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
>>>
>>
