chickadee » pstk


PS/Tk provides an interface to the Tk toolkit, and is an effective tool for creating graphical interfaces.


Several examples can be found in the git repository for this egg, as well as a detailed guide to using Tk from Scheme.

Hello World

(import pstk)


  (tk 'create-widget 'button 'text: "Hello" 
      'command: (lambda () (display "Hello world") (newline)))
  'padx: 20 'pady: 20)

Simple Dialog

(import pstk)

(define (celsius->fahrenheit item)
  (let ((number (string->number item)))
    (if (number? number)
      (+ (* number 9/5) 32)

(tk/wm 'title tk "Celsius to Fahrenheit")

(let* ((celsius (tk 'create-widget 'entry))
       (label (tk 'create-widget 'label))
       (button (tk 'create-widget 'button
		   'text: 'Calculate
		   'command: (lambda () 
			       (label 'configure 
				      'text: (number->string (celsius->fahrenheit (celsius 'get))))))))
  ; layout widgets in a grid
  (tk/grid celsius 'column: 2 'row: 1 'sticky: 'we 'padx: 5 'pady: 5)
  (tk/grid label 'column: 2 'row: 2 'sticky: 'we 'padx: 5 'pady: 5)
  (tk/grid button 'column: 2 'row: 3 'sticky: 'we 'padx: 5 'pady: 5)
  (tk/grid (tk 'create-widget 'label 'text: "celsius") 
	   'column: 3 'row: 1 'sticky: 'w 'padx: 5 'pady: 5)
  (tk/grid (tk 'create-widget 'label 'text: "is") 
	   'column: 1 'row: 2 'sticky: 'e 'padx: 5 'pady: 5)
  (tk/grid (tk 'create-widget 'label 'text: "fahrenheit") 
	   'column: 3 'row: 2 'sticky: 'w 'padx: 5 'pady: 5)


Tips on Using PS/Tk

(tk-start "wish85")
(tk/message-box 'title: "starting program" 'message: "Press ENTER" 'type: 'ok)
(tk-wm title tk "PROGRAM") 
  (tk-end)  ; make sure tk is closed in event of any error
  ; begin program
 ; rest of  gui setup
(tk-throw-exceptions #t)
(set! process (lambda (#!rest rest)
    (receive (a b c d) (apply process* rest)
    (values a b c))))

to your .scm file like this:

(require-extension pstk)

;; broken posix/process function under Windows 7 (MingW)
(set! process (lambda (#!rest rest)
    (receive (a b c d) (apply process* rest)
    (values a b c))))
(tk-start "tclsh85")
  (tk 'create-widget 'button 'text: "Hello" 
      'command: (lambda () (display "Hello world") (newline)))
  'padx: 20 'pady: 20)
                          '("package require Tk"
                            "fconfigure stdin -encoding utf-8"
                            "fconfigure stdout -encoding utf-8"
                            "if {[package version tile] != \"\"} {"
                            "    package require tile"

Alternatively, add the following in your script:

(tk-eval "fconfigure stdin -encoding ascii")
(tk-eval "fconfigure stdout -encoding ascii")


Kenneth A Dickey, Nils M Holm and Wolf-Dieter Busch created the initial versions of pstk. This port to Chicken, plus some additions, is by Peter Lane.



BSD 2-clause


Requires an installation of tcltk or tclkit.

Version History