* added extension directory and extension/dynamic-root.text with

a description of the problem.

devel/ChangeLog

@@ -1,3 +1,8 @@
+2001-11-28  Gary Houston  <ghouston@arglist.com>
+
+	* added extension directory and extension/dynamic-root.text with
+	a description of the problem.
+
 2001-11-14  Thien-Thi Nguyen  <ttn@giblet.glug.org>
 
 	* policy/api.text: Initial revision.

devel/README

@@ -1,13 +0,0 @@
-Directories:
-
-policy		Guile policy documents
-
-build		Build/installation process
-
-string		Strings and characters
-
-translation	Language traslation
-
-vm		Virtual machines
-
-vm/ior		Mikael's ideas on a new type of Scheme interpreter

devel/extension/dynamic-root.text

@@ -0,0 +1,28 @@
+The Problem
+===========
+
+Certain applications embedding Guile (Scwm, Guppi) have found it
+necessary to include hacked versions of scm_call_with_dynamic_root.
+
+They want to run user callbacks, but don't want the callback to be
+able to longjmp (via exceptions or continuations) randomly in and out,
+since the C code hasn't been written to dynamically wind/unwind local
+state.  This is likely to be a common problem for users of Guile as an
+extension language.
+
+libguile/root.c:scm_call_with_dynamic_root seems to almost do this,
+but it has the apparently undesirable behaviour of unwinding the
+dynamic state when the protected procedure is called.  In addition
+the implementation looks a bit heavy for use in every callback.
+
+scm_call_with_dynamic_root was implemented to support threading, so
+the needs of libguile itself should be considered.  Other
+considerations are how any new interface interacts with error handling
+and reporting; whether a new interface is convenient to use from C;
+whether a new interface should also be available to Scheme code.
+
+Discussion
+==========
+
+Proposal
+========