[Pyobjc-dev] NSDecimalNumber to the next level

[Pierce T.W. I. <pi...@tw...>]

  I want to take NSDecimalNumber to the next level.

  History:

   1.0.

    NSDecimalNumber is wrapped as identical to CFNumber, which turns out 
not work.

   1.1

    NSDecimalNumbers are passed through untransformed, you can use:

   dv=obj.doubleValue() to convert them to Python doubles, then:

    NSDecimalNumber.numberWithDouble(dv) to convert them back. This had 
to happen because the type information was getting lost, and the values 
passed back to Objective-C were plain CFNumber classes, which didn't 
implement NSDecimalNumber.decimalNumberByAdding_(dv), etc.

  1.2?

   I want to work on improving this a bit, so that the NSDecimalNumber 
can be more or less transparent to the user so they can do something 
like this:

  Objc:

  + (NSDecimalNumber *) addOne: (NSDecimalNumber *) value
  {
     return [value decimalNumberByAdding: [NSDecimalNumber one]];
  }

  Python:

     value1 = NSDecimalNumber.zero()
     value1 += 1;
     value2 = NSDecimalNumber.addOne(value1)

     if value2 = 2: print "it works!"

    Right now the first one doesn't work, because Python no longer knows 
that NSDecimalNumber can be used as a double, you have to rewrite it 
as:

     value1 = NSDecimalNumber.zero().doubleValue()
     value1 += 1;
     value2 = NSDecimalNumber.addOne(
                  NSDecimalNumber.numberWithDouble(value1))

     if value2.doubleValue() = 2: print "it works!"

    Which gets cumbersome quickly...


  I'll do the work if someone can give me a bit of an outline on what I 
need to do, or perhaps can point me at a class that has been custom 
bridged that I can crib from?

   Pierce