TinyWM in Chicken Scheme

gistfile1.scm

;; TinyWM is written by Nick Welch <mack@incise.org>, 2005.
;; Ported to Chicken by César L. B. Silveira <cesarbs@gmail.com>, 2011.
;;
;; Original TinyWM website: http://incise.org/tinywm.html
;;
;; This software is in the public domain
;; and is provided AS IS, with NO WARRANTY.

(require-extension xlib)

(let* ((dpy (xopendisplay #f))
       (root (xdefaultrootwindow dpy))
       (attr (make-xwindowattributes))
       (start-button 0)
       (start-x 0)
       (start-y 0)
       (ev (make-xevent)))
  (xgrabkey dpy
            (char->integer (xkeysymtokeycode dpy (xstringtokeysym "F1")))
            MOD1MASK
            root
            1
            GRABMODEASYNC
            GRABMODEASYNC)
  (xgrabbutton dpy
               BUTTON1
               MOD1MASK
               root
               1
               BUTTONPRESSMASK
               GRABMODEASYNC
               GRABMODEASYNC
               NONE
               NONE)
  (xgrabbutton dpy
               BUTTON3
               MOD1MASK
               root
               1
               BUTTONPRESSMASK
               GRABMODEASYNC
               GRABMODEASYNC
               NONE
               NONE)
  (let loop ()
    (xnextevent dpy ev)
    (cond ((and (equal? (xevent-type ev) KEYPRESS)
                (not (equal? (xkeyevent-subwindow ev) NONE)))
           (xraisewindow dpy (xkeyevent-subwindow ev)))
          ((and (equal? (xevent-type ev) BUTTONPRESS)
                (not (equal? (xbuttonevent-subwindow ev) NONE)))
           (xgrabpointer dpy
                         (xbuttonevent-subwindow ev)
                         1
                         (bitwise-ior POINTERMOTIONMASK BUTTONRELEASEMASK)
                         GRABMODEASYNC
                         GRABMODEASYNC
                         NONE
                         NONE
                         CURRENTTIME)
           (xgetwindowattributes dpy (xbuttonevent-subwindow ev) attr)
           (set! start-button (xbuttonevent-button ev))
           (set! start-x (xbuttonevent-x_root ev))
           (set! start-y (xbuttonevent-y_root ev)))
          ((equal? (xevent-type ev) MOTIONNOTIFY)
           (let ((xdiff (- (xmotionevent-x_root ev) start-x))
                 (ydiff (- (xmotionevent-y_root ev) start-y)))
             (xmoveresizewindow
              dpy
              (xmotionevent-window ev)
              (+ (xwindowattributes-x attr)
                 (if (equal? start-button BUTTON1) xdiff 0))
              (+ (xwindowattributes-y attr)
                 (if (equal? start-button BUTTON1) ydiff 0))
              (max 1 (+ (xwindowattributes-width attr)
                        (if (equal? start-button BUTTON3) xdiff 0)))
              (max 1 (+ (xwindowattributes-height attr)
                        (if (equal? start-button BUTTON3) ydiff 0))))))
          ((equal? (xevent-type ev) BUTTONRELEASE)
           (xungrabpointer dpy CURRENTTIME)))
    (loop)))

Thanks, I was looking for something like this.