Also note that it's specific to parameterised types.
julia> dispatchtest2(x::Union{Array{Int64,1},Int64}) = "success"
dispatchtest2 (generic function with 2 methods)
julia> dispatchtest2([1,2])
"success"
On Wednesday, 21 October 2015 00:09:42 UTC+10, Glen O wrote:
>
> Seems to be something wrong with the dispatch system with Union...
>
> julia> dispatchtest{T}(x::Union{Array{T,1},T}) = "success"
> dispatchtest (generic function with 3 methods)
>
> julia> dispatchtest([1,2])
> ERROR: MethodError: `dispatchtest` has no method matching
> dispatchtest(::Array{Int64,1})
>
>
>
> On Tuesday, 20 October 2015 22:05:31 UTC+10, Kristoffer Carlsson wrote:
>>
>> Not sure why it doesn't work when the array comes first:
>>
>>
>> julia> dispatchtest(2,[1,2])
>> "success"
>>
>> julia> dispatchtest(2,[1,2],2)
>> "success"
>>
>> julia> dispatchtest(2,[1,2],2,[1,2])
>> "success"
>>
>> julia> dispatchtest([1,2],2,[1,2],2,[1,2])
>> ERROR: MethodError: `dispatchtest` has no method matching dispatchtest(::
>> Array{Int64,1}, ::Int64, ::Array{Int64,1}, ::Int64, ::Array{Int64,1})
>> Closest candidates are:
>> dispatchtest{T}(::Union{Array{T,1},T}...)
>> dispatchtest{T}(::Union{Array{T,1},T}...)
>>
>>
>>
>>
>>
>>
>> On Tuesday, October 20, 2015 at 1:33:37 PM UTC+2, Andras Niedermayer
>> wrote:
>>>
>>> This doesn't work:
>>> dispatchtest{T}(x::Vararg{Union{T,Array{T,1}}}) = "success"
>>> dispatchtest([1,2],3)
>>>
>>>
>>> results in
>>>
>>> LoadError: MethodError: `dispatchtest` has no method matching
>>> dispatchtest(::Array{Int64,1}, ::Int64)
>>> Closest candidates are:
>>> dispatchtest{T}(!Matched::Union{Array{T,1},T}...)
>>> while loading In[8], in expression starting on line 1
>>>
>>>
>>>
>>> On Tuesday, October 20, 2015 at 1:19:24 PM UTC+2, Kristoffer Carlsson
>>> wrote:
>>>>
>>>> Try: Base.vcat{T}(x::Vararg{Union{T,Array{T,1}}}) = mixed_vcat(x...)
>>>>
>>>> On Tuesday, October 20, 2015 at 11:44:15 AM UTC+2, Andras Niedermayer
>>>> wrote:
>>>>>
>>>>> I've written an implementation of vcat for the special case of mixed
>>>>> scalar-vector parameters (e.g. vcat(1,[2,3],4)) using generated
>>>>> functions.
>>>>> I get a speed increase of a factor 70 and memory usage reduction by a
>>>>> factor 10. It also makes this special case of vcat type stable (e.g. the
>>>>> inferred type is Array{Int64,1} rather than Any for vcat(1,[2,3],4)). See
>>>>> https://gist.github.com/afniedermayer/947faadd362778d088d7
>>>>>
>>>>> I'd like to make a pull request (or at least provide a package that
>>>>> overloads vcat to start with), but I haven't figured out how to dispatch
>>>>> on
>>>>> mixed scalar-vector parameters.
>>>>> Base.vcat{T}(x::Union{T,Array{T,1}}...) = mixed_vcat(x...)
>>>>>
>>>>>
>>>>> doesn't work, see
>>>>> https://groups.google.com/forum/#!topic/julia-users/NCfxu7_9VR0
>>>>>
>>>>> Is there a way to dispatch on mixed scalar-vector parameters (besides
>>>>> dispatching in the generated function)?
>>>>>
>>>>
