X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Fearly-extensions.lisp;h=6a95f383c55c6f99d70d766eb7e2ce667e0a1302;hb=15d6e7c9a2c3234f95dfe278046fa2fee1b0c007;hp=523754f0615a291b92602d5db3b507f2ce35e0eb;hpb=9767de1cecfe50560fe1da69fd458b6148a66da3;p=sbcl.git

diff --git a/src/code/early-extensions.lisp b/src/code/early-extensions.lisp
index 523754f..6a95f38 100644
--- a/src/code/early-extensions.lisp
+++ b/src/code/early-extensions.lisp
@@ -288,7 +288,12 @@
   ;; just define ASSQ explicitly in terms of more primitive
   ;; operations:
   (dolist (pair alist)
-    (when (eq (car pair) item)
+    ;; though it may look more natural to write this as 
+    ;;   (AND PAIR (EQ (CAR PAIR) ITEM))
+    ;; the temptation to do so should be resisted, as pointed out by PFD
+    ;; sbcl-devel 2003-08-16, as NIL elements are rare in association
+    ;; lists.  -- CSR, 2003-08-16
+    (when (and (eq (car pair) item) (not (null pair)))
       (return pair))))
 
 ;;; like (DELETE .. :TEST #'EQ):
@@ -365,7 +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)
@@ -793,27 +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))
@@ -824,7 +812,7 @@ which can be found at <http://sbcl.sourceforge.net/>.~:@>"
   (error 'simple-type-error ; maybe should be TYPE-BUG, subclass of BUG?
 	 :value value
 	 :expected-type type
-	 :format-string "~@<~S ~_is not a ~_~S~:>"
+	 :format-control "~@<~S ~_is not a ~_~S~:>"
 	 :format-arguments (list value type)))
 
 ;;; Return a function like FUN, but expecting its (two) arguments in
@@ -1092,6 +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)
@@ -1106,3 +1129,31 @@ 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)))