[julia-users] Problem with types used in macro from a different module!!

[Julia Tylors]

#####################
#IMPLEMENTATION CODE:
#####################

module Y
export modify

"""
A LOT OF CODE HERE, REMOVED FOR SIMPLICITY
"""

function _modify(expr)
is_lambda,f,args,body = decompose_function(expr)
if is_lambda
quote
($(args...)) -> $(transform(body))
end
else
quote
    function $(esc(f))($(args...))
      $(transform(body))
    end
end
end
end

macro modify(func)
_modify(func)
end
end

#####################
#USAGE CODE:
#####################

module X
using Y
type Arg{T}
x::T
end
println(macroexpand( quote 
@modify function f(x::Arg{Bool})
 y = 12
 if x
   y+1
 else
   y-1
end
end
end))
end

#####################
#GENERATED CODE:
#####################

begin
    begin 
        function f(#22#x::Y.Arg{Y.Bool}) 
            begin  
                #21#y = 12 # 
                begin 
                    "LOTS OF CODE HERE"
                end
            end
        end
    end
end

#########################
#QUESTION
#########################

In the generated code, the argument Arg{Bool} is treated as if it is an 
element of module Y, but it is an element of module Y. So when the code 
executes, the interpreter complains and says:
ERROR: LoadError: UndefVarError: Arg not defined

Why $(args...) in the implementation code doesn't work?

Thanks