Breaking Change: split ext_opts into node_ext_opts and child_ext_opts.

The former is applied to this specific node, the latter to children of
that snippetNode.
Also add merge_{node,child}_ext_opts for control merge-behaviour of eg.
a nodes ext_opts with that of the surrounding snippet (both default to
true).
This is a breaking change because function/dynamicNode no longer have
the variable number of user_args as their last arg. That is now a table,
`opts`, which may contain the `user_args`.

```lua
d(pos, func, argnodes, user_arg1, user_arg2)

-- becomes

d(pos, func, argnodes, {user_args = {user_arg1, user_arg2}})

-- and likewise for functionNode.
```

lua/luasnip/config.lua

@@ -71,7 +71,7 @@ local defaults = {
 		},
 	},
 	ext_base_prio = 200,
-	ext_prio_increase = 7,
+	ext_prio_increase = 9,
 	enable_autosnippets = false,
 	-- default applied in util.parser, requires iNode, cNode
 	-- (Dependency cycle if here).
@@ -90,10 +90,11 @@ c = {
 
 		-- remove unused highlights from default-ext_opts.
 		ext_util.clear_invalid(conf.ext_opts)
-		ext_util.complete(conf.ext_opts)
-		user_config.ext_opts = user_config.ext_opts or {}
-		ext_util.complete(user_config.ext_opts)
-		ext_util.extend(user_config.ext_opts, conf.ext_opts)
+		conf.ext_opts = ext_util.child_complete(conf.ext_opts)
+		user_config.ext_opts = ext_util.child_complete(
+			user_config.ext_opts or {}
+		)
+		ext_util.child_extend(user_config.ext_opts, conf.ext_opts)
 
 		for k, v in pairs(user_config) do
 			conf[k] = v

lua/luasnip/nodes/choiceNode.lua

@@ -69,7 +69,7 @@ local function C(pos, choices, opts)
 		dependents = {},
 		-- default to true.
 		restore_cursor = opts.restore_cursor,
-	})
+	}, opts)
 	c:init_nodes()
 	return c
 end
@@ -112,7 +112,7 @@ function ChoiceNode:put_initial(pos)
 	local mark_opts = vim.tbl_extend("keep", {
 		right_gravity = false,
 		end_right_gravity = false,
-	}, self.parent.ext_opts[self.active_choice.type].passive)
+	}, self.active_choice.ext_opts.passive)
 
 	self.active_choice.mark = mark(old_pos, pos, mark_opts)
 	self.visible = true
@@ -131,7 +131,7 @@ function ChoiceNode:expand_tabs(tabwidth)
 end
 
 function ChoiceNode:input_enter()
-	self.mark:update_opts(self.parent.ext_opts[self.type].active)
+	self.mark:update_opts(self.ext_opts.active)
 	self.parent:enter_node(self.indx)
 
 	self.prev_choice_node = session.active_choice_node
@@ -144,7 +144,7 @@ end
 function ChoiceNode:input_leave()
 	self:event(events.leave)
 
-	self.mark:update_opts(self.parent.ext_opts[self.type].passive)
+	self.mark:update_opts(self.ext_opts.passive)
 	self:update_dependents()
 	session.active_choice_node = self.prev_choice_node
 	self.active = false
@@ -240,7 +240,7 @@ function ChoiceNode:set_choice(choice, current_node)
 	self.active_choice = choice
 
 	self.active_choice.mark = self.mark:copy_pos_gravs(
-		vim.deepcopy(self.parent.ext_opts[self.active_choice.type].passive)
+		vim.deepcopy(self.active_choice.ext_opts.passive)
 	)
 	self.active_choice:put_initial(self.mark:pos_begin_raw())
 
@@ -322,7 +322,7 @@ function ChoiceNode:set_mark_rgrav(rgrav_beg, rgrav_end)
 end
 
 function ChoiceNode:set_ext_opts(name)
-	self.mark:update_opts(self.parent.ext_opts[self.type][name])
+	self.mark:update_opts(self.ext_opts[name])
 	self.active_choice:set_ext_opts(name)
 end
 

lua/luasnip/nodes/dynamicNode.lua

@@ -9,22 +9,24 @@ local conf = require("luasnip.config")
 local FunctionNode = require("luasnip.nodes.functionNode").FunctionNode
 local SnippetNode = require("luasnip.nodes.snippet").SN
 
