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-rw-r--r--libguile/root.c39
1 files changed, 4 insertions, 35 deletions
diff --git a/libguile/root.c b/libguile/root.c
index 07209c95c..cc7a7a581 100644
--- a/libguile/root.c
+++ b/libguile/root.c
@@ -154,41 +154,10 @@ cwdr (SCM proc, SCM a1, SCM args, SCM handler, SCM_STACKITEM *stack_start)
SCM_DEFINE (scm_call_with_dynamic_root, "call-with-dynamic-root", 2, 0, 0,
(SCM thunk, SCM handler),
- "Evaluate @code{(thunk)} in a new dynamic context, returning its value.\n\n"
- "If an error occurs during evaluation, apply @var{handler} to the\n"
- "arguments to the throw, just as @code{throw} would. If this happens,\n"
- "@var{handler} is called outside the scope of the new root -- it is\n"
- "called in the same dynamic context in which\n"
- "@code{call-with-dynamic-root} was evaluated.\n\n"
- "If @var{thunk} captures a continuation, the continuation is rooted at\n"
- "the call to @var{thunk}. In particular, the call to\n"
- "@code{call-with-dynamic-root} is not captured. Therefore,\n"
- "@code{call-with-dynamic-root} always returns at most one time.\n\n"
- "Before calling @var{thunk}, the dynamic-wind chain is un-wound back to\n"
- "the root and a new chain started for @var{thunk}. Therefore, this call\n"
- "may not do what you expect:\n\n"
- "@lisp\n"
- ";; Almost certainly a bug:\n"
- "(with-output-to-port\n"
- " some-port\n\n"
- " (lambda ()\n"
- " (call-with-dynamic-root\n"
- " (lambda ()\n"
- " (display 'fnord)\n"
- " (newline))\n"
- " (lambda (errcode) errcode))))\n"
- "@end lisp\n\n"
- "The problem is, on what port will @samp{fnord} be displayed? You\n"
- "might expect that because of the @code{with-output-to-port} that\n"
- "it will be displayed on the port bound to @code{some-port}. But it\n"
- "probably won't -- before evaluating the thunk, dynamic winds are\n"
- "unwound, including those created by @code{with-output-to-port}.\n"
- "So, the standard output port will have been re-set to its default value\n"
- "before @code{display} is evaluated.\n\n"
- "(This function was added to Guile mostly to help calls to functions in C\n"
- "libraries that can not tolerate non-local exits or calls that return\n"
- "multiple times. If such functions call back to the interpreter, it should\n"
- "be under a new dynamic root.)")
+ "Call @var{thunk} with a new dynamic state and within"
+ "a continuation barrier. The @var{handler} catches all"
+ "otherwise uncaught throws and executes within the same"
+ "dynamic context as @var{thunk}.")
#define FUNC_NAME s_scm_call_with_dynamic_root
{
SCM_STACKITEM stack_place;