telescope results line color / highlight

[sand4rt]

Is your feature request related to a problem? Please describe.
The ability to change the color of the line next to the line numbers (the red one in the screenshot) without effecting the normal text.

Describe the solution you'd like
A new highlight group to change the color.

Describe alternatives you've considered
I changed TelescopeResultsNormal, but that also affects other text.

Additional context

[jamestrew]

There technically is a separator_hl option deep inside the results entry creation mechanism that you could take advantage of but it's pretty inaccessible at the moment and none of the builtin pickers utilize it so I'm an agreement that it's probably better to just have a hl group for the separator.

But this is pretty low priority for me personally. If someone wants to have a go at it, I'd be willing to offer some help.

[MovieMaker93]

@jamestrew, do you mean this piece of code?:

By creating a new hl_group, do you mean to make it and add it as default like the others?
Also, how did you configure the line next to the number? By default, I have only the line number and not the separator @sand4rt

[jamestrew]

@MovieMaker93 that's right.

telescope.nvim/lua/telescope/make_entry.lua

Lines 925 to 932 in 5665d93

	function make_entry.gen_from_buffer_lines(opts)
	local displayer = entry_display.create {
	separator = " │ ",
	items = {
	{ width = 5 },
	{ remaining = true },
	},
	}

We could technically make current_buffer_fuzzy_find and other pickers using entry_display take a separator_hl option but I feel like just adding a new hl group, something like TelescopeResultsSeparator would be a cleaner way.

[MovieMaker93]

@MovieMaker93 that's right.

telescope.nvim/lua/telescope/make_entry.lua

Lines 925 to 932 in 5665d93

	function make_entry.gen_from_buffer_lines(opts)
	local displayer = entry_display.create {
	separator = " │ ",
	items = {
	{ width = 5 },
	{ remaining = true },
	},
	}

We could technically make current_buffer_fuzzy_find and other pickers using entry_display take a separator_hl option, but I feel like just adding a new hl group, something like TelescopeResultsSeparator would be a cleaner way.

Thanks for the answer. I'm trying to understand how the highlighters work for the pickers, but I haven't fully grasped it yet.
I've added the new hlgroup here:

telescope.nvim/lua/telescope/pickers.lua

Lines 73 to 84 in 5665d93

	local popup_opts = picker:get_window_options(vim.o.columns, line_count)
	-- `popup.nvim` massaging so people don't have to remember minheight shenanigans
	popup_opts.results.focusable = true
	popup_opts.results.minheight = popup_opts.results.height
	popup_opts.results.highlight = "TelescopeResultsNormal"
	popup_opts.results.borderhighlight = "TelescopeResultsBorder"
	popup_opts.results.titlehighlight = "TelescopeResultsTitle"
	popup_opts.prompt.minheight = popup_opts.prompt.height
	popup_opts.prompt.highlight = "TelescopePromptNormal"
	popup_opts.prompt.borderhighlight = "TelescopePromptBorder"
	popup_opts.prompt.titlehighlight = "TelescopePromptTitle"

and as default here:

telescope.nvim/plugin/telescope.lua

Lines 18 to 22 in 5665d93

	-- "Normal" in the floating windows created by telescope.
	TelescopeNormal = { default = true, link = "Normal" },
	TelescopePreviewNormal = { default = true, link = "TelescopeNormal" },
	TelescopePromptNormal = { default = true, link = "TelescopeNormal" },
	TelescopeResultsNormal = { default = true, link = "TelescopeNormal" },

However, I don't know where to specify this hlgroup option. I didn't understand where the popup_opts has been defined or how to define the new hlgroup besides the one place specified above.
Could you guide me further on how to do it?

[jamestrew]

On second thought, maybe TelescopeResultsEntrySeparator might be clearer.

However, I don't know where to specify this hlgroup option.

I think you could just do something like

configuration.separator_hl = vim.F.if_nil(configuration.separator_hl, "TelescopeResultsEntrySeparator")

at the top of the entry_display.create function. This should add the highlight group to a table of highlights for the entry.
The actual setting of the entry highlights happens closer to here:

telescope.nvim/lua/telescope/pickers.lua

Lines 1264 to 1300 in c2ce039

	local display, display_highlights = entry_display.resolve(self, entry)
	if not display then
	log.info("Weird entry", entry)
	return
	end
	-- This is the two spaces to manage the '> ' stuff.
	-- Maybe someday we can use extmarks or floaty text or something to draw this and not insert here.
	-- until then, insert two spaces
	local prefix = self.entry_prefix
	display = prefix .. display
	self:_increment "displayed"
	local offset = insert and 0 or 1
	if not vim.api.nvim_buf_is_valid(self.results_bufnr) then
	log.debug "ON_ENTRY: Invalid buffer"
	return
	end
	-- TODO: Does this every get called?
	-- local line_count = vim.api.nvim_win_get_height(self.results_win)
	local line_count = vim.api.nvim_buf_line_count(self.results_bufnr)
	if row > line_count then
	return
	end
	if insert then
	if self.sorting_strategy == "descending" then
	vim.api.nvim_buf_set_lines(self.results_bufnr, 0, 1, false, {})
	end
	end
	local set_ok, msg = pcall(vim.api.nvim_buf_set_lines, self.results_bufnr, row, row + offset, false, { display })
	if set_ok then
	if display_highlights then
	self.highlighter:hi_display(row, prefix, display_highlights)

The hi_display function will loop over the table of highlights and call nvim_buf_add_highlight