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)?
>>>>
>>>
