From 8ffbc2df0fde83082610149d24e594c1cd879f4a Mon Sep 17 00:00:00 2001
From: Bryan Newbold <bnewbold@robocracy.org>
Date: Mon, 20 Feb 2017 00:05:25 -0800
Subject: Import Upstream version 2a6

---
 dwindtst.scm | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)
 create mode 100644 dwindtst.scm

(limited to 'dwindtst.scm')

diff --git a/dwindtst.scm b/dwindtst.scm
new file mode 100644
index 0000000..8d64800
--- /dev/null
+++ b/dwindtst.scm
@@ -0,0 +1,80 @@
+;;;; "dwindtst.scm", routines for characterizing dynamic-wind.
+;Copyright (C) 1992 Aubrey Jaffer
+;
+;Permission to copy this software, to redistribute it, and to use it
+;for any purpose is granted, subject to the following restrictions and
+;understandings.
+;
+;1.  Any copy made of this software must include this copyright notice
+;in full.
+;
+;2.  I have made no warrantee or representation that the operation of
+;this software will be error-free, and I am under no obligation to
+;provide any services, by way of maintenance, update, or otherwise.
+;
+;3.  In conjunction with products arising from the use of this
+;material, there shall be no use of my name in any advertising,
+;promotional, or sales literature without prior written consent in
+;each case.
+
+(require 'dynamic-wind)
+
+(define (dwtest n)
+  (define cont #f)
+  (display "testing escape from thunk") (display n) (newline)
+  (display "visiting:") (newline)
+  (call-with-current-continuation
+   (lambda (x) (set! cont x)))
+  (if n
+      (dynamic-wind
+       (lambda ()
+	 (display "thunk1") (newline)
+	 (if (eqv? n 1) (let ((ntmp n))
+			  (set! n #f)
+			  (cont ntmp))))
+       (lambda ()
+	 (display "thunk2") (newline)
+	 (if (eqv? n 2) (let ((ntmp n))
+			  (set! n #f)
+			  (cont ntmp))))
+       (lambda ()
+	 (display "thunk3") (newline)
+	 (if (eqv? n 3) (let ((ntmp n))
+			  (set! n #f)
+			  (cont ntmp)))))))
+(define (dwctest n)
+  (define cont #f)
+  (define ccont #f)
+  (display "creating continuation thunk") (newline)
+  (display "visiting:") (newline)
+  (call-with-current-continuation
+   (lambda (x) (set! cont x)))
+  (if n (set! n (- n)))
+  (if n
+      (dynamic-wind
+       (lambda ()
+	 (display "thunk1") (newline)
+	 (if (eqv? n 1) (let ((ntmp n))
+			  (set! n #f)
+			  (cont ntmp))))
+       (lambda ()
+	 (call-with-current-continuation
+	  (lambda (x) (set! ccont x)))
+	 (display "thunk2") (newline)
+	 (if (eqv? n 2) (let ((ntmp n))
+			  (set! n #f)
+			  (cont ntmp))))
+       (lambda ()
+	 (display "thunk3") (newline)
+	 (if (eqv? n 3) (let ((ntmp n))
+			  (set! n #f)
+			  (cont ntmp))))))
+  (cond
+   (n
+    (set! n (- n))
+    (display "testing escape from continuation thunk") (display n) (newline)
+    (display "visiting:") (newline)
+    (ccont #f))))
+
+(dwtest 1) (dwtest 2) (dwtest 3)
+(dwctest 1) (dwctest 2) (dwctest 3)
-- 
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