==========================================
parses regexes
==========================================
theFunction(/regex1/, /regex2/g);
---
(program (expression_statement (function_call (identifier)
    (regex) (regex))))

==========================================
parses numbers
==========================================
theFunction(100.0, 200);
---
(program (expression_statement (function_call (identifier)
    (number) (number))))

==========================================
parses strings
==========================================
theFunction('', "", 'single-quoted-string', "double-quoted-string");
---
(program (expression_statement (function_call (identifier)
    (string) (string) (string) (string))))

==========================================
parses function expressions
==========================================
var x = {
    theMethod: function(argA, argB) {
        var x = argA;
    }
};
---
(program
    (var_declaration
        (identifier)
        (object (identifier) (function_expression
            (formal_parameters (identifier) (identifier))
            (statement_block (var_declaration (identifier) (identifier)))))))

==========================================
parses comments
==========================================
// this is the beginning of the script.
// here we go.
var thing = {

    // this is a property.
    // its value is a function.
    key: function(x /* this is a parameter */) {

        // this is a statement
        doStuff();
    }
};
---
(comment)
(comment)
(program
    (var_declaration (identifier) (object
        (comment)
        (comment)
        (identifier) (function_expression
            (formal_parameters (identifier) (comment))
            (statement_block
                (comment)
                (expression_statement (function_call (identifier))))))))

==========================================
parses comments within expressions
==========================================
y // comment
  * z;
---
(program
  (expression_statement (math_op (expression (identifier) (comment)) (identifier))))
