New handle* macro, analogous to catch*.

* share/txr/stdlib/except.tl (sys:expand-handle): New
function.
(handle): Use sys:expand-handle to expand arguments. The
previously unused :whole form argument is now put to use,
and correctly captured using :form rather than :whole.
(handle*): New macro.

* txr.1: Documented.

1 files changed, 15 insertions, 1 deletions

diff --git a/txr.1 b/txr.1
index 4abfebb1..d21cdbd3 100644
--- a/txr.1
+++ b/txr.1
@@ -33315,10 +33315,12 @@ exception search as if it didn't exist.  When the handler function terminates,
 either via a normal return or a nonlocal control transfer, then the handler is
 re-enabled.
 
-.coNP Macro @ handle
+.coNP Macros @ handle and @ handle*
 .synb
 .mets (handle < try-expression
 .mets \ \  >> {( symbol <> ( arg *) << body-form *)}*)
+.mets (handle* < try-expression
+.mets \ \  >> {( symbol >> ( type-arg << arg *) << body-form *)}*)
 .syne
 .desc
 The
@@ -33370,6 +33372,18 @@ via
 .code return
 or throwing an exception.
 
+The
+.code handle*
+macro is a variant of
+.code handle
+with the following difference: when
+.code handle*
+invokes a clause, it passes the exception symbol as the leftmost argument
+.metn type-arg .
+Then the exception arguments follow. In contrast,
+only the exception arguments are passed to the clauses of
+.codn handle .
+
 .coNP Macro @ with-resources
 .synb
 .mets (with-resources >> ({ sym >> [ init-form <> [ cleanup-form ])}*)