feat(user/elisp/remove-single-newlines.el):Add Emacs function

- Note: Useful for cleaning up Mediawiki wikicode

diff --git a/user/elisp/remove-single-newlines.el b/user/elisp/remove-single-newlines.el
new file mode 100644 (file)
index 0000000..22da713
--- /dev/null
+++ b/user/elisp/remove-single-newlines.el
@@ -0,0 +1,24 @@
+(defun remove-single-newlines ()
+  ;; Desc: Replace all single newlines with spaces.
+  ;; Date: 2024-02-24
+  "Remove single newlines, joining lines that are separated by a single newline, while preserving paragraphs separated by multiple newlines."
+  (interactive)
+  (let ((start (point-min)) (end (point-max)))
+    (save-excursion
+      (goto-char start)
+      (while (re-search-forward "\\([^\n]\\)\n\\([^\n]\\)" end t)
+        ;; Check if the newline is followed by another newline (indicating a paragraph break)
+        (unless (looking-at-p "\n")
+          (replace-match "\\1 \\2" nil nil))))))
+
+(defun remove-single-newlines-region (start end)
+  ;; Desc: Replace all single newlines in a selected region with spaces.
+  ;; Date: 2024-02-24
+  "Remove single newlines in the selected region, joining lines separated by a single newline, while preserving paragraphs separated by multiple newlines."
+  (interactive "r") ; "r" means this function should use the region start and end as arguments when called interactively
+  (save-excursion
+    (goto-char start)
+    (while (re-search-forward "\\([^\n]\\)\n\\([^\n]\\)" end t)
+      ;; Check if the newline is followed by another newline (indicating a paragraph break)
+      (unless (looking-at-p "\n")
+        (replace-match "\\1 \\2" nil nil)))))