tokenize honoring quotes

[Robert E. Griffith]

Is there an efficient native bash way to tokenize a string into an array 
honoring potentially nested double and single quotes?

For example...

   $ str='echo "hello world"'
   $ read -e -a tokens <<<"$str
   ...
   tokens[]
          [0]='echo'
          [1]='"hello'
          [2]='world"'

   In this example, I want tokens to have just two elements like...

   tokens[]
          [0]='echo'
          [1]='"hello world"'
     

I don't care much weather the quoted token retains the quotes or not.

--BobG