Don't do the first non-base definition.
On Wed, Aug 26, 2015 at 12:27 AM, Sisyphuss <[email protected]> wrote:
> This modification works, but it fails sometimes:
>
> abstract B{T}
>
> type A{T}<:B{T}
> end
>
> type C{T}<:B{T}
> end
>
> promote_rule() = 1
> promote_rule()
> @assert promote_type(A{Real},C{Real}) == B{Real}
>
> Base.promote_rule{T}(::Type{A{T}},::Type{C{T}}) = C{T}
> @assert promote_type(A{Real},C{Real}) == B{Real}
> @assert promote_type(A{Int},C{Int}) == C{Int}
>
> The behavior of `promote_rule` for the abstract parametric type is
> disrupted by the earlier weird non-Base `promote_rule`. (Environment:
> JuliaBox)
>
> By the way, why I can define `promote_rule`, but when I try to define
> `promote_type`, it raises an error?
>
>
>
>
> On Wednesday, August 26, 2015 at 5:25:50 AM UTC+2, Tim Holy wrote:
>>
>> Add `Base.` in front of `promote_rule`.
>>
>> --Tim
>>
>> On Tuesday, August 25, 2015 08:23:40 PM Sisyphuss wrote:
>> > abstract B
>> >
>> > type A<:B
>> > end
>> >
>> > type C<:B
>> > end
>> >
>> > promote_rule(::Type{A},::Type{C}) = C
>> >
>> > @assert promote_type(A,C) == B
>> >
>> > Whether I define the promotion_rule or not, the promote_type is always
>> B.
>>
>>
