You are a life saver. This is *precisely* what we need. Thank you for
solving a very difficult problem for us. We were really pulling our hair
out after searching for a solution.
julia> module Nemo
import Base: det
abstract MatElem
function det(a::MatElem)
return 1
end
type nemomat <: MatElem
end
export nemomat
export det
end
Nemo
julia> module Hecke
using Nemo
import Nemo.det
type SpecialMat <: Nemo.MatElem
data::Int
end
function det(a::SpecialMat)
if a.data == 4
return 3
else
return invoke(det, (Nemo.MatElem,), a)
end
end
export SpecialMat
export det
end
Hecke
julia> using Hecke
julia> s = SpecialMat(3)
Hecke.SpecialMat(3)
julia> t = SpecialMat(4)
Hecke.SpecialMat(4)
julia> det(s)
1
julia> det(t)
3
Let's help search engines with this, since we were unable to find anything,
and it is such an important issue:
trouble extending a Base function in Julia
How do I call a specific version of a function in Julia for specific types
How do I call a more general version of a function in Julia
How do I call a less specific version of a function in Julia
How do I call a specific method in Julia
method to apply a function in Julia
invoking a given version of a function in Julia
To the Julia devs: please, please don't remove this functionality!
Bill.
On Tuesday, 28 June 2016 18:40:27 UTC+2, Rafael Fourquet wrote:
>
> I'm far from expert on those questions, but would the "invoke" function
> work?
> I think it's considered to be a tool of the last resort, but seems to
> be the situation you are in!
>
> invoke(f, (types...), args...)
>
> Invoke a method for the given generic function matching the
> specified types (as a tuple), on the specified arguments. The
> arguments must be compatible with
> the specified types. This allows invoking a method other than the
> most specific matching method, which is useful when the behavior of a
> more general
> definition is explicitly needed (often as part of the implementation
> of a more specific method of the same function).
>
