treesitter: default start and end row when omitted

Add support for default start and end row when omitted in the
query:iter_captures and query:iter_matches functions.

When the start and end row values are omitted, the values of the given
node is used. The end row value is incremented by 1 to include the node end
row in the match.

Updated tests and docs accordingly.

2 files changed, 14 insertions, 1 deletions

diff --git a/runtime/doc/treesitter.txt b/runtime/doc/treesitter.txt
index 911e7b8b47..1696d3b9ba 100644
--- a/runtime/doc/treesitter.txt
+++ b/runtime/doc/treesitter.txt
@@ -195,7 +195,8 @@ query:iter_captures({node}, {bufnr}, {start_row}, {end_row})
 	text of the buffer. {start_row} and {end_row} can be used to limit
 	matches inside a row range (this is typically used with root node
 	as the node, i e to get syntax highlight matches in the current
-	viewport)
+	viewport). When omitted the start and end row values are used from
+        the given node.
 
 	The iterator returns three values, a numeric id identifying the capture,
 	the captured node, and metadata from any directives processing the match.
diff --git a/runtime/lua/vim/treesitter/query.lua b/runtime/lua/vim/treesitter/query.lua
index 5a27d740a2..9d1f265e54 100644
--- a/runtime/lua/vim/treesitter/query.lua
+++ b/runtime/lua/vim/treesitter/query.lua
@@ -353,6 +353,12 @@ function Query:iter_captures(node, source, start, stop)
   if type(source) == "number" and source == 0 then
     source = vim.api.nvim_get_current_buf()
   end
+
+  if start == nil and stop == nil then
+    start, _, stop, _ = node:range()
+    stop = stop + 1 -- Make stop inclusive
+  end
+
   local raw_iter = node:_rawquery(self.query, true, start, stop)
   local function iter()
     local capture, captured_node, match = raw_iter()
@@ -385,6 +391,12 @@ function Query:iter_matches(node, source, start, stop)
   if type(source) == "number" and source == 0 then
     source = vim.api.nvim_get_current_buf()
   end
+
+  if start == nil and stop == nil then
+    start, _, stop, _ = node:range()
+    stop = stop + 1 -- Make stop inclusive
+  end
+
   local raw_iter = node:_rawquery(self.query, false, start, stop)
   local function iter()
     local pattern, match = raw_iter()