regex - Ruby regexp to match comma, but ignore comma in brackets -

I'm trying to divide the parameter list by regexp.

This is a string with my parameter list:

  "a = b, c = 3, d = [1,3,5,7], e, What do I want:  
  ["a = b", "c = 3", "d = [1,3, 5,7] "," E "," f = g "  
 I tried with a lookhead, but Ruby does not allow to keep an eye on a dynamic range , So this will not work:  
  / (? & Lt;! \ [], (?! \ W * \]) /   
 How to Can I tell regexp to ignore everything in square brackets?   
 
 
 Maybe something like this will work for you:  
  str.scan (/ (?: \ [ 
 would be a simple non greedy matcher.  Some cases of nested brackets Failed.