spacemacs/core/core-emacs-backports.el

;;; core-emacs-backports.el --- Spacemacs Core File
;;
;; Copyright (c) 2012-2016 Sylvain Benner & Contributors
;;
;; Author: Sylvain Benner <sylvain.benner@gmail.com>
;; URL: https://github.com/syl20bnr/spacemacs
;;
;; This file is not part of GNU Emacs.
;;
;;; License: GPLv3

(unless (featurep 'subr-x)
    ;; `subr-x' function for Emacs 24.3 and below
    (defsubst string-join (strings &optional separator)
      "Join all STRINGS using SEPARATOR."
      (mapconcat 'identity strings separator))

    (defsubst string-trim-left (string)
      "Remove leading whitespace from STRING."
      (if (string-match "\\`[ \t\n\r]+" string)
          (replace-match "" t t string)
        string))

    (defsubst string-trim-right (string)
      "Remove trailing whitespace from STRING."
      (if (string-match "[ \t\n\r]+\\'" string)
          (replace-match "" t t string)
        string))

    (defsubst string-trim (string)
      "Remove leading and trailing whitespace from STRING."
      (string-trim-left (string-trim-right string)))

    (defsubst string-empty-p (string)
      "Check whether STRING is empty."
      (string= string "")))

(unless (fboundp 'with-eval-after-load)
  ;; `with-eval-after-load' function for Emacs 24.3 and below
  (defmacro with-eval-after-load (file &rest body)
    "Execute BODY after FILE is loaded.
FILE is normally a feature name, but it can also be a file name,
in case that file does not provide any feature."
    (declare (indent 1) (debug t))
    `(eval-after-load ,file (lambda () ,@body))))

(provide 'core-emacs-backports)