From 60069b30d40d0db5eeba71aee1c1d0a29ba702a6 Mon Sep 17 00:00:00 2001
From: Martin Gasbichler <gasbichl@informatik.uni-tuebingen.de>
Date: Thu, 13 Feb 2003 12:05:57 +0000
Subject: [PATCH] Code from Marc Feeley's Scheme 2001 paper.

---
 .../continuation-data-type.scm                 | 18 ++++++++++++++++++
 s48/continuation-data-type/interfaces.scm      |  4 ++++
 s48/continuation-data-type/packages.scm        |  3 +++
 3 files changed, 25 insertions(+)
 create mode 100644 s48/continuation-data-type/continuation-data-type.scm
 create mode 100644 s48/continuation-data-type/interfaces.scm
 create mode 100644 s48/continuation-data-type/packages.scm

diff --git a/s48/continuation-data-type/continuation-data-type.scm b/s48/continuation-data-type/continuation-data-type.scm
new file mode 100644
index 0000000..e483334
--- /dev/null
+++ b/s48/continuation-data-type/continuation-data-type.scm
@@ -0,0 +1,18 @@
+
+;; Taken from Marc Feeley's paper "A Better API for First-Class Continunations"
+;; The version from the workshop proceedings contains a bug in continuation-capture.
+;; This is the corrected version.
+
+(define (continuation-capture receiver)
+  ((call-with-current-continuation
+    (lambda (cont)
+      (lambda () (receiver cont))))))
+
+(define (continuation-graft cont thunk)
+  (cont thunk))
+
+(define (continuation-return cont . returned-values)
+  (continuation-graft
+   cont
+   (lambda () (apply values returned-values))))
+
diff --git a/s48/continuation-data-type/interfaces.scm b/s48/continuation-data-type/interfaces.scm
new file mode 100644
index 0000000..72f14ac
--- /dev/null
+++ b/s48/continuation-data-type/interfaces.scm
@@ -0,0 +1,4 @@
+(define-interface continuation-data-type-interface
+  (export continuation-capture
+	  continuation-graft
+	  continuation-return))
diff --git a/s48/continuation-data-type/packages.scm b/s48/continuation-data-type/packages.scm
new file mode 100644
index 0000000..d6bc5a2
--- /dev/null
+++ b/s48/continuation-data-type/packages.scm
@@ -0,0 +1,3 @@
+(define-structure continuation-data-type continuation-data-type-interface
+  (open scheme)
+  (files continuation-data-type))
\ No newline at end of file