BREAKING: Make last arg to snippet a table and remove varargs.

Last arg table: More flexible, nicer for options that don't depend on
one another (nicer than a bunch of `nil`s before the next important
bit).

No varargs: With a table last, it doesn't really make much sense to keep
the (in some cases unrelated) user-arguments (plus they will eventually
be removed from function/dynamicNode as well, they only exist because I
didn't know how easy it is to do partial functions in lua).

DOC.md

@@ -67,12 +67,10 @@ The second argument to `s` is a table containing all nodes that belong to the
 snippet. If the table only has a single node, it can be passed directly
 without wrapping it in a table.
 
-The third argument is the condition-function. The snippet will be expanded only
-if it returns true (default is a function that just returns true) (the function
-is called before the text is modified in any way).
-
-The fourth and following args are passed to the condition-function(allows
-reusing condition-functions).
+The third argument is a table with the following valid keys:
+- `cond`: the condition-function. The snippet will be expanded only
+          if it returns true (default is a function that just returns true)
+          (the function is called before the text is modified in any way).
 
 Snippets contain some interesting tables, eg. `snippet.env` contains variables
 used in the LSP-protocol like `TM_CURRENT_LINE` or `TM_FILENAME` or

lua/luasnip/nodes/snippet.lua

@@ -87,12 +87,8 @@ local function wrap_nodes(nodes)
 	end
 end
 
-local function S(context, nodes, condition, ...)
-	if not condition then
-		condition = function()
-			return true
-		end
-	end
+local function S(context, nodes, opts)
+	opts = opts or {}
 
 	if type(context) == "string" then
 		context = { trig = context }
@@ -123,8 +119,7 @@ local function S(context, nodes, condition, ...)
 		nodes = nodes,
 		insert_nodes = {},
 		current_insert = 0,
-		condition = condition,
-		user_args = { ... },
+		condition = opts.condition or function() return true end,
 		mark = nil,
 		dependents = {},
 		active = false,
@@ -362,7 +357,7 @@ function Snippet:matches(line_to_cursor)
 		return nil
 	end
 
-	if not self.condition(unpack(self.user_args)) then
+	if not self.condition() then
 		return nil
 	end