helm source for yasnippet.el
helm-c-yasnippet is available on MELPA and MELPA-STABLE.
You can install helm-c-yasnippet with the following command.
M-x package-install [RET] helm-c-yasnippet [RET]
(require 'yasnippet)
(require 'helm-c-yasnippet)
(setq helm-yas-space-match-any-greedy t)
(global-set-key (kbd "C-c y") 'helm-yas-complete)
(yas-global-mode 1)
(yas-load-directory "<path>/<to>/snippets/")