I had also wondered about building Complex out of Point. The taste  
issues here are for Smalltalk
experts, so what I'll do is try to contribute with a quick look at  
the math.

Here's a table that describes some similarities and differences  
between Complex and
Number & Point, respectively.

  Function(s)                            
Number                                Point
+, -                                           must  
extend                         is correct
*,/                                             must  
extend                         wrong, must override
real,imaginary                       must  
extend                         aliases for x,y
reciprocal                               must  
extend                        wrong, must override
a+ib                                         write a + b  
i                          a at b concise but nonstandard
printOn:                                    
extend                                  a at b concise but nonstandard
abs                                           must  
extend                        r, not abs
arg                                            must  
extend                        theta almost right: arbitrary for 0 at 0;  
sloppy accuracy for 0 at 1, different root convention
sin, cos                                    must  
extend                        must extend
degreeCos, degreeSin        copy from Float
interpolation                           leave to  
user                      interpolateTo:at:
isZero                                      must  
extend                        is correct
|a -b|                                        leave to  
user                       a dist: b
rendering on plane               use Point                             
is correct
=                                               must  
extend                        is correct
 >, < etc.                                    return  
error?                       override, return error
adaptToNumber                    must extend                         
is wrong, should be ^ rcvr at 0 perform: selector with: self
asFloatPoint                            must  
extend                       correct?


In the absence of guidance, I'm steaming ahead building on what's  
already there. In the event that the stuff
needs to be moved around, I hope someone out there knows an easy way  
of doing it.

     regards
         ws

On Sep 30, 2005, at 09.13, squeak-dev- 
request at lists.squeakfoundation.org wrote:

> I may be missing something, but is there a specific reason why we  
> do not
> implement complex numbers simply by extending Point ? it would make it
> easier to work with transformations on the complex plane where
> conversion between Point and Complex would happen all the time.
>
>
> Stef
>
>

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