(ewoc--current-dll): Remove. Basically undo the change of 2006-05-26:

use extra arguments instead of dynamic scoping.
(ewoc-locate): Remove unused var `footer'.

2 files changed, 66 insertions, 64 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 496bc1f34e2..355afbbca78 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,10 @@
+2006-05-29  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * emacs-lisp/ewoc.el (ewoc--current-dll): Remove.
+        Basically undo the change of 2006-05-26: use extra arguments instead of
+        dynamic scoping.
+        (ewoc-locate): Remove unused var `footer'.
+
 2006-05-28  Stefan Monnier  <monnier@iro.umontreal.ca>
 
         * emacs-lisp/ewoc.el (ewoc--insert-new-node): Use ewoc--refresh-node.
diff --git a/lisp/emacs-lisp/ewoc.el b/lisp/emacs-lisp/ewoc.el
index c9e2b9f27f4..b4857f4310d 100644
--- a/lisp/emacs-lisp/ewoc.el
+++ b/lisp/emacs-lisp/ewoc.el
@@ -101,44 +101,40 @@
 
 (eval-when-compile (require 'cl))
 
-;; The doubly linked list is implemented as a circular list
-;; with a dummy node first and last. The dummy node is used as
-;; "the dll" (or rather the dynamically bound `ewoc--current-dll').
-
-(defvar ewoc--current-dll)
-
+;; The doubly linked list is implemented as a circular list with a dummy
+;; node first and last. The dummy node is used as "the dll".
 (defstruct (ewoc--node
             (:type vector)              ;ewoc--node-nth needs this
             (:constructor nil)
             (:constructor ewoc--node-create (start-marker data)))
   left right data start-marker)
 
-(defun ewoc--node-next (node)
+(defun ewoc--node-next (dll node)
   "Return the node after NODE, or nil if NODE is the last node."
   (let ((R (ewoc--node-right node)))
-    (unless (eq ewoc--current-dll R) R)))
+    (unless (eq dll R) R)))
 
-(defun ewoc--node-prev (node)
+(defun ewoc--node-prev (dll node)
   "Return the node before NODE, or nil if NODE is the first node."
   (let ((L (ewoc--node-left node)))
-    (unless (eq ewoc--current-dll L) L)))
+    (unless (eq dll L) L)))
 
-(defun ewoc--node-nth (n)
-  "Return the Nth node from the doubly linked list `ewoc--current-dll'.
+(defun ewoc--node-nth (dll n)
+  "Return the Nth node from the doubly linked list `dll'.
 N counts from zero.  If N is negative, return the -(N+1)th last element.
 If N is out of range, return nil.
-Thus, (ewoc--node-nth 0) returns the first node,
-and (ewoc--node-nth -1) returns the last node."
+Thus, (ewoc--node-nth dll 0) returns the first node,
+and (ewoc--node-nth dll -1) returns the last node."
   ;; Presuming a node is ":type vector", starting with `left' and `right':
   ;; Branch 0 ("follow left pointer") is used when n is negative.
   ;; Branch 1 ("follow right pointer") is used otherwise.
   (let* ((branch (if (< n 0) 0 1))
-         (node   (aref ewoc--current-dll branch)))
+         (node   (aref dll branch)))
     (if (< n 0) (setq n (- -1 n)))
-    (while (and (not (eq ewoc--current-dll node)) (> n 0))
+    (while (and (not (eq dll node)) (> n 0))
       (setq node (aref node branch))
       (setq n (1- n)))
-    (unless (eq ewoc--current-dll node) node)))
+    (unless (eq dll node) node)))
 
 (defun ewoc-location (node)
   "Return the start location of NODE."
@@ -155,13 +151,13 @@ and (ewoc--node-nth -1) returns the last node."
 
 (defmacro ewoc--set-buffer-bind-dll-let* (ewoc varlist &rest forms)
   "Execute FORMS with ewoc--buffer selected as current buffer,
-`ewoc--current-dll' bound to the dll, and VARLIST bound as in a let*.
-`ewoc--current-dll' will be bound when VARLIST is initialized, but
+`dll' bound to the dll, and VARLIST bound as in a let*.
+`dll' will be bound when VARLIST is initialized, but
 the current buffer will *not* have been changed.
 Return value of last form in FORMS."
   (let ((hnd (make-symbol "ewoc")))
     `(let* ((,hnd ,ewoc)
-            (ewoc--current-dll (ewoc--dll ,hnd))
+            (dll (ewoc--dll ,hnd))
             ,@varlist)
        (with-current-buffer (ewoc--buffer ,hnd)
          ,@forms))))
@@ -176,7 +172,7 @@ BUT if it is the header or the footer in EWOC return nil instead."
               (eq node (ewoc--footer ewoc)))
     node))
 
