branch: externals/denote-sequence
commit 7040e4cb6706c7a3023b1712ac94f83b448daffe
Author: Protesilaos Stavrou <i...@protesilaos.com>
Commit: Protesilaos Stavrou <i...@protesilaos.com>
Define function to infer a sibling and write a test for it as well
---
denote-sequence.el | 17 +++++++++++++++++
tests/denote-sequence-test.el | 14 ++++++++++++++
2 files changed, 31 insertions(+)
diff --git a/denote-sequence.el b/denote-sequence.el
index dadb169243..20ce224d6b 100644
--- a/denote-sequence.el
+++ b/denote-sequence.el
@@ -393,6 +393,23 @@ depth given SEQUENCE."
(t (error "Unknown type of sequence for `%s'"
last-component)))))
(denote-sequence-join (list sequence new-depth) scheme)))
+(defun denote-sequence--infer-sibling (sequence direction)
+ "Get sibling of SEQUENCE in DIRECTION `next' or `previous'.
+Do not actually try to create a new sibling nor to test for the
+existence of one. Simply do the work of finding the next or previous
+sibling in the sequence."
+ (pcase-let* ((`(,sequence . ,scheme) (denote-sequence-and-scheme-p sequence))
+ (components (denote-sequence-split sequence))
+ (butlast (butlast components))
+ (last-component (car (nreverse components)))
+ (direction-fn (pcase direction
+ ('next #'denote-sequence-increment-partial)
+ ('previous #'denote-sequence-decrement-partial)
+ (_ (error "Unknown DIRECTION `%s'" direction))))
+ (new-number (funcall direction-fn last-component)))
+ (when new-number
+ (denote-sequence-join (append butlast (list new-number)) scheme))))
+
(defun denote-sequence--get-files (&optional files)
"Return list of files or buffers in the variable `denote-directory'.
With optional FILES only consider those, otherwise use
`denote-directory-files'."
diff --git a/tests/denote-sequence-test.el b/tests/denote-sequence-test.el
index de5bb2c3a5..29abcd78df 100644
--- a/tests/denote-sequence-test.el
+++ b/tests/denote-sequence-test.el
@@ -245,6 +245,20 @@ function `denote-sequence-get-relative'."
(should (string= (denote-sequence-decrement-partial "bbcza") "bbcz"))
(should-error (denote-sequence-decrement-partial "1a")))
+(ert-deftest dst-denote-sequence--infer-sibling ()
+ "Test that `denote-sequence--infer-sibling' returns the correct result."
+ (should (string= (denote-sequence--infer-sibling "1" 'next) "2"))
+ (should (string= (denote-sequence--infer-sibling "1a" 'next) "1b"))
+ (should (string= (denote-sequence--infer-sibling "1z" 'next) "1za"))
+ (should (string= (denote-sequence--infer-sibling "1=1" 'next) "1=2"))
+ (should (string= (denote-sequence--infer-sibling "2" 'previous) "1"))
+ (should (string= (denote-sequence--infer-sibling "1b" 'previous) "1a"))
+ (should (string= (denote-sequence--infer-sibling "1za" 'previous) "1z"))
+ (should (string= (denote-sequence--infer-sibling "1=2" 'previous) "1=1"))
+ (should (null (denote-sequence--infer-sibling "1" 'previous)))
+ (should (null (denote-sequence--infer-sibling "1=1" 'previous)))
+ (should (null (denote-sequence--infer-sibling "1a" 'previous))))
+
(provide 'denote-sequence-test)
;;; denote-sequence-test.el ends here
