julia introspection - get name of variable passed to function

Question

In Julia, is there any way to get the name of a passed to a function?

x = 10
function myfunc(a)
# do something here
end
assert(myfunc(x) == "x")

Do I need to use macros or is there a native method that provides introspection?

Answer 1

You can grab the variable name with a macro:

julia> macro mymacro(arg)
           string(arg)
       end

julia> @mymacro(x)
"x"

julia> @assert(@mymacro(x) == "x")

but as others have said, I'm not sure why you'd need that.

Macros operate on the AST (code tree) during compile time, and the x is passed into the macro as the Symbol :x. You can turn a Symbol into a string and vice versa. Macros replace code with code, so the @mymacro(x) is simply pulled out and replaced with string(:x).