guile/test-suite/tests/fluids.test

;;;;                                                          -*- scheme -*-
;;;; fluids.test --- test suite for fluid values
;;;;
;;;; Copyright (C) 2010 Free Software Foundation, Inc.
;;;; 
;;;; This library is free software; you can redistribute it and/or
;;;; modify it under the terms of the GNU Lesser General Public
;;;; License as published by the Free Software Foundation; either
;;;; version 3 of the License, or (at your option) any later version.
;;;; 
;;;; This library is distributed in the hope that it will be useful,
;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
;;;; Lesser General Public License for more details.
;;;; 
;;;; You should have received a copy of the GNU Lesser General Public
;;;; License along with this library; if not, write to the Free Software
;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

(define-module (test-suite test-fluids)
  :use-module (test-suite lib)
  :use-module (system base compile))


(define exception:syntax-error
  (cons 'syntax-error "failed to match"))
(define exception:duplicate-binding
  (cons 'syntax-error "duplicate"))

(define a (make-fluid))
(define b (make-fluid))
(define c #f)

(with-test-prefix "syntax"
  (pass-if-exception "with-fluids missing expression"
    exception:syntax-error
    (eval '(with-fluids ((a 1)))
	  (interaction-environment)))

  (pass-if-exception "with-fluids bad bindings"
    exception:syntax-error
    (eval '(with-fluids (a) #f)
	  (interaction-environment)))

  (pass-if-exception "with-fluids bad bindings"
    exception:syntax-error
    (eval '(with-fluids ((a)) #f)
	  (interaction-environment))))

(with-test-prefix "initial fluid values"
  (pass-if "fluid-ref uninitialized fluid is #f"
    (not (fluid-ref a)))

  (pass-if "initial value is inherited from parent thread"
    (if (provided? 'threads)
        (let ((f (make-fluid)))
          (fluid-set! f 'initial)
          (let ((child (call-with-new-thread
                        (lambda ()
                          (let ((init (fluid-ref f)))
                            (fluid-set! f 'new)
                            (list init (fluid-ref f)))))))
            (equal? '(initial new) (join-thread child))))
        (throw 'unresolved))))

(with-test-prefix "with-fluids with non-fluid"
  (pass-if-exception "exception raised if nonfluid passed to with-fluids"
                     exception:wrong-type-arg
    (with-fluids ((c #t))
      c))
  
  (pass-if "fluids not modified if nonfluid passed to with-fluids"
    (catch 'wrong-type-arg
      (lambda ()
        (with-fluids ((a #t)
                      (c #t))
          #f))
      (lambda _
        (not (fluid-ref a))))))

(with-test-prefix "with-fluids with duplicate fluid"
  ;; These tests must be compiled, because the evaluator
  ;; effectively transforms (with-fluids ((a 1) (b 2)) ...)
  ;; into (with-fluids ((a 1)) (with-fluids ((b 2)) ...))

  (pass-if "last value wins"
    (compile '(with-fluids ((a 1)
                            (a 2)
                            (a 3))
                (eqv? (fluid-ref a) 3))
             #:env (current-module)))
  
  (pass-if "remove the duplicate, not the last binding"
    (compile '(with-fluids ((a 1)
                            (a 2)
                            (a 3)
                            (b 4))
                (eqv? (fluid-ref b) 4))
             #:env (current-module)))

  (pass-if "original value restored"
    (compile '(and (with-fluids ((a 1)
                                 (a 2))
                     (eqv? (fluid-ref a) 2))
                   (eqv? (fluid-ref a) #f))
             #:env (current-module))))

(pass-if "fluid values are thread-local"
  (if (provided? 'threads)
      (let ((f (make-fluid)))
        (fluid-set! f 'parent)
        (let ((child (call-with-new-thread
                      (lambda ()
                        (fluid-set! f 'child)
                        (fluid-ref f)))))
          (and (eq? (join-thread child) 'child)
               (eq? (fluid-ref f) 'parent))))
      (throw 'unresolved)))

(pass-if "fluids are GC'd"

  (let ((g (make-guardian)))
    (g (make-fluid))
    (let loop ((i 1000))
      (and (> i 0)
           (begin
             (make-fluid)
             (loop (1- i)))))
    (gc)
    (fluid? (g))))

(with-test-prefix "with-fluids"

  (pass-if "with-fluids binds"
    (= (with-fluids ((a 1)) (fluid-ref a)) 1))

  (pass-if "with-fluids unbinds"
    (begin
      (fluid-set! a 0)
      (with-fluids ((a 1)) (fluid-ref a))
      (= (fluid-ref a) 0)))
  
  (pass-if "with-fluids and dynamic-wind"
    (letrec ((co-routine #f)
	     (spawn (lambda (proc)
		      (set! co-routine proc)))
	     (yield (lambda (val)
		      (call-with-current-continuation
		       (lambda (k)
			 (let ((next co-routine))
			   (set! co-routine k)
			   (next val)))))))
      
      (spawn (lambda (val)
	       (with-fluids ((a 'inside))
	         (yield (fluid-ref a))
		 (yield (fluid-ref a)))))

      (fluid-set! a 'outside)
      (let ((inside-a (yield #f)))
	(let ((outside-a (fluid-ref a)))
	  (let ((inside-a2 (yield #f)))
	    (and (eq? inside-a 'inside)
		 (eq? outside-a 'outside)
		 (eq? inside-a2 'inside))))))))

(with-test-prefix "unbound fluids"
  (pass-if "fluid-ref of unbound fluid"
    (catch #t
           (lambda () (fluid-ref (make-unbound-fluid)))
           (lambda (key . args) #t)))
  (pass-if "fluid-bound? of bound fluid"
    (fluid-bound? (make-fluid)))
  (pass-if "fluid-bound? of unbound fluid"
    (not (fluid-bound? (make-unbound-fluid))))
  (pass-if "unbound fluids can be set"
    (let ((fluid (make-unbound-fluid)))
      (fluid-set! fluid #t)
      (fluid-ref fluid)))
  (pass-if "bound fluids can be unset"
    (let ((fluid (make-fluid)))
      (fluid-unset! fluid)
      (catch #t
             (lambda () (fluid-ref fluid))
             (lambda (key . args) #t)))))