FFIIntegerTypes inheritance hierarchy

> I'm looking through the keyhole at something new to me, so maybe this
> is off base, but looking at the inheritance hierarchy...
>
> FFIIntegerType
>     FFIUint16
>         FFIUint16
>     FFIUInt32
>         FFIInt32
>     FFIUint64
>         FFIInt64
>     FFIUint8
>         FFIInt8
>
> I'm curious... why the all the Ints inherit from the UInts?
>
> Each of those classes has the same two methods #basicHandle:at: and
> #basicHandle:at:put.   So the Int subclasses fully override the
> superclass methods. So there in no inherited behaviour on the instance
> side.
>
> On the class side, I see #externalTypeSize is inherited by the Ints,
> but evaluating...
>     FFIIntegerType allSubclasses collect: [ :class |
>            class externalType byteSize -> class externalTypeSize ]
> produces...
> 4->4
> 2->2
> 4->4
> 8->8
> 1->1
> 2->2
> 4->4
> 8->8
> 1->1
>
> So naively the extra inheritance level seems unnecessary
> and perhaps having...
>     FFIIntegerType class >> externalTypeSize
>         ^ self externalType byteSize
>
> would allow the hierarchy to be flattened.  Maybe not a great benefit,
> except to avoid the next person wondering the same thing :P

>
> and I'm curious why #unsignedLongLongAt: is not used.
> Seems I had the same question a year ago...
>
> On 1 September 2016 at 22:09, Ben Coman <[hidden email]> wrote:
>> I'm looking through the keyhole at something new to me, so maybe this
>> is off base, but looking at the inheritance hierarchy...
>>
>> FFIIntegerType
>>    FFIUint16
>>        FFIUint16
>>    FFIUInt32
>>        FFIInt32
>>    FFIUint64
>>        FFIInt64
>>    FFIUint8
>>        FFIInt8
>>
>> I'm curious... why the all the Ints inherit from the UInts?
>>
>> Each of those classes has the same two methods #basicHandle:at: and
>> #basicHandle:at:put.   So the Int subclasses fully override the
>> superclass methods. So there in no inherited behaviour on the instance
>> side.
>>
>> On the class side, I see #externalTypeSize is inherited by the Ints,
>> but evaluating...
>>    FFIIntegerType allSubclasses collect: [ :class |
>>           class externalType byteSize -> class externalTypeSize ]
>> produces...
>> 4->4
>> 2->2
>> 4->4
>> 8->8
>> 1->1
>> 2->2
>> 4->4
>> 8->8
>> 1->1
>>
>> So naively the extra inheritance level seems unnecessary
>> and perhaps having...
>>    FFIIntegerType class >> externalTypeSize
>>        ^ self externalType byteSize
>>
>> would allow the hierarchy to be flattened.  Maybe not a great benefit,
>> except to avoid the next person wondering the same thing :P
>
> Perhaps its significantly faster to have the method directly return
> the integer rather than do a few more message sends (??)
>
> cheers -ben
>
>>
>>
>> Also, it is surprising that that FFUInt64 uses #signedLongLongAt:
>> rather than #unsignedLongLongAt: .  This seems on-purpose rather than
>> accidental since its inherited by FFIInt64, so it seems there is
>> something interesting to learn here that would benefit a method
>> comment.
>>
>> cheers -ben
>