-(defun ewoc--adjust (beg end node)
+(defun ewoc--adjust (beg end node dll)
   ;; "Manually reseat" markers for NODE and its successors (including footer
   ;; and dll), in the case where they originally shared start position with
   ;; BEG, to END.  BEG and END are buffer positions describing NODE's left
@@ -187,9 +183,12 @@ BUT if it is the header or the footer in EWOC return nil instead."
   (when (< beg end)
     (let (m)
       (while (and (= beg (setq m (ewoc--node-start-marker node)))
+                  ;; The "dummy" node `dll' actually holds the marker that
+                  ;; points to the end of the footer, so we check `dll'
+                  ;; *after* reseating the marker.
                   (progn
                     (set-marker m end)
-                    (not (eq ewoc--current-dll node))))
+                    (not (eq dll node))))
         (setq node (ewoc--node-right node))))))
 
 (defun ewoc--insert-new-node (node data pretty-printer)
@@ -203,10 +202,10 @@ NODE and leaving the new node's start there.  Return the new node."
             (ewoc--node-right elemnode)                  node
             (ewoc--node-right (ewoc--node-left node)) elemnode
             (ewoc--node-left                   node)  elemnode)
-      (ewoc--refresh-node pretty-printer elemnode)
+      (ewoc--refresh-node pretty-printer elemnode dll)
       elemnode)))
 
-(defun ewoc--refresh-node (pp node)
+(defun ewoc--refresh-node (pp node dll)
   "Redisplay the element represented by NODE using the pretty-printer PP."
   (let ((inhibit-read-only t)
         (m (ewoc--node-start-marker node))
@@ -216,7 +215,7 @@ NODE and leaving the new node's start there.  Return the new node."
     ;; Calculate and insert the string.
     (goto-char m)
     (funcall pp (ewoc--node-data node))
-    (ewoc--adjust m (point) R)))
+    (ewoc--adjust m (point) R dll)))
 
 (defun ewoc--wrap (func)
   (lexical-let ((ewoc--user-pp func))
@@ -284,19 +283,19 @@ fourth arg NOSEP non-nil inhibits this."
   "Enter DATA first in EWOC.
 Return the new node."
   (ewoc--set-buffer-bind-dll ewoc
-    (ewoc-enter-after ewoc (ewoc--node-nth 0) data)))
+    (ewoc-enter-after ewoc (ewoc--node-nth dll 0) data)))
 
 (defun ewoc-enter-last (ewoc data)
   "Enter DATA last in EWOC.
 Return the new node."
   (ewoc--set-buffer-bind-dll ewoc
-    (ewoc-enter-before ewoc (ewoc--node-nth -1) data)))
+    (ewoc-enter-before ewoc (ewoc--node-nth dll -1) data)))
 
 (defun ewoc-enter-after (ewoc node data)
   "Enter a new element DATA after NODE in EWOC.
 Return the new node."
   (ewoc--set-buffer-bind-dll ewoc
-    (ewoc-enter-before ewoc (ewoc--node-next node) data)))
+    (ewoc-enter-before ewoc (ewoc--node-next dll node) data)))
 
 (defun ewoc-enter-before (ewoc node data)
   "Enter a new element DATA before NODE in EWOC.
@@ -309,16 +308,14 @@ Return the new node."
 Return nil if NODE is nil or the last element."
   (when node
     (ewoc--filter-hf-nodes
-     ewoc (let ((ewoc--current-dll (ewoc--dll ewoc)))
-            (ewoc--node-next node)))))
+     ewoc (ewoc--node-next (ewoc--dll ewoc) node))))
 
 (defun ewoc-prev (ewoc node)
   "Return the node in EWOC that precedes NODE.
 Return nil if NODE is nil or the first element."
   (when node
     (ewoc--filter-hf-nodes
-     ewoc (let ((ewoc--current-dll (ewoc--dll ewoc)))
-            (ewoc--node-prev node)))))
+     ewoc (ewoc--node-prev (ewoc--dll ewoc) node))))
 
 (defun ewoc-nth (ewoc n)
   "Return the Nth node.
@@ -330,8 +327,7 @@ Use `ewoc-data' to extract the data from the node."
   ;; Skip the header (or footer, if n is negative).
   (setq n (if (< n 0) (1- n) (1+ n)))
   (ewoc--filter-hf-nodes ewoc
-                         (let ((ewoc--current-dll (ewoc--dll ewoc)))
-                           (ewoc--node-nth n))))
+                         (ewoc--node-nth (ewoc--dll ewoc) n)))
 