-local function D(pos, fn, args, ...)
+local function D(pos, fn, args, opts)
+	opts = opts or {}
+
 	return DynamicNode:new({
 		pos = pos,
 		fn = fn,
 		args = node_util.wrap_args(args),
 		type = types.dynamicNode,
 		mark = nil,
-		user_args = { ... },
+		user_args = opts.user_args or {},
 		dependents = {},
 		active = false,
-	})
+	}, opts)
 end
 
 function DynamicNode:input_enter()
 	self.active = true
-	self.mark:update_opts(self.parent.ext_opts[self.type].active)
+	self.mark:update_opts(self.ext_opts.active)
 
 	self:event(events.enter)
 end
@@ -34,7 +36,7 @@ function DynamicNode:input_leave()
 
 	self:update_dependents()
 	self.active = false
-	self.mark:update_opts(self.parent.ext_opts[self.type].passive)
+	self.mark:update_opts(self.ext_opts.passive)
 end
 
 local function snip_init(self, snip)
@@ -159,23 +161,19 @@ function DynamicNode:update()
 	tmp.next = self
 	tmp.prev = self
 
-	tmp.ext_opts = tmp.ext_opts
-		or ext_util.set_abs_prio(
-			vim.deepcopy(self.parent.ext_opts),
-			conf.config.ext_prio_increase
-		)
 	tmp.snippet = self.parent.snippet
-	tmp.mark = self.mark:copy_pos_gravs(
-		vim.deepcopy(self.parent.ext_opts[types.snippetNode].passive)
-	)
+
+	tmp:resolve_child_ext_opts()
+	tmp:resolve_node_ext_opts()
+	tmp:subsnip_init()
+
+	tmp.mark = self.mark:copy_pos_gravs(vim.deepcopy(tmp.ext_opts.passive))
 	tmp.dynamicNode = self
 	tmp.update_dependents = function(node)
 		node:_update_dependents()
 		node.dynamicNode:update_dependents()
 	end
 
-	tmp:subsnip_init()
-
 	tmp:init_positions(self.snip_absolute_position)
 	tmp:init_insert_positions(self.snip_absolute_insert_position)
 
@@ -275,6 +273,8 @@ function DynamicNode:update_static()
 		node.dynamicNode:update_dependents_static()
 	end
 
+	tmp:resolve_child_ext_opts()
+	tmp:resolve_node_ext_opts()
 	tmp:subsnip_init()
 
 	tmp:init_positions(self.snip_absolute_position)
@@ -317,7 +317,7 @@ function DynamicNode:exit()
 end
 
 function DynamicNode:set_ext_opts(name)
-	self.mark:update_opts(self.parent.ext_opts[self.type][name])
+	self.mark:update_opts(self.ext_opts[name])
 	-- might not have been generated (missing nodes).
 	if self.snip then
 		self.snip:set_ext_opts(name)
@@ -336,9 +336,7 @@ function DynamicNode:update_restore()
 		-- prevent entering the uninitialized snip in enter_node in a few lines.
 		local tmp = self.stored_snip
 
-		tmp.mark = self.mark:copy_pos_gravs(
-			vim.deepcopy(self.parent.ext_opts[types.snippetNode].passive)
-		)
+		tmp.mark = self.mark:copy_pos_gravs(vim.deepcopy(tmp.ext_opts.passive))
 		self.parent:enter_node(self.indx)
 		tmp:put_initial(self.mark:pos_begin_raw())
 		tmp:update_restore()

lua/luasnip/nodes/functionNode.lua

@@ -6,14 +6,16 @@ local types = require("luasnip.util.types")
 local events = require("luasnip.util.events")
 local tNode = require("luasnip.nodes.textNode").textNode
 
-local function F(fn, args, ...)
+local function F(fn, args, opts)
+	opts = opts or {}
+
 	return FunctionNode:new({
 		fn = fn,
 		args = node_util.wrap_args(args),
 		type = types.functionNode,
 		mark = nil,
-		user_args = { ... },
-	})
+		user_args = opts.user_args or {},
+	}, opts)
 end
 
 FunctionNode.input_enter = tNode.input_enter

lua/luasnip/nodes/insertNode.lua

@@ -5,7 +5,7 @@ local config = require("luasnip.config")
 local types = require("luasnip.util.types")
 local events = require("luasnip.util.events")
 
