Equivalent of `.|>` for array of functions

[koalp]

With the .|> operator, I can apply arrays of functions to arrays of values I’m new to julia but I guess that it is possible because it uses broadcast ?

functions = [(a -> a +1), (a -> a + 2)]
values = [0, 0]

r1 = values .|> functions

functions = [(a -> a +1) (a -> a + 2); (a -> a +3) (a -> a + 4)]
values = [0 0; 0 0]

r1 = values .|> functions

Is it possible to do the same with chain.jl ? I tried the @. syntax but it doesn’t work.

[filchristou]

Just started playing around with this package, so probably not the best guy to answer but:

Generally you can use the .|> by directly calling the broadcast function with . e.g.

julia> f(x) = x + 1
julia> @chain [1,2,3] f.()
3-element Vector{Int64}:
 2
 3
 4

But what you are asking is really mapping one argument to one function, and that wouldn't work in your case. You can work around that with something a little bit more verbose like:

julia> functions = [(a -> a +1) (a -> a + 2); (a -> a +3) (a -> a + 4)]
julia> values = [0 0; 0 0]
julia> @chain values map.(functions, _)
2×2 Matrix{Int64}:
 1  2
 3  4

But as mentioned above, Idk if something more explicit can be done to broadcast values by default. For me the above solution would suffice.

[jkrumbiegel]

|> is just a function with special parsing, so you can do this (even though it doesn't really serve as a great use case for Chain.jl):

julia> functions = [(a -> a +1) (a -> a + 2); (a -> a +3) (a -> a + 4)]
2×2 Matrix{Function}:
 #9   #10
 #11  #12

julia> values = [0 0; 0 0]
2×2 Matrix{Int64}:
 0  0
 0  0

julia> @chain values begin
           _ .|> functions
       end
2×2 Matrix{Int64}:
 1  2
 3  4

# or even this

julia> @chain values begin
           .|>(functions)
       end
2×2 Matrix{Int64}:
 1  2
 3  4