package dlib;
/*
$Id: Readable_Printer.java 1.2 1996/09/10 02:03:30 ddyer Exp $
$Log: Readable_Printer.java $
Revision 1.2  1996/09/10 02:03:30  ddyer
added list

Revision 1.1  1996/09/07 13:06:00  ddyer
Initial revision

*/

import java.io.*;

/** Readable_Printer is a static class which supplies the two argument 
 version of "Print_Readably", which prints objects in a form compatible
 with Java source files.
 
 this class also illustrates the pain caused because Java isn't a fully
 extensible object environment.  In a better world, we would simply define
 Print_Readably methods directly on the object types (including base types such as "int")
 
@author Dave Dyer <ddyer@netcom.com>
@version 1.0, August 1996
*/
public class Readable_Printer extends BaseObject
{ /** print an expression which casts a containerized primitive type
    (such as Integer or Boolean) to the corresponding primitive type.
    */
  static public void Print_Cast_To_Type(PrintStream out,String objectname,String type)
   { if(type.equals("boolean"))
  	{ out.print("((Boolean)" + objectname + ").booleanValue()" ); }
  	else if(type.equals("char"))
  	{ out.print("((Character)" + objectname + ").charValue()" ); }
 		else if(type.equals("byte"))
  	{ out.print("((byte)((Integer)" + objectname + ").intValue())"); }
 		else if(type.equals("short"))
  	{ out.print("((short)((Integer)" + objectname + ").intValue())" ); }
 		else if(type.equals("int"))
 		{ out.print("((Integer)" + objectname + ").intValue()" ); }
 		else if(type.equals("long"))
  	{ out.print("((Integer)" + objectname + ").longValue()" ); }
 		else if(type.equals("float"))
  	{ out.print("((Float)" + objectname + ").floatValue()" ); }
 		else if(type.equals("double"))
  	{ out.print("((Float)" + objectname + ").doubleValue()" ); }
  	else 
  	{ out.print( "((" + type + ")" + objectname + ")"); } 
   }
  /** print an object which implements the Print_Readable protocol */
	static public void Print_Readably(PrintStream out, Print_Readable object)
	{ object.Print_Readably(out);}
	
	/** print any object readably.  An error is generated if the object
	   doesn't implement the Print_Readable protocol or is not one of
	   the special cases Readable_Printer explicitly handles.  
	 */
	static public void Print_Readably(PrintStream out, Object object)
	{ if(object instanceof String) 
		{ /* note that we need this clause becauase sometimes strings are cast
		   as type "Object" at compile time. */
		 Print_Readably(out,(String)object); 
		}
	  else if(object instanceof Print_Readable) 
	  { Print_Readably(out,(Print_Readable)object); 
	  }
		else 
		{throw new Error("Object " + object + " can't print readably");}
	}
  /** print a string readably.  This prints the enclosing "" and handles
   escaping embedded " and \ characters.  It doesn't handle newlines 
   */
	static public void Print_Readably(PrintStream out, String tf)
  { out.print("\""); 
    for(int i=0,len=tf.length();   i<len; i++)
    { char c = tf.charAt(i);
      if((c=='"') || c=='\\') out.print("\\");
      out.print(c);
    }
    out.print("\"");
  }
  /** print an array or objects readably.  Reading will only work in contexts
  where a static initializer is acceptable.
  */
  static public void Print_Readably(PrintStream out,Object[] arg)
  { out.println();
  	out.print("{");
  	for(int i=0,lim=arg.length-1; i<=lim; i++)
  	 { out.print("	");
  	   Print_Readably(out,arg[i]);
  	   if(i!=lim) out.println(",");
    }
    out.print("}");  
    }
    	
	static public void Print_Readably(PrintStream out, boolean tf) { out.print(tf); }
	static public void Print_Readably(PrintStream out, byte tf) { out.print(tf); }
	static public void Print_Readably(PrintStream out, short tf) { out.print(tf); }
	static public void Print_Readably(PrintStream out, int tf) { out.print(tf); }
	static public void Print_Readably(PrintStream out, float tf) { out.print(tf); }
	static public void Print_Readably(PrintStream out, double tf) { out.print(tf); }
	static public void Print_Readably(PrintStream out, char tf) { out.print("'" + tf + "'" ); }
}