Not all tokens are returned as an array. The rule appears to be that if a token is not variable, but instead it is one particular constant string, it is returned as a string instead. You don't get a line number. This is the case for braces( "{", "}"), parentheses ("(", ")"), brackets ("[", "]"), comma (","), semi-colon (";"), and a whole slew of operator signs ("!", "=", "+", "*", "/", ".", "+=", ...).