Re: [julia-users] metaprogramming and encapsulation

[Fengyang Wang]

It is not in general possible to recover the function itself from a method, 
as methods are specific to types and not functions. Multiple functions can 
share methods if those functions have the same type.

In the case of generic (or singleton) functions, you can recover the 
function from the instance field of the type of the method's first 
parameter. That is,

first(method).sig.parameters[1].instance



On Sunday, October 2, 2016 at 11:41:12 AM UTC-4, Carlo Lucibello wrote:
>
> that could be handy indeed, thanks. 
> I would also like to automatize the process using
> ```julia
> mlist = methodswith(A, ModA)
> ```
> but looks like objects of type Method are not callable 
> ```julia
> julia> mlist[1](1)
> ERROR: MethodError: objects of type Method are not callable
>  in eval_user_input(::Any, ::Base.REPL.REPLBackend) at ./REPL.jl:64
>  in macro expansion at ./REPL.jl:95 [inlined]
>  in (::Base.REPL.##3#4{Base.REPL.REPLBackend})() at ./event.jl:68
> ```
> How do I go from a Method object to the corresponing callable Function 
> object?
>
>
> Il giorno lun 26 set 2016 alle ore 16:39 Mauro  > ha scritto:
>
>> This macro might work for you
>>
>> https://github.com/JuliaLang/DataStructures.jl/blob/8422ca9f66bfaa0f257b2bbbc8637c844d49ea68/src/delegate.jl
>>
>> On Mon, 2016-09-26 at 16:31, Carlo Lucibello > > wrote:
>> > Hi everybody,
>> > I'm looking for a metaprogramming trick to solve the following problem 
>> (I'm
>> > confident it can be done efficiently with julia) . Let's say I have 
>> defined a
>> > type in a module along with some methods:
>> > module ModA
>> > export A,f1,f2,f3
>> >
>> > type A
>> > ...
>> > end
>> >
>> > f1(a::A, x::Int) = ...
>> > f2(x, a::A, y) = ...
>> > f3(a1::A,a2::A) = ...
>> >
>> > end #module
>> > Now I have a second type that encapsulate the first
>> >
>> > using ModA
>> >
>> > type B
>> > a::A
>> > ...
>> > end
>> >
>> > and I would like to define a macro that automatically defines all the 
>> exported
>> > function in ModA for the type B in the trivial way, that is
>> >
>> > f1(b::B, x::Int) = f1(b.a, x)
>> > f2(x, b::B, y) = f1(x, b.a, y)
>> > f3(b1::B, b2::B) = f1(b1.a, b2.a)
>> >
>> > A starting point could be methodswith(A, ModA), but I don't know how to 
>> procede
>> > further. Suggestions?
>> >
>> > Bye,
>> > Carlo
>>
>

Re: [julia-users] metaprogramming and encapsulation

[Carlo Lucibello]

that could be handy indeed, thanks.
I would also like to automatize the process using
```julia
mlist = methodswith(A, ModA)
```
but looks like objects of type Method are not callable
```julia
julia> mlist[1](1)
ERROR: MethodError: objects of type Method are not callable
 in eval_user_input(::Any, ::Base.REPL.REPLBackend) at ./REPL.jl:64
 in macro expansion at ./REPL.jl:95 [inlined]
 in (::Base.REPL.##3#4{Base.REPL.REPLBackend})() at ./event.jl:68
```
How do I go from a Method object to the corresponing callable Function
object?


Il giorno lun 26 set 2016 alle ore 16:39 Mauro  ha
scritto:

> This macro might work for you
>
> https://github.com/JuliaLang/DataStructures.jl/blob/8422ca9f66bfaa0f257b2bbbc8637c844d49ea68/src/delegate.jl
>
> On Mon, 2016-09-26 at 16:31, Carlo Lucibello 
> wrote:
> > Hi everybody,
> > I'm looking for a metaprogramming trick to solve the following problem
> (I'm
> > confident it can be done efficiently with julia) . Let's say I have
> defined a
> > type in a module along with some methods:
> > module ModA
> > export A,f1,f2,f3
> >
> > type A
> > ...
> > end
> >
> > f1(a::A, x::Int) = ...
> > f2(x, a::A, y) = ...
> > f3(a1::A,a2::A) = ...
> >
> > end #module
> > Now I have a second type that encapsulate the first
> >
> > using ModA
> >
> > type B
> > a::A
> > ...
> > end
> >
> > and I would like to define a macro that automatically defines all the
> exported
> > function in ModA for the type B in the trivial way, that is
> >
> > f1(b::B, x::Int) = f1(b.a, x)
> > f2(x, b::B, y) = f1(x, b.a, y)
> > f3(b1::B, b2::B) = f1(b1.a, b2.a)
> >
> > A starting point could be methodswith(A, ModA), but I don't know how to
> procede
> > further. Suggestions?
> >
> > Bye,
> > Carlo
>

Re: [julia-users] metaprogramming and encapsulation

[Mauro]

This macro might work for you
https://github.com/JuliaLang/DataStructures.jl/blob/8422ca9f66bfaa0f257b2bbbc8637c844d49ea68/src/delegate.jl

On Mon, 2016-09-26 at 16:31, Carlo Lucibello  wrote:
> Hi everybody,
> I'm looking for a metaprogramming trick to solve the following problem (I'm
> confident it can be done efficiently with julia) . Let's say I have defined a
> type in a module along with some methods:
> module ModA
> export A,f1,f2,f3
>
> type A
> ...
> end
>
> f1(a::A, x::Int) = ...
> f2(x, a::A, y) = ...
> f3(a1::A,a2::A) = ...
>
> end #module
> Now I have a second type that encapsulate the first
>
> using ModA
>
> type B
> a::A
> ...
> end
>
> and I would like to define a macro that automatically defines all the exported
> function in ModA for the type B in the trivial way, that is
>
> f1(b::B, x::Int) = f1(b.a, x)
> f2(x, b::B, y) = f1(x, b.a, y)
> f3(b1::B, b2::B) = f1(b1.a, b2.a)
>
> A starting point could be methodswith(A, ModA), but I don't know how to 
> procede
> further. Suggestions?
>
> Bye,
> Carlo

[julia-users] metaprogramming and encapsulation

[Carlo Lucibello]

Hi everybody, 
I'm looking for a  metaprogramming trick to solve the following problem 
(I'm confident it can be done efficiently with julia) . Let's say I have 
defined a type in a module along with some methods:
module ModA
export A,f1,f2,f3

type A
...
end

f1(a::A, x::Int) = ...
f2(x, a::A, y) = ...
f3(a1::A,a2::A) = ...

end #module
Now I have a second type that encapsulate the first 

using ModA

type B
a::A
...
end

and I would like to define a macro that automatically defines all the 
exported function in ModA for the type B in the trivial way, that is

f1(b::B, x::Int) = f1(b.a, x)
f2(x, b::B, y) = f1(x, b.a, y)
f3(b1::B, b2::B) = f1(b1.a, b2.a)

A starting point could be methodswith(A, ModA), but I don't know how to 
procede further. Suggestions?

Bye,
Carlo