company and yasnippet

(defun do-yas-expand ()
  (let ((yas-fallback-behavior 'return-nil))
    (yas-expand)))

(defun check-expansion ()
  (save-excursion
    (if (looking-at "\\_>") t
      (backward-char 1)
      (if (looking-at "\\.") t
        (backward-char 1)
        (if (looking-at "->") t nil)))))

(defun tab-indent-or-complete ()
  (interactive)
  (if (minibufferp)
      (minibuffer-complete)
    (if (or (not yas-minor-mode)
            (null (do-yas-expand)))
        (if (check-expansion)
            (company-complete-common)
          (yas--fallback)))))

(define-key yas-minor-mode-map [tab] 'tab-indent-or-complete)