Switch to more local @_

[MasonProtter]

So I realized here: JuliaLang/julia#38713 (comment) that we actually can have map(@_ 1 + _[1], v) or whatever do the right thing. Maybe this should be the canonical usage of this macro instead of being outside the map.

[mcabbott]

Oh that's pretty magical, I didn't know we could return "naked" tuples. Splat at production not consumption. Mathematica has something like this, but I thought Julia didn't.

julia> map(@_ _^2, [1 2 3])
1×3 Matrix{Int64}:
 1  4  9

julia> @macroexpand1(@_ _^2, [1 2 3])
:(((var"##x#301"->begin
              #= REPL[12]:12 =#
              var"##x#301" ^ 2
          end), [1 2 3])...)

julia> dump(ans)
Expr
  head: Symbol ...
  args: Array{Any}((1,))
    1: Expr
      head: Symbol tuple

[MasonProtter]

I feel quite silly because I've known we could do this for years, but never made the connection that it could be used to bypass JuliaLang/julia#36547

[tpapp]

Oh that's pretty magical, I didn't know we could return "naked" tuples.

Is this documented anywhere?

[MasonProtter]

Since this would be a major departure from how this package works, I think I'll close this in favour of just making a new package: https://github.com/MasonProtter/SimpleUnderscores.jl

[c42f]

Sounds good!