X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Fseq.lisp;h=54c7c024620f0a83a1d46bce829a93dcc84a8dfc;hb=cee8ef591040db9a79cdd19297867672a9529051;hp=12fa57329bcddc68fe026385edcaadfc4561ce8f;hpb=768739723a84f1b7c2c1b05f79f19c8e0c602d4b;p=sbcl.git

diff --git a/src/code/seq.lisp b/src/code/seq.lisp
index 12fa573..54c7c02 100644
--- a/src/code/seq.lisp
+++ b/src/code/seq.lisp
@@ -266,6 +266,16 @@
            :type '(and list (satisfies list-length)))))
 
 
+
+(defun emptyp (sequence)
+  #!+sb-doc
+  "Returns T if SEQUENCE is an empty sequence and NIL
+   otherwise. Signals an error if SEQUENCE is not a sequence."
+  (seq-dispatch sequence
+                (null sequence)
+                (zerop (length sequence))
+                (sb!sequence:emptyp sequence)))
+
 (defun elt (sequence index)
   #!+sb-doc "Return the element of SEQUENCE specified by INDEX."
   (seq-dispatch sequence
@@ -788,24 +798,27 @@ many elements are copied."
 
 ;;;; CONCATENATE
 
-(defmacro sb!sequence:dosequence ((e sequence &optional return) &body body)
+(defmacro sb!sequence:dosequence ((element sequence &optional return) &body body)
+  #!+sb-doc
+  "Executes BODY with ELEMENT subsequently bound to each element of
+  SEQUENCE, then returns RETURN."
   (multiple-value-bind (forms decls) (parse-body body :doc-string-allowed nil)
     (let ((s sequence)
           (sequence (gensym "SEQUENCE")))
       `(block nil
         (let ((,sequence ,s))
           (seq-dispatch ,sequence
-            (dolist (,e ,sequence ,return) ,@body)
-            (do-vector-data (,e ,sequence ,return) ,@body)
+            (dolist (,element ,sequence ,return) ,@body)
+            (do-vector-data (,element ,sequence ,return) ,@body)
             (multiple-value-bind (state limit from-end step endp elt)
                 (sb!sequence:make-sequence-iterator ,sequence)
               (do ((state state (funcall step ,sequence state from-end)))
                   ((funcall endp ,sequence state limit from-end)
-                   (let ((,e nil))
+                   (let ((,element nil))
                      ,@(filter-dolist-declarations decls)
-                     ,e
+                     ,element
                      ,return))
-                (let ((,e (funcall elt ,sequence state)))
+                (let ((,element (funcall elt ,sequence state)))
                   ,@decls
                   (tagbody
                      ,@forms))))))))))
@@ -851,14 +864,10 @@ many elements are copied."
            ((eq type *empty-type*)
             (bad-sequence-type-error nil))
            ((type= type (specifier-type 'null))
-            (if (every (lambda (x) (or (null x)
-                                       (and (vectorp x) (= (length x) 0))))
-                       sequences)
-                'nil
-                (sequence-type-length-mismatch-error
-                 type
-                 ;; FIXME: circular list issues.
-                 (reduce #'+ sequences :key #'length))))
+            (unless (every #'emptyp sequences)
+              (sequence-type-length-mismatch-error
+               type (reduce #'+ sequences :key #'length))) ; FIXME: circular list issues.
+            '())
            ((cons-type-p type)
             (multiple-value-bind (min exactp)
                 (sb!kernel::cons-type-length-info type)
@@ -2180,7 +2189,8 @@ many elements are copied."
     (apply #'sb!sequence:nsubstitute-if new predicate sequence args)))
 
 (defun nlist-substitute-if* (new test sequence start end count key)
-  (declare (fixnum end))
+  (declare (type fixnum end)
+           (type function test)) ; coercion is done by caller
   (do ((list (nthcdr start sequence) (cdr list))
        (index start (1+ index)))
       ((or (= index end) (null list) (= count 0)) sequence)
@@ -2190,6 +2200,8 @@ many elements are copied."
 
 (defun nvector-substitute-if* (new test sequence incrementer
                                start end count key)
+  (declare (type fixnum end)
+           (type function test)) ; coercion is done by caller
   (do ((index start (+ index incrementer)))
       ((or (= index end) (= count 0)) sequence)
     (when (funcall test (apply-key key (aref sequence index)))
@@ -2223,7 +2235,8 @@ many elements are copied."
     (apply #'sb!sequence:nsubstitute-if-not new predicate sequence args)))
 
 (defun nlist-substitute-if-not* (new test sequence start end count key)
-  (declare (fixnum end))
+  (declare (type fixnum end)
+           (type function test)) ; coercion is done by caller
   (do ((list (nthcdr start sequence) (cdr list))
        (index start (1+ index)))
       ((or (= index end) (null list) (= count 0)) sequence)
@@ -2233,6 +2246,8 @@ many elements are copied."
 
 (defun nvector-substitute-if-not* (new test sequence incrementer
                                    start end count key)
+  (declare (type fixnum end)
+           (type function test)) ; coercion is done by caller
   (do ((index start (+ index incrementer)))
       ((or (= index end) (= count 0)) sequence)
     (when (not (funcall test (apply-key key (aref sequence index))))