Schrodinger's deprecat

[chriselrod]

julia> module Foo
       export @m, @mdep
       macro m(ex); ex; end
       Base.@deprecate_binding var"@mdep" var"@m"
       end
Main.Foo

julia> module Bar
       using Main.Foo
       end
Main.Bar

julia> Base.isdeprecated(Main.Bar, Symbol("@mdep"))
false

julia> Base.isdeprecated(Main.Foo, Symbol("@mdep"))
true

julia> Main.Bar.var"@mdep" === Main.Foo.var"@mdep"
true

julia> Base.isdeprecated(Main.Bar, Symbol("@mdep"))
true

[chriselrod]

Note that this causes errors when running depwarn=error with Test.detect_unbound_args, which is a common thing to do when running package test suites.

[JeffBezanson]

I should write a blog post about this.

[JeffBezanson]

To try to be helpful 😄, this is due to lazy resolution of using bindings. In some sense, we don't know whether Bar.@mdep is deprecated, because we don't know whether Bar intends to use that binding. We try to avoid having predicates resolve bindings in this way.