Ruby - convert from symbol to variable

Question

How can I convert :obj back into a variable called obj inside the def?

def foo(bar)
  bar.some_method_call
end

foo :obj

UPDATE: The final code is more elaborate than this but...

I like to be able to say

foo :obj  

instead of

foo obj  

I working on some DSL-like syntax. And this one change would let things read a little clearer.

Answer 1

What kind of variable is obj in your example? If it's a local variable of the scope where foo is called, it can't be accessed from inside foo, unless you pass the current binding as a second parameter.

If you want to access the instance variable @obj, it's easy:

def foo(bar)
  instance_variable_get("@#{bar}").length
end

@obj = "lala"
foo("obj") #=> 4

Answer 2

You could use eval

def foo(bar)
  eval(bar.to_s).some_method_call
end