Production \"" + 
+                                 prod.to_simple_string() + "\" never reduced");
+                 lexer.warning_count++;
+               }
+           }
+       }
+    }
+
+  /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*
+
+  /** Convert to a string. */
+  public String toString()
+    {
+      String result;
+      int cnt;
+
+      result = "-------- ACTION_TABLE --------\n";
+      for (int row = 0; row < num_states(); row++)
+       {
+         result += "From state #" + row + "\n";
+         cnt = 0;
+         for (int col = 0; col < under_state[row].size(); col++)
+           {
+             /* if the action is not an error print it */ 
+             if (under_state[row].under_term[col].kind() != parse_action.ERROR)
+               {
+                 result += " [term " + col + ":" + under_state[row].under_term[col] + "]";
+
+                 /* end the line after the 2nd one */
+                 cnt++;
+                 if (cnt == 2)
+                   {
+                     result += "\n";
+                     cnt = 0;
+                   }
+               }
+           }
+          /* finish the line if we haven't just done that */
+         if (cnt != 0) result += "\n";
+       }
+      result += "------------------------------";
+
+      return result;
+    }
+
+  /*-----------------------------------------------------------*/
+
+}
+