Q: How can I delete a marker after it has been created?
I see how to create markers and how to move markers, but I see nothing in the manual about how to delete them:
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1 Answer
Markers that point nowhere are garbage-collected. From the Elisp manual, node Overview of Markers:
Insertion and deletion in a buffer must check all the markers and relocate them if necessary. This slows processing in a buffer with a large number of markers. For this reason, it is a good idea to make a marker point nowhere if you are sure you don’t need it any more. Markers that can no longer be accessed are eventually removed (*note Garbage Collection::).
To make a marker point nowhere, use set-marker to set it to nil:
(set-marker my-marker nil) Is that not enough for you? Can you explain why you want to explicitly (i.e., immediately) delete a marker?
- Not original questioner but creating markers in a function calls into unknown code which could raise an error, I need to know if I should use
unwind-protectand set-marker to nil in case of failure.ideasman42– ideasman422021-10-28 00:25:05 +00:00Commented Oct 28, 2021 at 0:25 - Sorry; I don't understand what you're looking for / asking. The question, not comments, is the place to clarify it. You might want to pose a separate question, showing some code or specifying the context more clearly etc.Drew– Drew2021-10-28 04:29:25 +00:00Commented Oct 28, 2021 at 4:29
- I had the same question as the questioner, the "why" may be the same - they don't state why. I just mention if markers are created in code that might later error... this seems like a case where the script author may want to clean up - although that can be a question on it's own since I'm not sure of what's the best practice in this case.ideasman42– ideasman422021-10-28 05:55:04 +00:00Commented Oct 28, 2021 at 5:55
- Asked a related question emacs.stackexchange.com/questions/69117ideasman42– ideasman422021-10-28 06:24:57 +00:00Commented Oct 28, 2021 at 6:24