• Saaa (45/45) Mar 25 2009 I filled in the Phobos implementation, but I'm not sure if it is all cor...
• Sergey Gromov (7/21) Mar 25 2009 Obviously NumberFormatException can store another exception object
• Saaa (10/22) Mar 25 2009 class NumberFormatException : IllegalArgumentException {
• Sergey Gromov (10/30) Mar 25 2009 No it cannot. Object is the root of the D class hierarchy. In D1

"Saaa" <empty needmail.com> writes:

I filled in the Phobos implementation, but I'm not sure if it is all correct 
as I don't fully understand the exception handling.

module java.lang.Byte;

import java.lang.util;
import java.lang.exceptions;

version(Tango){
    static import tango.text.convert.Integer;
} else { // Phobos
    static import std.conv;
}
class Byte : ValueWrapperT!(byte) {
    public static byte parseByte( String s ){
        version(Tango){
            try{
                int res = tango.text.convert.Integer.parse( s );
                if( res < byte.min || res > byte.max ){
                    throw new NumberFormatException( "out of range" );
                }
                return res;
            }
            catch( IllegalArgumentException e ){
//How does this work? It catches e and gives it as an argument to a new 
exception.
                throw new NumberFormatException( e );
            }
        } else if version(Phobos){ // Phobos
            try{
                byte res = to!(byte)(s);
                return res;
            }
            catch(Object e){ // ConvError or ConvOverflowError
//Is this the correct translation?
                throw new NumberFormatException( e );
            }
            return 0;
        }
    }
    this( byte value ){
        super( value );
    }

    public static String toString( byte i ){
        return String_valueOf(i);
    }

}
alias Byte ValueWrapperByte; 

Sergey Gromov <snake.scaly gmail.com> writes:

Thu, 26 Mar 2009 00:29:44 +0100, Saaa wrote:

 I filled in the Phobos implementation, but I'm not sure if it is all correct 
 as I don't fully understand the exception handling.
 
 [...]

             catch( IllegalArgumentException e ){
 //How does this work? It catches e and gives it as an argument to a new 
 exception.
                 throw new NumberFormatException( e );
             }

Obviously NumberFormatException can store another exception object
inside.  This code effectively converts IllegalArgumentException into
NumberFormatException, storing the original argument exception inside so
that one can examine it later if they're curious.

 [...]

             catch(Object e){ // ConvError or ConvOverflowError
 //Is this the correct translation?
                 throw new NumberFormatException( e );
             }

It depends on what NumberFormatException can  accept as an argument.  If
it accepts an Object then it's fine.

"Saaa" <empty needmail.com> writes:

 Obviously NumberFormatException can store another exception object
 inside.  This code effectively converts IllegalArgumentException into
 NumberFormatException, storing the original argument exception inside so
 that one can examine it later if they're curious.

Thanks, yes this is obvious...

 [...]

             catch(Object e){ // ConvError or ConvOverflowError
 //Is this the correct translation?
                 throw new NumberFormatException( e );
             }

 It depends on what NumberFormatException can  accept as an argument.  If
 it accepts an Object then it's fine.

class NumberFormatException : IllegalArgumentException {
    this( String e ){
        super(e);
    }
    this( Exception e ){
        super(e.toString);
    }
}

Can Object be implicitly converted to Exception?

Sergey Gromov <snake.scaly gmail.com> writes:

Thu, 26 Mar 2009 01:40:25 +0100, Saaa wrote:

 [...]

             catch(Object e){ // ConvError or ConvOverflowError
 //Is this the correct translation?
                 throw new NumberFormatException( e );
             }

 It depends on what NumberFormatException can  accept as an argument.  If
 it accepts an Object then it's fine.

 
 class NumberFormatException : IllegalArgumentException {
     this( String e ){
         super(e);
     }
     this( Exception e ){
         super(e.toString);
     }
 }
 
 Can Object be implicitly converted to Exception?

No it cannot.  Object is the root of the D class hierarchy.  In D1
Exception is derived directly from Object.  In D2 Exception is derived
from Throwable which in turn is derived from Object.  You can cast
Exception to Object but not the other way around.

What's worse, ConvError and ConvOverflowError in D2 are derived from
Error which is a separate class from Exception and cannot be cast
implicitly.  I think you'd want to fix the NumberFormatException to
accept Throwable for instance which is a base of both Exception and
Error in D2.