Emacs lisp is not multi-threaded. This library explores possibilities to work around this. It allows forms to be evaluated in a different Emacs process. This means that the executed code cannot access the current environment, and the code's side effects cannot be used directly. There is a small overhead from starting a new process.
Add the following to your .emacs:
(add-to-list 'load-path "/path/to/async-eval") (require 'async-eval)
Say, you need to calculate this:
(let ((sum 0)
(i 10000000))
(while (> i 0)
(setq sum (+ sum i)
i (1- i)))
sum)
Instead of calling it directly, and blocking the Emacs interface, you can call it like this:
(async-eval
(lambda (result) (message "async result: <%s>" result))
(let ((sum 0)
(i 10000000))
(while (> i 0)
(setq sum (+ sum i)
i (1- i)))
sum))
The first argument is a function that is called with the result once the calculation is done.
Since the form is evaluated in a separate process, local functions are not available by default. If you have the following function:
(defun fib (n)
"Intentionally slow fibonacci numbers."
(if (< n 2)
n
(+ (fib (1- n)) (fib (- n 2)))))
You cannot do this, as fib won't be defined.
(async-eval
(lambda (result) (message "async result: <%s>" result))
(fib 35))
But you can conveniently export a list functions and variables to the other process:
(async-eval-with-export '(fib)
(lambda (result) (message "async result: <%s>" result))
(fib 30))
If you have any feedback, please email me, or visit this package's page at the Emacs wiki.