From 8abc291f6fb9bd85c51fd1b0b7f6dce044b231a5 Mon Sep 17 00:00:00 2001
From: Yuchen Pei <hi@ypei.me>
Date: Fri, 10 Sep 2021 12:41:49 +1000
Subject: [PATCH] Add eww-{next,previous,up,top}-path.

Similar to eww-{next,previous,up,top}-url, but working based on the
url path rather than the rel attribute.

* lisp/net/eww.el (eww-next-path, eww-previous-path, eww-up-path,
eww-top-path).
* doc/misc/eww.texi TODO.
* test/lisp/net/eww-tests.el TODO.
---
 lisp/net/eww.el | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

diff --git a/lisp/net/eww.el b/lisp/net/eww.el
index 90301e92ac..ded01f97e8 100644
--- a/lisp/net/eww.el
+++ b/lisp/net/eww.el
@@ -974,6 +974,10 @@ eww-mode-map
     (define-key map "p" 'eww-previous-url)
     (define-key map "u" 'eww-up-url)
     (define-key map "t" 'eww-top-url)
+    (define-key map "N" 'eww-next-path)
+    (define-key map "P" 'eww-previous-path)
+    (define-key map "U" 'eww-up-path)
+    (define-key map "T" 'eww-top-path)
     (define-key map "&" 'eww-browse-with-external-browser)
     (define-key map "d" 'eww-download)
     (define-key map "w" 'eww-copy-page-url)
@@ -1194,6 +1198,50 @@ eww-top-url
 	(eww-browse-url (shr-expand-url best-url (plist-get eww-data :url)))
       (user-error "No `top' for this page"))))
 
+(defun eww-next-path ()
+  "Go to the `next' page according to the url path.
+The url of the `next' page is generated by incrementing the last
+number in the path."
+  (interactive)
+  (let ((url (plist-get eww-data :url)))
+    (when (string-match "^\\(.*?\\)\\([0-9]+\\)\\(.*\\)$" url)
+      (eww (concat
+	    (match-string 1 url)
+	    (number-to-string
+	     (1+ (string-to-number (match-string 2 url))))
+	    (match-string 3 url))))))
+
+(defun eww-previous-path ()
+  "Go to the `previous' page according to the url path.
+The url of the `previous' page is generated by decrementing the
+last integer in the path."
+  (interactive)
+  (let ((url (plist-get eww-data :url)))
+    (when (string-match "^\\(.*\\)\\([0-9]+\\)\\(.*\\)$" url)
+      (eww (concat
+	    (match-string 1 url)
+	    (number-to-string
+	     (1- (string-to-number (match-string 2 url))))
+	    (match-string 3 url))))))
+
+(defun eww-up-path ()
+  "Go to the `parent' page according to the url path.
+The url of the `parent' page is generated by removing the last
+segment delimited by a forward slash."
+  (interactive)
+  (let ((url (plist-get eww-data :url)))
+    (when (and (string-match "^\\(.*//.*/\\)[^/]+\\(/\\)?$" url)
+	       (match-string 1 url))
+      (eww (match-string 1 url)))))
+
+(defun eww-top-path ()
+  "Go to the domain."
+  (interactive)
+  (let ((url (plist-get eww-data :url)))
+    (when (and (string-match "^\\(.*//.*?/\\).*$" url)
+	       (match-string 1 url))
+      (eww (match-string 1 url)))))
+
 (defun eww-reload (&optional local encode)
   "Reload the current page.
 If LOCAL is non-nil (interactively, the command was invoked with
-- 
2.33.0