X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Fearly-extensions.lisp;h=797f149efb79b521a8805da268dc9e91a985c09c;hb=558e7ce44e6a8305474dc55adbdbc1f7119c9a5e;hp=7435069fb9800104bb77c8ee010b48e4db7d293f;hpb=b7cfa0e5e726c2037ba2c6cb32406ff7e9764dd2;p=sbcl.git

diff --git a/src/code/early-extensions.lisp b/src/code/early-extensions.lisp
index 7435069..797f149 100644
--- a/src/code/early-extensions.lisp
+++ b/src/code/early-extensions.lisp
@@ -370,7 +370,7 @@
 
 ;;; Iterate over the entries in a HASH-TABLE.
 (defmacro dohash ((key-var value-var table &optional result) &body body)
-  (multiple-value-bind (forms decls) (parse-body body nil)
+  (multiple-value-bind (forms decls) (parse-body body :doc-string-allowed nil)
     (let ((gen (gensym))
 	  (n-more (gensym)))
       `(with-hash-table-iterator (,gen ,table)
@@ -798,27 +798,10 @@
 (defun %failed-aver (expr-as-string)
   (bug "~@<failed AVER: ~2I~_~S~:>" expr-as-string))
 
-;;; We need a definition of BUG here for the host compiler to be able
-;;; to deal with BUGs in sbcl. This should never affect an end-user,
-;;; who will pick up the definition that signals a CONDITION of
-;;; condition-class BUG; however, this is not defined on the host
-;;; lisp, but for the target. SBCL developers sometimes trigger BUGs
-;;; in their efforts, and it is useful to get the details of the BUG
-;;; rather than an undefined function error. - CSR, 2002-04-12
-#+sb-xc-host
 (defun bug (format-control &rest format-arguments)
-  (error 'simple-error
-	 :format-control "~@<  ~? ~:@_~?~:>"
-	 :format-arguments `(,format-control
-			     ,format-arguments
-			     "~@<If you see this and are an SBCL ~
-developer, then it is probable that you have made a change to the ~
-system that has broken the ability for SBCL to compile, usually by ~
-removing an assumed invariant of the system, but sometimes by making ~
-an averrance that is violated (check your code!). If you are a user, ~
-please submit a bug report to the developers' mailing list, details of ~
-which can be found at <http://sbcl.sourceforge.net/>.~:@>"
-			     ())))
+  (error 'bug
+	 :format-control format-control
+	 :format-arguments format-arguments))
 
 (defmacro enforce-type (value type)
   (once-only ((value value))
@@ -1097,6 +1080,41 @@ which can be found at <http://sbcl.sourceforge.net/>.~:@>"
                (let ((it ,test)) (declare (ignorable it)),@body)
                (acond ,@rest))))))
 
+;;; (binding* ({(names initial-value [flag])}*) body)
+;;; FLAG may be NIL or :EXIT-IF-NULL
+;;;
+;;; This form unites LET*, MULTIPLE-VALUE-BIND and AWHEN.
+(defmacro binding* ((&rest bindings) &body body)
+  (let ((bindings (reverse bindings)))
+    (loop with form = `(progn ,@body)
+          for binding in bindings
+          do (destructuring-bind (names initial-value &optional flag)
+                 binding
+               (multiple-value-bind (names declarations)
+                   (etypecase names
+                     (null
+                      (let ((name (gensym)))
+                        (values (list name) `((declare (ignorable ,name))))))
+                     (symbol
+                      (values (list names) nil))
+                     (list
+                      (collect ((new-names) (ignorable))
+                        (dolist (name names)
+                          (when (eq name nil)
+                            (setq name (gensym))
+                            (ignorable name))
+                          (new-names name))
+                        (values (new-names)
+                                (when (ignorable)
+                                  `((declare (ignorable ,@(ignorable)))))))))
+                 (setq form `(multiple-value-bind ,names
+                                 ,initial-value
+                               ,@declarations
+                               ,(ecase flag
+                                       ((nil) form)
+                                       ((:exit-if-null)
+                                        `(when ,(first names) ,form)))))))
+          finally (return form))))
 
 ;;; Delayed evaluation
 (defmacro delay (form)
@@ -1111,3 +1129,45 @@ which can be found at <http://sbcl.sourceforge.net/>.~:@>"
 (defun promise-ready-p (promise)
   (or (not (consp promise))
       (car promise)))
+
+;;; toplevel helper
+(defmacro with-rebound-io-syntax (&body body)
+  `(%with-rebound-io-syntax (lambda () ,@body)))
+
+(defun %with-rebound-io-syntax (function)
+  (declare (type function function))
+  (let ((*package* *package*)
+	(*print-array* *print-array*)
+	(*print-base* *print-base*)
+	(*print-case* *print-case*)
+	(*print-circle* *print-circle*)
+	(*print-escape* *print-escape*)
+	(*print-gensym* *print-gensym*)
+	(*print-length* *print-length*)
+	(*print-level* *print-level*)
+	(*print-lines* *print-lines*)
+	(*print-miser-width* *print-miser-width*)
+	(*print-pretty* *print-pretty*)
+	(*print-radix* *print-radix*)
+	(*print-readably* *print-readably*)
+	(*print-right-margin* *print-right-margin*)
+	(*read-base* *read-base*)
+	(*read-default-float-format* *read-default-float-format*)
+	(*read-eval* *read-eval*)
+	(*read-suppress* *read-suppress*)
+	(*readtable* *readtable*))
+    (funcall function)))
+
+;;; Bind a few "potentially dangerous" printer control variables to
+;;; safe values, respecting current values if possible.
+(defmacro with-sane-io-syntax (&body forms)
+  `(call-with-sane-io-syntax (lambda () ,@forms)))
+
+(defun call-with-sane-io-syntax (function)
+  (declare (type function function))
+  (macrolet ((true (sym)
+               `(and (boundp ',sym) ,sym)))
+    (let ((*print-readably* nil)
+          (*print-level* (or (true *print-level*) 6))
+          (*print-length* (or (true *print-length*) 12)))
+      (funcall function))))