From abf06c1273bec1b7baf140c7b62d0c81ef10a8a5 Mon Sep 17 00:00:00 2001
From: Mikael Djurfeldt <djurfeldt@nada.kth.se>
Date: Sat, 28 Mar 1998 10:30:40 +0000
Subject: [PATCH] * boot-9.scm (remove-hook!): New macro.  (Thanks to Maciej
 Stachowiak.)

---
 ice-9/ChangeLog  | 5 +++++
 ice-9/boot-9.scm | 8 ++++++++
 2 files changed, 13 insertions(+)

diff --git a/ice-9/ChangeLog b/ice-9/ChangeLog
index da7093b8b..baeb90270 100644
--- a/ice-9/ChangeLog
+++ b/ice-9/ChangeLog
@@ -1,3 +1,8 @@
+1998-03-28  Mikael Djurfeldt  <mdj@mdj.nada.kth.se>
+
+	* boot-9.scm (remove-hook!): New macro.  (Thanks to Maciej
+	Stachowiak.)
+
 1998-01-30  Mikael Djurfeldt  <mdj@mdj.nada.kth.se>
 
 	* threads.scm: Added simple error and signal handler.
diff --git a/ice-9/boot-9.scm b/ice-9/boot-9.scm
index 1b59fae38..bef612632 100644
--- a/ice-9/boot-9.scm
+++ b/ice-9/boot-9.scm
@@ -550,6 +550,14 @@
 	     (set! ,(cadr exp)
 		   (cons thunk ,(cadr exp))))))))
 
+(define remove-hook!
+  (procedure->macro
+    (lambda (exp env)
+      `(let ((thunk ,(caddr exp)))
+	 (if (memq thunk ,(cadr exp)))
+	 (set! ,(cadr exp)
+	       (delq! thunk ,(cadr exp)))))))
+
 
 ;;; {Files}
 ;;;