1.0.11.35: fixed bug 417

[sbcl.git] / src / code / early-extensions.lisp

diff --git a/src/code/early-extensions.lisp b/src/code/early-extensions.lisp
index 68cf7c5..9337589 100644 (file)
--- a/src/code/early-extensions.lisp
+++ b/src/code/early-extensions.lisp
@@ -377,8 +377,8 @@
 
 ;;; not really an old-fashioned function, but what the calling
 ;;; convention should've been: like NTH, but with the same argument
-;;; order as in all the other dereferencing functions, with the
-;;; collection first and the index second
+;;; order as in all the other indexed dereferencing functions, with
+;;; the collection first and the index second
 (declaim (inline nth-but-with-sane-arg-order))
 (declaim (ftype (function (list index) t) nth-but-with-sane-arg-order))
 (defun nth-but-with-sane-arg-order (list index)
@@ -395,11 +395,12 @@
 \f
 ;;;; miscellaneous iteration extensions
 
-;;; "the ultimate iteration macro"
+;;; like Scheme's named LET
 ;;;
-;;; note for Schemers: This seems to be identical to Scheme's "named LET".
+;;; (CMU CL called this ITERATE, and commented it as "the ultimate
+;;; iteration macro...". I (WHN) found the old name insufficiently
+;;; specific to remind me what the macro means, so I renamed it.)
 (defmacro named-let (name binds &body body)
-  #!+sb-doc
   (dolist (x binds)
     (unless (proper-list-of-length-p x 2)
       (error "malformed NAMED-LET variable spec: ~S" x)))
@@ -433,17 +434,24 @@
             (tagbody
                ,@forms)))))))
 
-;;; Iterate over the entries in a HASH-TABLE.
-(defmacro dohash ((key-var value-var table &optional result) &body body)
+;;; Iterate over the entries in a HASH-TABLE, first obtaining the lock
+;;; if the table is a synchronized table.
+(defmacro dohash (((key-var value-var) table &key result locked) &body body)
   (multiple-value-bind (forms decls) (parse-body body :doc-string-allowed nil)
-    (let ((gen (gensym))
-          (n-more (gensym)))
-      `(with-hash-table-iterator (,gen ,table)
-         (loop
-          (multiple-value-bind (,n-more ,key-var ,value-var) (,gen)
-            ,@decls
-            (unless ,n-more (return ,result))
-            ,@forms))))))
+    (let* ((gen (gensym))
+           (n-more (gensym))
+           (n-table (gensym))
+           (iter-form `(with-hash-table-iterator (,gen ,n-table)
+                         (loop
+                           (multiple-value-bind (,n-more ,key-var ,value-var) (,gen)
+                             ,@decls
+                             (unless ,n-more (return ,result))
+                             ,@forms)))))
+      `(let ((,n-table ,table))
+         ,(if locked
+              `(with-locked-hash-table (,n-table)
+                 ,iter-form)
+              iter-form)))))
 \f
 ;;;; hash cache utility