X-Git-Url: https://git.jsancho.org/?a=blobdiff_plain;f=gacela_misc.lisp;h=e19f3a2fe5e4aa0213ee8fd9e7710ff312109244;hb=6a3d1ffb69036e6d4f1c239fd7d52f9bfc48d50c;hp=a3991d5924d9fdd666b5c4a6d2514f60f7be371a;hpb=c0c271a74a11ccba4e5c2c51e46045c9073c32a6;p=gacela.git

diff --git a/gacela_misc.lisp b/gacela_misc.lisp
index a3991d5..e19f3a2 100755
--- a/gacela_misc.lisp
+++ b/gacela_misc.lisp
@@ -14,7 +14,11 @@
 ;;; You should have received a copy of the GNU General Public License
 ;;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-(in-package :gacela)
+
+(eval-when (compile load eval)
+	   (when (not (find-package 'gacela)) (make-package 'gacela :nicknames '(gg) :use '(lisp)))
+	   (in-package 'gacela :nicknames '(gg) :use '(lisp)))
+
 
 (defconstant INFINITY MOST-POSITIVE-LONG-FLOAT)
 
@@ -68,6 +72,38 @@
 			(t (power (* p 2) n)))))
 	  (power 1 n)))
 
+(defmacro secure-block (output-stream &rest forms)
+  (let ((error-handler #'si::universal-error-handler))
+    `(block secure
+       (defun si::universal-error-handler (error-name correctable function-name continue-format-string error-format-string &rest args)
+	 ,(when output-stream
+	    `(write-line
+	      (cond ((eq error-name :WRONG-TYPE-ARGUMENT) (string error-name))
+		    (t error-format-string))
+	      ,output-stream))
+	 (setf (symbol-function 'si::universal-error-handler) ,error-handler)
+	 (return-from secure))
+       (let (result-eval)
+	 (setq result-eval (progn ,@forms))
+	 (setf (symbol-function 'si::universal-error-handler) ,error-handler)
+	 result-eval))))
+
+(defmacro persistent-let (name vars &rest forms)
+  (labels ((get-vars (vars)
+		     (cond ((null vars) nil)
+			   (t (cons (if (consp (car vars)) (caar vars) (car vars))
+				    (get-vars (cdr vars)))))))
+   
+	  `(let ,(cond ((functionp name)
+			(let ((old-vars (funcall name)))
+			  (cond ((equal (get-vars vars) (get-vars old-vars)) old-vars)
+				(t vars))))
+		       (t vars))
+	     (defun ,name ()
+	       ,(let ((lvars (get-vars vars)))
+		  `(mapcar (lambda (x y) (list x y)) ',lvars ,(cons 'list lvars))))
+	     ,@forms)))
+
 ;Geometry
 (defun dotp (dot)
   (match-pattern dot '(0 0)))