Macro question (create variables)

General Usage
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5

The best practice is to only apply esc to specific parts of the returned expression which need it. So in your case, I would write your macro as

macro moo3(args...) 
    v = [:($(esc(x)) = foo($(string(x)))) for x in args]
    return Expr(:block, v...)
end

because then foo does not get escaped.

Here’s a demonstraction of why:

julia> let 
           foo(x) = x #some user locally redefines `foo(x)`
           @moo2 w1 w2
           w1, w2
       end 
("w1", "w2")

uh-oh, this isn’t the output we intended!

Now look at how @moo3 deals with this:

julia> let 
           foo(x) = x
           @moo3 w1 w2
           w1, w2
       end
("w1-w1", "w2-w2")
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