Parametric typing in Julia is invariant, so
!(Vector{Tuple{ASCIIString,ASCIIString}} <: Vector{Tuple{String,String}})
even though
Tuple{ASCIIString,ASCIIString} <: Tuple{String,String}.
See:
http://docs.julialang.org/en/release-0.3/manual/types/#parametric-composite-types
On Tue, Aug 11, 2015 at 1:26 PM, Seth <[email protected]> wrote:
> Consider
>
> foo(a::Vector) = 1
> bar(a::Vector{Tuple}) = 2
> baz(a::Vector{Tuple{AbstractString, AbstractString}}) = 3
>
>
> foo(a::AbstractString) = foo([(a,a)])
> bar(a::AbstractString) = bar([(a,a)])
> baz(a::AbstractString) = baz([(a,a)])
>
> Results:
>
> julia> foo("a")
> 1
>
> julia> bar("a")
> ERROR: MethodError: `bar` has no method matching
> bar(::Array{Tuple{ASCIIString,ASCIIString},1})
> in bar at none:1
>
> julia> baz("a")
> ERROR: MethodError: `bar` has no method matching
> bar(::Array{Tuple{ASCIIString,ASCIIString},1})
> in baz at none:1
>
> I understand why foo() works, but why do bar() or baz() both fail?
>