 (defun ewoc-map (map-function ewoc &rest args)
   "Apply MAP-FUNCTION to all elements in EWOC.
@@ -348,12 +344,12 @@ arguments will be passed to MAP-FUNCTION."
   (ewoc--set-buffer-bind-dll-let* ewoc
       ((footer (ewoc--footer ewoc))
        (pp (ewoc--pretty-printer ewoc))
-       (node (ewoc--node-nth 1)))
+       (node (ewoc--node-nth dll 1)))
     (save-excursion
       (while (not (eq node footer))
         (if (apply map-function (ewoc--node-data node) args)
-            (ewoc--refresh-node pp node))
-        (setq node (ewoc--node-next node))))))
+            (ewoc--refresh-node pp node dll))
+        (setq node (ewoc--node-next dll node))))))
 
 (defun ewoc-delete (ewoc &rest nodes)
   "Delete NODES from EWOC."
@@ -365,7 +361,7 @@ arguments will be passed to MAP-FUNCTION."
       (when (eq last node)
         (setf last nil (ewoc--last-node ewoc) nil))
       (delete-region (ewoc--node-start-marker node)
-                     (ewoc--node-start-marker (ewoc--node-next node)))
+                     (ewoc--node-start-marker (ewoc--node-next dll node)))
       (set-marker (ewoc--node-start-marker node) nil)
       (setf L (ewoc--node-left  node)
             R (ewoc--node-right node)
@@ -384,14 +380,14 @@ if it changes it.
 The PREDICATE is called with the element as its first argument.  If any
 ARGS are given they will be passed to the PREDICATE."
   (ewoc--set-buffer-bind-dll-let* ewoc
-      ((node (ewoc--node-nth 1))
+      ((node (ewoc--node-nth dll 1))
        (footer (ewoc--footer ewoc))
        (goodbye nil)
        (inhibit-read-only t))
     (while (not (eq node footer))
       (unless (apply predicate (ewoc--node-data node) args)
         (push node goodbye))
-      (setq node (ewoc--node-next node)))
+      (setq node (ewoc--node-next dll node)))
     (apply 'ewoc-delete ewoc goodbye)))
 
 (defun ewoc-locate (ewoc &optional pos guess)
@@ -403,27 +399,26 @@ If POS points before the first element, the first node is returned.
 If POS points after the last element, the last node is returned.
 If the EWOC is empty, nil is returned."
   (unless pos (setq pos (point)))
-  (ewoc--set-buffer-bind-dll-let* ewoc
-      ((footer (ewoc--footer ewoc)))
+  (ewoc--set-buffer-bind-dll ewoc
 
     (cond
      ;; Nothing present?
-     ((eq (ewoc--node-nth 1) (ewoc--node-nth -1))
+     ((eq (ewoc--node-nth dll 1) (ewoc--node-nth dll -1))
       nil)
 
      ;; Before second elem?
-     ((< pos (ewoc--node-start-marker (ewoc--node-nth 2)))
-      (ewoc--node-nth 1))
+     ((< pos (ewoc--node-start-marker (ewoc--node-nth dll 2)))
+      (ewoc--node-nth dll 1))
 
      ;; After one-before-last elem?
-     ((>= pos (ewoc--node-start-marker (ewoc--node-nth -2)))
-      (ewoc--node-nth -2))
+     ((>= pos (ewoc--node-start-marker (ewoc--node-nth dll -2)))
+      (ewoc--node-nth dll -2))
 
      ;; We now know that pos is within a elem.
      (t
       ;; Make an educated guess about which of the three known
       ;; node'es (the first, the last, or GUESS) is nearest.
-      (let* ((best-guess (ewoc--node-nth 1))
+      (let* ((best-guess (ewoc--node-nth dll 1))
              (distance (abs (- pos (ewoc--node-start-marker best-guess)))))
         (when guess
           (let ((d (abs (- pos (ewoc--node-start-marker guess)))))
@@ -431,7 +426,7 @@ If the EWOC is empty, nil is returned."
               (setq distance d)
               (setq best-guess guess))))
 
