Gets extmarks in "traversal order" from a charwise region defined by buffer positions (inclusive, 0-indexed api-indexing).

Region can be given as (row,col) tuples, or valid extmark ids (whose positions define the bounds). 0 and -1 are understood as (0,0) and (-1,-1) respectively, thus the following are equivalent:

nvim_buf_get_extmarks(0, my_ns, 0, -1, {})
nvim_buf_get_extmarks(0, my_ns, [0,0], [-1,-1], {})

If end is less than start, traversal works backwards. (Useful with limit, to get the first marks prior to a given position.)

Example:

local a   = vim.api
local pos = a.nvim_win_get_cursor(0)
local ns  = a.nvim_create_namespace('my-plugin')
-- Create new extmark at line 1, column 1.
local m1  = a.nvim_buf_set_extmark(0, ns, 0, 0, {})
-- Create new extmark at line 3, column 1.
local m2  = a.nvim_buf_set_extmark(0, ns, 0, 2, {})
-- Get extmarks only from line 3.
local ms  = a.nvim_buf_get_extmarks(0, ns, {2,0}, {2,0}, {})
-- Get all marks in this buffer + namespace.
local all = a.nvim_buf_get_extmarks(0, ns, 0, -1, {})
print(vim.inspect(ms))

Parameters: {buffer} Buffer handle, or 0 for current buffer {ns_id} Namespace id from nvim_create_namespace() {start} Start of range: a 0-indexed (row, col) or valid extmark id (whose position defines the bound). api-indexing {end} End of range (inclusive): a 0-indexed (row, col) or valid extmark id (whose position defines the bound). api-indexing {opts} Optional parameters. Keys: - limit: Maximum number of marks to return - details Whether to include the details dict

Return: List of [extmark_id, row, col] tuples in "traversal order".