guile/test-suite/tests/control.test

;;;;                                                          -*- scheme -*-
;;;; control.test --- test suite for delimited continuations
;;;;
;;;; 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-control)
  #:use-module (ice-9 control)
  #:use-module (srfi srfi-11)
  #:use-module (test-suite lib))


;; For these, the compiler should be able to prove that "k" is not referenced,
;; so it avoids reifying the continuation. Since that's a slightly different
;; codepath, we test them both.
(with-test-prefix "escape-only continuations"
  (pass-if "no values, normal exit"
    (equal? '()
            (call-with-values
                (lambda ()
                  (% (values)
                     (lambda (k . args)
                       (error "unexpected exit" args))))
              list)))

  (pass-if "no values, abnormal exit"
    (equal? '()
            (% (begin
                 (abort)
                 (error "unexpected exit"))
               (lambda (k . args)
                 args))))

  (pass-if "single value, normal exit"
    (equal? '(foo)
            (call-with-values
                (lambda ()
                  (% 'foo
                     (lambda (k . args)
                       (error "unexpected exit" args))))
              list)))

  (pass-if "single value, abnormal exit"
    (equal? '(foo)
            (% (begin
                 (abort 'foo)
                 (error "unexpected exit"))
               (lambda (k . args)
                 args))))

  (pass-if "multiple values, normal exit"
    (equal? '(foo bar baz)
            (call-with-values
                (lambda ()
                  (% (values 'foo 'bar 'baz)
                     (lambda (k . args)
                       (error "unexpected exit" args))))
              list)))

  (pass-if "multiple values, abnormal exit"
    (equal? '(foo bar baz)
            (% (begin
                 (abort 'foo 'bar 'baz)
                 (error "unexpected exit"))
               (lambda (k . args)
                 args)))))

;;; And the case in which the compiler has to reify the continuation.
(with-test-prefix "reified continuations"
  (pass-if "no values, normal exit"
    (equal? '()
            (call-with-values
                (lambda ()
                  (% (values)
                     (lambda (k . args)
                       (error "unexpected exit" k args))))
              list)))

  (pass-if "no values, abnormal exit"
    (equal? '()
            (cdr
             (% (begin
                  (abort)
                  (error "unexpected exit"))
                (lambda args
                  args)))))

  (pass-if "single value, normal exit"
    (equal? '(foo)
            (call-with-values
                (lambda ()
                  (% 'foo
                     (lambda (k . args)
                       (error "unexpected exit" k args))))
              list)))

  (pass-if "single value, abnormal exit"
    (equal? '(foo)
            (cdr
             (% (begin
                  (abort 'foo)
                  (error "unexpected exit"))
                (lambda args
                  args)))))

  (pass-if "multiple values, normal exit"
    (equal? '(foo bar baz)
            (call-with-values
                (lambda ()
                  (% (values 'foo 'bar 'baz)
                     (lambda (k . args)
                       (error "unexpected exit" k args))))
              list)))

  (pass-if "multiple values, abnormal exit"
    (equal? '(foo bar baz)
            (cdr
             (% (begin
                  (abort 'foo 'bar 'baz)
                  (error "unexpected exit"))
                (lambda args
                  args))))))

;; The variants check different cases in the compiler.
(with-test-prefix "restarting partial continuations"
  (pass-if "in side-effect position"
    (let ((k (% (begin (abort) 'foo)
                (lambda (k) k))))
      (eq? (k)
           'foo)))

  (pass-if "passing values to side-effect abort"
    (let ((k (% (begin (abort) 'foo)
                (lambda (k) k))))
      (eq? (k 'qux 'baz 'hello)
           'foo)))

  (pass-if "called for one value"
    (let ((k (% (+ (abort) 3)
                (lambda (k) k))))
      (eqv? (k 39)
            42)))

  (pass-if "called for multiple values"
    (let ((k (% (let-values (((a b . c) (abort)))
                  (list a b c))
                (lambda (k) k))))
      (equal? (k 1 2 3 4)
              '(1 2 (3 4)))))

  (pass-if "in tail position"
    (let ((k (% (abort)
                (lambda (k) k))))
      (eq? (k 'xyzzy)
           'xyzzy))))

(define fl (make-fluid))
(fluid-set! fl 0)

(with-test-prefix "suspend/resume with fluids"
  (pass-if "normal"
    (zero? (% (fluid-ref fl)
              error)))
  (pass-if "with-fluids normal"
    (equal? (% (with-fluids ((fl (1+ (fluid-ref fl))))
                (fluid-ref fl))
              error)
            1))
  (pass-if "normal (post)"
    (zero? (fluid-ref fl)))
  (pass-if "with-fluids and fluid-set!"
    (equal? (% (with-fluids ((fl (1+ (fluid-ref fl))))
                 (fluid-set! fl (1+ (fluid-ref fl)))
                 (fluid-ref fl))
               error)
            2))
  (pass-if "normal (post2)"
    (zero? (fluid-ref fl)))
  (pass-if "normal fluid-set!"
    (equal? (begin
              (fluid-set! fl (1+ (fluid-ref fl)))
              (fluid-ref fl))
            1))
  (pass-if "reset fluid-set!"
    (equal? (begin
              (fluid-set! fl (1- (fluid-ref fl)))
              (fluid-ref fl))
            0))

  (let ((k (% (with-fluids ((fl (1+ (fluid-ref fl))))
                (abort)
                (fluid-ref fl))
              (lambda (k) k))))
    (pass-if "pre"
      (equal? (fluid-ref fl) 0))
    (pass-if "res"
      (equal? (k) 1))
    (pass-if "post"
      (equal? (fluid-ref fl) 0))))

(with-test-prefix "rewinding prompts"
  (pass-if "nested prompts"
    (let ((k (% 'a
                (% 'b
                   (begin
                     (abort-to-prompt 'a)
                     (abort-to-prompt 'b #t))
                   (lambda (k x) x))
                (lambda (k) k))))
      (k))))

(with-test-prefix "abort to unknown prompt"
  (pass-if-exception "foo" '(misc-error . "^Abort to unknown prompt")
                     (abort-to-prompt 'does-not-exist)))