Concurrent ML-like concurrency for Guile
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Latest commit b86405a Aug 17, 2017


Fibers is a facility that provides Go-like concurrency for Guile Scheme, in the tradition of Concurrent ML.

A pasteable introduction to using Fibers

;; Paste this into your guile interpreter!

(use-modules (fibers) (fibers channels) (ice-9 match))

(define (server in out)
  (let lp ()
    (match (pk 'server-received (get-message in))
      ('ping! (put-message out 'pong!))
      ('sup   (put-message out 'not-much-u))
      (msg    (put-message out (cons 'wat msg))))

(define (client in out)
  (for-each (lambda (msg)
              (put-message out msg)
              (pk 'client-received (get-message in)))
            '(ping! sup)))

 (lambda ()
   (let ((c2s (make-channel))
         (s2c (make-channel)))
     (spawn-fiber (lambda () (server c2s s2c)))
     (client s2c c2s))))

If you paste the above at into a Guile REPL, it prints out:

;;; (server-received ping!)

;;; (client-received pong!)

;;; (server-received sup)

;;; (client-received not-much-u)

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Build dependencies

Guile 2.1.7 or newer (

Installation quickstart

Install from a release tarball using the standard autotools incantation:

./configure --prefix=/opt/guile && make && make install

Build from Git is the same, except run autoreconf -vif first.

You can run without installing, just run ./env guile.

Copying Fibers

Distribution of Fibers is under the LGPLv3+. See the COPYING and COPYING.LESSER files for more information.

Copying this file

Copyright (C) 2016 Free Software Foundation, Inc.

Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved.