Check if identifier is already defined

[Eben60]

Let's assume I define in my startup file
["plot", "scatter"] => :(using Plots)
(which is what I'd actually like to do).

Then I might work with Makie in some different context. Now if I call plot in the REPL (meaning Makie.plot, with Makie already imported), Plots will be loaded, resulting in a conflict.

[LilithHafner]

Sure! You can do that with:

["plot", "scatter"] => :(isdefined(Main, :plot) || using Plots)