-        (let* ((g (ewoc--node-nth -1))  ;Check the last elem
+        (let* ((g (ewoc--node-nth dll -1))      ;Check the last elem
                (d (abs (- pos (ewoc--node-start-marker g)))))
           (when (< d distance)
             (setq distance d)
@@ -454,14 +449,14 @@ If the EWOC is empty, nil is returned."
               (ewoc--node-start-marker best-guess))
           ;; Loop until we are exactly one node too far down...
           (while (>= pos (ewoc--node-start-marker best-guess))
-            (setq best-guess (ewoc--node-next best-guess)))
+            (setq best-guess (ewoc--node-next dll best-guess)))
           ;; ...and return the previous node.
-          (ewoc--node-prev best-guess))
+          (ewoc--node-prev dll best-guess))
 
          ;; Pos is before best-guess
          (t
           (while (< pos (ewoc--node-start-marker best-guess))
-            (setq best-guess (ewoc--node-prev best-guess)))
+            (setq best-guess (ewoc--node-prev dll best-guess)))
           best-guess)))))))
 
 (defun ewoc-invalidate (ewoc &rest nodes)
@@ -471,7 +466,7 @@ Delete current text first, thus effecting a \"refresh\"."
       ((pp (ewoc--pretty-printer ewoc)))
     (save-excursion
       (dolist (node nodes)
-        (ewoc--refresh-node pp node)))))
+        (ewoc--refresh-node pp node dll)))))
 
 (defun ewoc-goto-prev (ewoc arg)
   "Move point to the ARGth previous element in EWOC.
@@ -485,10 +480,10 @@ Return the node we moved to."
         (setq arg (1- arg)))
       (while (and node (> arg 0))
         (setq arg (1- arg))
-        (setq node (ewoc--node-prev node)))
+        (setq node (ewoc--node-prev dll node)))
       ;; Never step above the first element.
       (unless (ewoc--filter-hf-nodes ewoc node)
-        (setq node (ewoc--node-nth 1)))
+        (setq node (ewoc--node-nth dll 1)))
       (ewoc-goto-node ewoc node))))
 
 (defun ewoc-goto-next (ewoc arg)
@@ -498,10 +493,10 @@ Return the node (or nil if we just passed the last node)."
       ((node (ewoc-locate ewoc (point))))
     (while (and node (> arg 0))
       (setq arg (1- arg))
-      (setq node (ewoc--node-next node)))
+      (setq node (ewoc--node-next dll node)))
     ;; Never step below the first element.
     ;; (unless (ewoc--filter-hf-nodes ewoc node)
-    ;;   (setq node (ewoc--node-nth -2)))
+    ;;   (setq node (ewoc--node-nth dll -2)))
     (ewoc-goto-node ewoc node)))
 
 (defun ewoc-goto-node (ewoc node)
@@ -520,15 +515,15 @@ number of elements needs to be refreshed."
   (ewoc--set-buffer-bind-dll-let* ewoc
       ((footer (ewoc--footer ewoc)))
     (let ((inhibit-read-only t))
-      (delete-region (ewoc--node-start-marker (ewoc--node-nth 1))
+      (delete-region (ewoc--node-start-marker (ewoc--node-nth dll 1))
                      (ewoc--node-start-marker footer))
       (goto-char (ewoc--node-start-marker footer))
       (let ((pp (ewoc--pretty-printer ewoc))
-            (node (ewoc--node-nth 1)))
+            (node (ewoc--node-nth dll 1)))
         (while (not (eq node footer))
           (set-marker (ewoc--node-start-marker node) (point))
           (funcall pp (ewoc--node-data node))
-          (setq node (ewoc--node-next node)))))
+          (setq node (ewoc--node-next dll node)))))
     (set-marker (ewoc--node-start-marker footer) (point))))
 
 (defun ewoc-collect (ewoc predicate &rest args)
@@ -545,12 +540,12 @@ If more than two arguments are given the
 remaining arguments will be passed to PREDICATE."
   (ewoc--set-buffer-bind-dll-let* ewoc
       ((header (ewoc--header ewoc))
-       (node (ewoc--node-nth -2))
+       (node (ewoc--node-nth dll -2))
        result)
     (while (not (eq node header))
       (if (apply predicate (ewoc--node-data node) args)
           (push (ewoc--node-data node) result))
-      (setq node (ewoc--node-prev node)))
+      (setq node (ewoc--node-prev dll node)))
     (nreverse result)))
 
 (defun ewoc-buffer (ewoc)
@@ -573,8 +568,8 @@ Return nil if the buffer has been deleted."
     (setf (ewoc--node-data head) header
           (ewoc--node-data foot) footer)
     (save-excursion
-      (ewoc--refresh-node hf-pp head)
-      (ewoc--refresh-node hf-pp foot))))
+      (ewoc--refresh-node hf-pp head dll)
+      (ewoc--refresh-node hf-pp foot dll))))
 
 
 (provide 'ewoc)