package votorola.g.lang; // Copyright 2006-2007, Michael Allan.  Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Votorola Software"), to deal in the Votorola Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicence, and/or sell copies of the Votorola Software, and to permit persons to whom the Votorola Software is furnished to do so, subject to the following conditions: The preceding copyright notice and this permission notice shall be included in all copies or substantial portions of the Votorola Software. THE VOTOROLA SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE VOTOROLA SOFTWARE OR THE USE OR OTHER DEALINGS IN THE VOTOROLA SOFTWARE.

import java.io.PrintStream;


/** A catcher of errors and exceptions.
  *
  * <p>Subtype implementers note: if adding catch methods, bear in mind that dispatch is
  * decided according to formal parameter type at compile time; not actual type at runtime
  * - unlike catch statement parameters.  Best to use a new, distinct name for each new
  * method; rather than overload the ones defined here.</p>
  */
public interface Catcher<S>
{


   // - C a t c h e r --------------------------------------------------------------------


    /** Handles an error. Implementations would normally re-throw it as quickly as
      * possible, taking care not to drop it first.
      *
      *     @param source The logical source of the error.
      */
    public void catchError( S source, Error r );



    /** Handles an exception.
      *
      *     @param source The logical source of the exception.
      */
    public void catchException( S source, Exception x );



   // ====================================================================================


    /** Catcher utilities.
      */
    public @ThreadSafe static final class U
    {

        private U() {}


        /** Prints a source indication and a stack trace, to the stream.
          */
        public static void printStackTrace( final Object source, final Throwable t,
          final PrintStream stream )
        {
            String s;
            try{ s = source.toString(); }
            catch( Exception xS ) { s = "unknown"; }
            stream.print( "CLASS " + source.getClass().getName() + "  INSTANCE " + s + "  THREW " );
            t.printStackTrace( stream );
        }


    }


}