rant.lisp

;; Taken from Stevie's Blog Rant http://steve-yegge.blogspot.com/2008/02/portrait-of-n00b.html

(defun js2-parse-variables (in-for decl-type)
  "Parse a 'var', 'const' or 'let' statement or for-loop initializer.
IN-FOR is true if we are currently in the midst of the init clause of a for.
DECL-TYPE is a token value: either VAR, CONST, or LET depending on context.
Returns the parsed statement node."
  (let ((result (make-js2-var-decl-node))
        destructuring-init
        destructuring
        s start tt init name node
        (continue t))
    ;; Examples:
    ;; var foo = {a: 1, b: 2}, bar = [3, 4];
    ;; var {b: s2, a: s1} = foo, x = 6, y, [s3, s4] = bar;
    (while continue
      (setq destructuring nil
            s nil
            tt (js2-peek-token)
            start js2-token-start
            init nil)
      (if (or (= tt js2-LB) (= tt js2-LC))
          ;; Destructuring assignment, e.g., var [a, b] = ...
          (setq destructuring (js2-parse-primary-expr))
        ;; Simple variable name
        (js2-must-match js2-NAME "msg.bad.var")
        (setq name (make-js2-name-node))
        (js2-define-symbol decl-type js2-ts-string))
      (when (js2-match-token js2-ASSIGN)
        (setq init (js2-parse-assign-expr in-for)))
      (if destructuring
          (progn
            (if (null init)
                ;; for (var [k, v] in foo) is initialized differently
                (unless in-for
                  (js2-report-error "msg.destruct.assign.no.init")))
            (setq node (make-js2-destructuring-init-node :start start
                                                         :end js2-ts-cursor
                                                         :lhs destructuring
                                                         :initializer init))
            (js2-node-add-children node destructuring init))
        ;; simple variable, possibly with initializer
        (setq node (make-js2-var-init-node :start start
                                           :end js2-ts-cursor
                                           :name name
                                           :initializer init))
        (js2-node-add-children node name init))
      (js2-block-node-push result node)
      (js2-node-add-children result node)
      (unless (js2-match-token js2-COMMA)
        (setq continue nil)))
    result))