X-Git-Url: https://git.distorted.org.uk/~mdw/lisp/blobdiff_plain/7dcf04ad1295e4c19d0ad48b1b8cc4533cb8dd1e..67ebac1bc097d6458b82905d6289756147502f19:/mdw-base.lisp

diff --git a/mdw-base.lisp b/mdw-base.lisp
index 0b68b8d..37a3068 100644
--- a/mdw-base.lisp
+++ b/mdw-base.lisp
@@ -30,7 +30,7 @@
   (:use #:common-lisp)
   (:export #:compile-time-defun
 	   #:show
-	   #:stringify #:listify #:fix-pair #:pairify #:parse-body
+	   #:stringify #:mappend #:listify #:fix-pair #:pairify #:parse-body
 	   #:whitespace-char-p
 	   #:slot-uninitialized
 	   #:nlet #:while #:case2 #:ecase2
@@ -53,11 +53,17 @@
      (defun ,name ,args ,@body)))
 
 (defmacro show (x)
-  "Debugging tool: print the expression X and its value."
+  "Debugging tool: print the expression X and its values."
   (let ((tmp (gensym)))
-    `(let ((,tmp ,x))
-       (format t "~&~S: ~S~%" ',x ,tmp)
-       ,tmp)))
+    `(let ((,tmp (multiple-value-list ,x)))
+       (format t "~&")
+       (pprint-logical-block (*standard-output* nil :per-line-prefix ";; ")
+	 (format t
+		 "~S = ~@_~:I~:[#<no values>~;~:*~{~S~^ ~_~}~]"
+		 ',x
+		 ,tmp))
+       (terpri)
+       (values-list ,tmp))))
 
 (defun stringify (str)
   "Return a string representation of STR.  Strings are returned unchanged;
@@ -69,6 +75,12 @@
     (t (with-output-to-string (s)
 	 (princ str s)))))
 
+(defun mappend (function list &rest more-lists)
+  "Apply FUNCTION to corresponding elements of LIST and MORE-LISTS, yielding
+   a list.  Return the concatenation of all the resulting lists.  Like
+   mapcan, but nondestructive."
+  (apply #'append (apply #'mapcar function list more-lists)))
+
 (compile-time-defun listify (x)
   "If X is a (possibly empty) list, return X; otherwise return (list X)."
   (if (listp x) x (list x)))