feat(nvim): focus-aware cursor line via per-window highlight namespaces

Split 50-highlight.lua into 40-colors.lua (colorscheme, custom
highlights, per-window namespaces, focus tracking) and 50-extmarks.lua
(TODO scanner reading the namespace contract from vim.g.dotfiles). The
40- prefix guarantees colors load before extmarks.

Focused vs unfocused windows now differ by cursor-line color and a
CursorLineNr badge in the focus hue (green on dark, magenta on light);
the number column stays visible on closed folds where CursorLine cannot.

1 files changed, 0 insertions, 100 deletions

diff --git a/.config/nvim/plugin/50-highlight.lua b/.config/nvim/plugin/50-highlight.lua
deleted file mode 100644
index a509a86..0000000
--- a/.config/nvim/plugin/50-highlight.lua
+++ /dev/null
@@ -1,100 +0,0 @@
---
--- Custom highlighting plugin
---
-
--- Returns an iterator over the ascendants of `node`, starting at the root node
-local function node_ascendants(node)
-	local root = node:tree():root()
-	local current = root
-	return function()
-		if current:equal(node) then
-			return nil
-		end
-		current = assert(current:child_with_descendant(node))
-		return current
-	end
-end
-
--- Returns true if `node` or any of its parent has the type `type`
-local function node_within_type(node, type)
-	local next_ascendant = node_ascendants(node)
-	local next = next_ascendant()
-	while next do
-		if next:type() == type then
-			return true
-		end
-		next = next_ascendant()
-	end
-	return false
-end
-
--- Returns an iterator over the positions (`{ col1, col2, row }`) of matches of pattern in lines
-local function pmatches(lines, pattern)
-	local col1, col2, row = nil, nil, 1
-	return function()
-		while row < #lines do
-			col1, col2 = string.find(lines[row], pattern, (col2 or 0) + 1)
-			if col1 then
-				return { col1 = col1, col2 = col2, row = row }
-			else
-				col1, col2, row = 0, 0, row + 1
-			end
-		end
-		return nil
-	end
-end
-
--- Set extmarks are the positions (`{ col1, col2, row }`) given by `next_pos()`
--- `opts`: {
---     ns: highlight namespace
---     predicate: is passed row and col, if true then set the mark
---     hl_group: highlight group
---  }
-local function set_extmarks(next_pos, opts)
-	for pos in next_pos do
-		local marks = vim.api.nvim_buf_get_extmarks(
-			0,
-			opts.ns,
-			{ pos.row - 1, pos.col1 - 1 },
-			{ pos.row - 1, pos.col2 - 1 },
-			{}
-		)
-		if #marks == 0 and opts.predicate(pos.row - 1, pos.col1 - 1) then
-			vim.api.nvim_buf_set_extmark(
-				0,
-				opts.ns,
-				pos.row - 1,
-				pos.col1 - 1,
-				{ end_col = pos.col2, hl_group = opts.hl_group }
-			)
-		end
-	end
-end
-
--- TODO a better way to do this:
--- For code, only check in "comment" node ranges
--- For non-code, do it per type. For Markdown, only check "paragraph" nodes
-local function hl_todo_predicate(row, col)
-	if vim.o.filetype == "markdown" or vim.treesitter.get_parser() == nil then
-		return true
-	end
-	local node = assert(vim.treesitter.get_node({ pos = { row, col } }))
-	return node_within_type(node, "comment")
-end
-
-local patterns = { todo = "TODO" }
-local hl_ns = vim.api.nvim_create_namespace("extmarks")
-
-vim.api.nvim_set_hl(hl_ns, "dotfiles.Todo", { bg = "Yellow", fg = "Black", bold = true })
-local extmarks_todo_opts = { ns = hl_ns, hl_group = "dotfiles.Todo", predicate = hl_todo_predicate }
-
--- Initialize extmarks
-vim.api.nvim_create_autocmd("FileType", {
-	desc = "Initialize extmarks",
-	group = vim.g.dotfiles.augroup,
-	callback = function()
-		vim.api.nvim_win_set_hl_ns(vim.api.nvim_get_current_win(), hl_ns)
-		local lines = vim.api.nvim_buf_get_lines(0, 0, -1, false)
-		set_extmarks(pmatches(lines, patterns.todo), extmarks_todo_opts)
-	end,
-})