quickly change indentation in spacemacs

.el

;; Put inside dotspacemacs/user-config

(defun set-tab-width (n)
  (dolist (var '(evil-shift-width
                 default-tab-width
                 tab-width
                 c-basic-offset
                 cmake-tab-width
                 coffee-tab-width
                 cperl-indent-level
                 css-indent-offset
                 elixir-smie-indent-basic
                 enh-ruby-indent-level
                 erlang-indent-level
                 javascript-indent-level
                 js-indent-level
                 js2-basic-offset
                 js3-indent-level
                 lisp-indent-offset
                 livescript-tab-width
                 mustache-basic-offset
                 nxml-child-indent
                 perl-indent-level
                 puppet-indent-level
                 python-indent-offset
                 ruby-indent-level
                 rust-indent-offset
                 scala-indent:step
                 sgml-basic-offset
                 sh-basic-offset
                 web-mode-code-indent-offset
                 web-mode-css-indent-offset
                 web-mode-markup-indent-offset))
    (set (make-local-variable var) n)))

(defun tabs (n)
  (interactive "P")
  (cond
   (n (setq n (prefix-numeric-value n)))
   ((evil-ex-p) (setq n (read evil-ex-argument)))
   (t (setq n (read-minibuffer "Indent level: "))))
  (setq-local indent-tabs-mode t)
  (set-tab-width n)
  (message "Indent level: %S" n))

(defun spaces (n)
  (interactive "P")
  (cond
   (n (setq n (prefix-numeric-value n)))
   ((evil-ex-p) (setq n (read evil-ex-argument)))
   (t (setq n (read-minibuffer "Indent level: "))))
  (setq-local indent-tabs-mode nil)
  (set-tab-width n)
  (message "Indent level: %S" n))