Export remotecall_eval

[nickrobinson251]

@everywhere has (slightly surprising) behaviour for using/import statements that can best be avoided by using remotecall_eval directly, so i think remotecall_eval should be exported (or at least marked public but i think export is fine here.

Context:

The behaviour of @everywhere is that it tries to find using/import statements and run them on the calling process first, which means an @everywhere can't be defined inside a function if it contains a using/import (unless you add a hack to cause @everywhere to not find your using/import).

i.e. while this works

julia> module Foo end
Main.Foo

julia> @everywhere workers() begin
           using .Foo
       end

This fails:

julia> function f()
           @everywhere workers() begin
               using .Foo
           end
       end
ERROR: syntax: "toplevel" expression not at top level

An ugly hack to "hide" the using in a function call (lol this works):

julia> function f()
           @everywhere workers() begin
               print(using .Foo)
           end
       end
f (generic function with 1 method)

julia> f()

But a better solution is to just not use @everywhere, since this is it's documented behaviour:

  Similar to calling remotecall_eval(Main, procs, expr), but with two extra features:

    •  using and import statements run on the calling process first, to ensure packages are precompiled.

    •  The current source file path used by include is propagated to other processes.

and instead use remotecall_eval just as the docstring for @everywhere mentions, i.e.

remotecall_eval(Main, workers(), :(using .Foo))

[codecov]

Codecov Report

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[JamesWrigley]

LGTM!