[julia-users] What is the syntax for quoting a symbol inside a quote?

[Kirill Ignatiev]

What I want to do is like this:

(let ((a (gensym)))
  (eval
   `(boundp ',a)))

and I want to construct something like

macro test()
  var = gensym("var")
  quote
    isdefined($var) ? $var += 1 : $var = 0
    @show $var
  end
end

for i=1:10; @test; end
# Desired output:
# ##var#8589 => 0
# ##var#8589 => 1
# ...

But this is wrong, because the value of var is passed to isdefined, not the 
symbol referring to it. So it's like having (eval `(boundp ,a)) in lisp. I 
can do this instead:

macro test()
  var = gensym("var")
  eval(:($var = -1))
  quote
    $var += 1
    @show $var
  end
end

but this requires me to initialize the variable at the beginning.

What is the syntax for referring to the symbol stored in a variable, not 
value of that symbol, inside a quoted expression?

Also, are there any guarantees about how long gensym's live in this case? 
Does var go into global scope?

I'm only learning Julia, and I'm slightly confused by what it expects me to 
write.