I want to Typename{T,N} as Abstract onlyif Typename.abstract==true,
otherwise Typename.abstract==false and I want to treat it as Concrete
Milan's solution displays the subtypes immediately. The way it is set up
is neat -- but how to pull the targeted type out of the body?
I need this to be a callable function that yields a manipulable tuple or
vector or tuple of subtuples or etc.
On Wednesday, February 10, 2016 at 3:26:14 AM UTC-5, Tommy Hofmann wrote:
>
> I think the recursive solution of Milan will give you a finite list of all
> subtypes. But the list will contain things like Array{T, N}, that is, a
> type with a parameter. How do you handle those? Do you want to count them
> as abstract or concrete?
>
> On Wednesday, February 10, 2016 at 9:10:16 AM UTC+1, Jeffrey Sarnoff wrote:
>>
>> Hello Tommy,
>>
>> OK, putting off inclusion of recursive types ...
>> and ignoring all possible values for the parameters of a parameterized
>> type unless already explicitly defined (present in memory) ...
>>
>> allsupertypes(T) should be a short list from T to supertype(T) to
>> supertype(supertype(T)) .. to Any
>>
>> allsubtypes(T) seems obtainable
>> I can throw things into a tree until the leaves have no subtypes,
>> then traverse it; is there a nice way to do that implicitly within a
>> function?
>>
>>
>>
>>
>> On Wednesday, February 10, 2016 at 2:32:35 AM UTC-5, Tommy Hofmann wrote:
>>>
>>> You implicitly assume that a type has only finitely many sub/supertypes,
>>> which for arbitrary types is clearly not the case. The simplest example is
>>> Any but you can also get this behavior when defining recursive types. More
>>> generally, given types TL, TU there is no way of returning all types T with
>>> TL <: T <: TU. You can describe this set using TypeVar, but you cannot just
>>> write it down.
>>>
>>> Tommy
>>>
>>> On Wednesday, February 10, 2016 at 12:50:43 AM UTC+1, Jeffrey Sarnoff
>>> wrote:
>>>>
>>>> I see that your definition pours the subtypes from a pitcher of the
>>>> poured subtypes. The note about parametric types is well pointed. --
>>>> Jeffrey
>>>>
>>>> Clearly, the answer is therein. Cloudily, I'm looking.
>>>>
>>>>
>>>> On Tuesday, February 9, 2016 at 3:43:48 PM UTC-5, Milan Bouchet-Valat
>>>> wrote:
>>>>>
>>>>> Le mardi 09 février 2016 à 12:24 -0800, Jeffrey Sarnoff a écrit :
>>>>> > Any advice on quick 'n EZ coding of something like these?
>>>>> >
>>>>> > allsupertypes(Irrational) == ( Real, Number, Any )
>>>>> >
>>>>> > allsubtypes(Integer) == ( BigInt, Bool, Signed,
>>>>> Int128,Int16,Int32,Int64,Int8, Unsigned,
>>>>> UInt128,UInt16,UInt32,UInt64,UInt8 )
>>>>> > abstractsubtypes(Integer) == ( Signed, Unsigned )
>>>>> > concretesubtypes(Integer) == (
>>>>> BigInt,Bool,UInt128,UInt16,UInt32,UInt64,UInt8,UInt16,UInt32,UInt64,UInt8)
>>>>>
>>>>> Here's a way to get all concretes ubtypes:
>>>>> subtypestree(x) = length(subtypes(x)) > 1 ? map(subtypestree,
>>>>> subtypes(x)) : x
>>>>> [subtypestree(AbstractArray)...;]
>>>>>
>>>>> You should be able to adapt this to return all abstract types instead
>>>>> by using isleaftype() (which would better be called
>>>>> isconcretetype()?).
>>>>> But note there's the special case of parametric types, which aren't
>>>>> leaf types.
>>>>>
>>>>>
>>>>> Regards
>>>>>
>>>>
