Thanks for your clarification; I try to illustrate better my needs.
I like to have a /unique/ type that contains only a specified type and
that can handle any dimension, but only during object instancing (not
during subsequent lifecycle of object, also if both phases are at
runtime), than parametrized dimension (the N in AbstractArray{T,N}) is
not useful for me.
Than I should subclass AbstractArray in a similar way:
type MyArr <: AbstractArray{String}
...
end
and use this type in a similar way:
o = MyArr(number_of_dimensions::Int)
But - if I understood your indications - there is no way to do this
without redefine a bunch of methods.
At least, can I find somewhere a minimal list of these methods?
Thanks again
Leonardo
Il 10/09/2015 15:20, Matt Bauman ha scritto:
The reason you're needing to define more methods than the interface
chapter suggests is because you haven't specified the AbstractArray's
parameters; this is just as important as the required methods. That
is, you need to define your type as
type MyArr{T,N} <: AbstractArray{T,N}
in order for the interface to be properly defined. This could be
better emphasized in the interfaces chapter.
I'm not entirely sure what your needs are — could you clarify your use
case? Your wording makes it sound like you want the ability to
dynamically change the dimensionality of the array at runtime.
Unfortunately, *many* of the builtin methods for AbstractArrays
depend upon the dimensionality being defined as a type parameter… and
therefore constant for each object. Without that, you'll hit tons of
missing methods that you'll need to implement on your own (as you've
experienced).
Matt
On Thursday, September 10, 2015 at 3:06:45 AM UTC-4, Leonardo wrote:
Hi All,
I need some clarifications about subclassing AbstractArray to
create a multi-dimensional array with unspecified number of
dimensions.
I've created an (useless) example defining a simple container
(attached) to clarify me necessary step and function to implement,
and then my doubts:
* for Julia 0.4.x a chapter /Interface/
<http://docs.julialang.org/en/release-0.4/manual/interfaces/>states
that minimal function that I MUST create are size(),
getindex(), setindex!(), but in my case I MUST create another
form of getindex(), setindex!() listed between optional methods
* for Julia 0.3.x previous chapter doesn't exists, then I don't
have a clear guideline to implement my type
* running attached example (in Julia 0.3.11 64bit under Win7
64bit), other function are required to show objects in REPL
(some also undocumented like print_matrix() ), otherwise
creation of an object (e.g. with command a = MyArr(3)) fails
Than, what's correct way to subclass AbstractArray for my needs
(multidimensional array)?
Many thanks in advance for anyone can indicate me right direction
Leonardo
