How to set more than 52 marks?

Question

Possible marks are {a-zA-Z'}. Is there a mechanism to set more of them? The goal is to track certain (modifiable) lines and detect when they are deleted (e.g. with dd).

Background

I am building a UI to manipulate pairs of UUID and strings. A subset of pairs is loaded onto the buffer for editing. Only strings (on each line) are meant to be edited and UUID should be hidden. One method is to place UUID along with the string and conceal it. But UUIDs can get unintentionally deleted with concealcursor=nvic while changing the string, e.g. with cc. Marks will allow the addition, deletion and modification of string lines without losing track. Ideally, the plugin will create a mark for a line with its UUID as identifier (instead of {a-zA-Z'}).

Effectively I want to "annotate" a line with a piece of text that stays consistent after addition/deletion of lines above it and gets removed along with the line on deletion.

Answer 1

The number of marks is hard-coded in Vim, and you can't get any more without modifying the source. – Martin Tournoij

However, an advanced alternative exists in form of :h textprop in Vim and :h api-extended-marks in Neovim.

In Neovim, marks can be set using nvim_buf_set_extmark(*args) which returns unique id for the mark. E.g. Creating mark on line 0 and column 2.

let g:mark_ns = nvim_create_namespace('example')
let g:mark_id = nvim_buf_set_extmark(0, g:mark_ns, 0, 2, {})

We can get the mark by its id:

echo nvim_buf_get_extmark_by_id(0, g:mark_ns, g:mark_id)
=> [0, 2]