code.delx.au - gnu-emacs-elpa/blob - README.md

   1 # emacs-async
   2
   3 Adds the ability to process Lisp concurrently, with a very simple syntax:
   4
   5     (async-start
   6        ;; What to do in the child process
   7        (lambda ()
   8          (message "This is a test")
   9          (sleep-for 3)
  10          222)
  11
  12        ;; What to do when it finishes
  13        (lambda (result)
  14          (message "Async process done, result should be 222: %s" result)))
  15
  16 If you omit the callback function, `async-start` will return a process object
  17 that you can call `async-get` on when you're ready to wait for the result
  18 value:
  19
  20     (let ((proc (async-start
  21                    ;; What to do in the child process
  22                    (lambda ()
  23                      (message "This is a test")
  24                      (sleep-for 3)
  25                      222))))
  26         (message "I'm going to do some work here")
  27         ;; ....
  28         (message "Async process done, result should be 222: %s"
  29                  (async-get proc)))
  30
  31 If you don't want to use a callback, and you don't care about any return value
  32 form the child proces, pass the `ignore` symbol as the second argument:
  33
  34     (async-start
  35      (lambda ()
  36        (delete-file "a remote file on a slow link" nil))
  37      'ignore)