try-catch() try-catch-finally() errors()

flan-utils.lisp

@@ -39,6 +39,26 @@
 
 ;;; --- actual (exported) code goes here --
 
+(defmacro errors (stmt)
+  `(let ((ret (handler-case (cons ,stmt nil)
+	       (t (c) (cons nil c)))))
+    (values (car ret) (cdr ret))))
+
+(defmacro try-catch (try &body catch)
+  (let ((errnm (gensym)))
+    `(let ((,errnm (handler-case (cons ,try nil)
+		     (t (e)
+			(cons (progn ,@catch) e)))))
+       (if (cdr ,errnm)
+	 (values (car ,errnm) (cdr ,errnm))
+	 (values (car ,errnm) nil)))))
+
+(defmacro try-catch-finally (try catch &body finally)
+  (let ((ret (gensym))
+	(err (gensym)))
+    `(multiple-value-bind (,ret ,err) (try-catch ,try ,catch)
+      (values (progn ,@finally) ,ret ,err))))
+
 (defmacro val-if-or (val test or)
   "(if (test val) val or)"
   `(let ((vv ,val))