-local function I(pos, static_text)
+local function I(pos, static_text, opts)
 	static_text = util.wrap_value(static_text)
 	if pos == 0 then
 		return ExitNode:new({
@@ -16,7 +16,7 @@ local function I(pos, static_text)
 			type = types.exitNode,
 			-- will only be needed for 0-node, -1-node isn't set with this.
 			ext_gravities_active = { false, false },
-		})
+		}, opts)
 	else
 		return InsertNode:new({
 			pos = pos,
@@ -25,7 +25,7 @@ local function I(pos, static_text)
 			dependents = {},
 			type = types.insertNode,
 			inner_active = false,
-		})
+		}, opts)
 	end
 end
 
@@ -90,7 +90,7 @@ function ExitNode:update_dependents_static() end
 function ExitNode:update_all_dependents_static() end
 
 function InsertNode:input_enter(no_move)
-	self.mark:update_opts(self.parent.ext_opts[self.type].active)
+	self.mark:update_opts(self.ext_opts.active)
 	if not no_move then
 		self.parent:enter_node(self.indx)
 
@@ -186,7 +186,7 @@ function InsertNode:input_leave()
 	self:event(events.leave)
 
 	self:update_dependents()
-	self.mark:update_opts(self.parent.ext_opts[self.type].passive)
+	self.mark:update_opts(self.ext_opts.passive)
 end
 
 function InsertNode:exit()

lua/luasnip/nodes/node.lua

@@ -1,21 +1,30 @@
 local session = require("luasnip.session")
 local util = require("luasnip.util.util")
+local types = require("luasnip.util.types")
 local node_util = require("luasnip.nodes.util")
+local ext_util = require("luasnip.util.ext_opts")
 local events = require("luasnip.util.events")
+local conf = require("luasnip.config")
 
 local Node = {}
 
-function Node:new(o)
+function Node:new(o, opts)
 	o = o or {}
-	setmetatable(o, self)
-	self.__index = self
+
 	-- visible is true if the node is visible on-screen, during normal
 	-- expansion, static_visible is needed for eg. get_static_text, where
 	-- argnodes in inactive choices will happily provide their static text,
 	-- which leads to inaccurate docstrings.
 	o.visible = false
 	o.static_visible = false
 	o.old_text = {}
+	-- override existing keys, might be necessary due to double-init from
+	-- snippetProxy, but shouldn't hurt.
+	o = vim.tbl_extend("force", o, node_util.init_node_opts(opts or {}))
+
+	setmetatable(o, self)
+	self.__index = self
+
 	return o
 end
 
@@ -57,7 +66,7 @@ function Node:put_initial(pos)
 end
 
 function Node:input_enter(_)
-	self.mark:update_opts(self.parent.ext_opts[self.type].active)
+	self.mark:update_opts(self.ext_opts.active)
 
 	self:event(events.enter)
 end
@@ -137,7 +146,7 @@ end
 function Node:input_leave()
 	self:event(events.leave)
 
-	self.mark:update_opts(self.parent.ext_opts[self.type].passive)
+	self.mark:update_opts(self.ext_opts.passive)
 end
 
 local function find_dependents(position_self, dict)
@@ -257,7 +266,7 @@ function Node:get_static_args()
 end
 
 function Node:set_ext_opts(name)
-	self.mark:update_opts(self.parent.ext_opts[self.type][name])
+	self.mark:update_opts(self.ext_opts[name])
 end
 
 -- for insert,functionNode.
@@ -307,6 +316,38 @@ function Node:static_init()
 	self.static_visible = true
 end
 
+-- resolve_*node*_ext_opts because snippet(Node)s have child_ext_opts, which
+-- also have to be resolved.
+-- This function generates a nodes ext_opts (those actually used in highlighting).
+function Node:resolve_node_ext_opts(base_prio, parent_ext_opts)
+	-- if self.parent then
+	-- 	local ok, res = pcall(function()
+	-- 		local e = self.parent.effective_child_ext_opts[self.type]
+	-- 	end)
+	-- 	if not ok then
+	-- 		print(self.parent.type == types.snippetNode)
+	-- 		Insp(self.parent.child_ext_opts)
+	-- 		print(self.parent.snippet)
+	-- 		print(self.parent.absolute_position)
+	-- 	end
+	-- end
+
+	if self.merge_node_ext_opts then
+		self.ext_opts = ext_util.extend(
+			vim.deepcopy(self.node_ext_opts),
+			parent_ext_opts or self.parent.effective_child_ext_opts[self.type]
+		)
+	else
+		self.ext_opts = self.node_ext_opts
+	end
+
+	ext_util.set_abs_prio(
+		self.ext_opts,
+		(base_prio or self.parent.ext_opts.base_prio)
+			+ conf.config.ext_prio_increase
+	)
+end
+
 return {
 	Node = Node,
 }