feat(treesitter): add node_for_range function

This is identical to `named_node_for_range` except that it includes
anonymous nodes. This maintains consistency in the API because we
already have `descendant_for_range` and `named_descendant_for_range`.

runtime/doc/news.txt

@@ -166,7 +166,7 @@ TERMINAL
 
 TREESITTER
 
-• TODO
+• |LanguageTree:node_for_range()| gets anonymous and named nodes for a range
 
 TUI
 

runtime/doc/treesitter.txt

@@ -1366,6 +1366,19 @@ LanguageTree:language_for_range({range})
 LanguageTree:named_node_for_range({range}, {opts})
     Gets the smallest named node that contains {range}.
 
+    Parameters: ~
+      • {range}  (`Range4`) `{ start_line, start_col, end_line, end_col }`
+      • {opts}   (`table?`) A table with the following fields:
+                 • {ignore_injections}? (`boolean`, default: `true`) Ignore
+                   injected languages
+
+    Return: ~
+        (`TSNode?`)
+
+                                               *LanguageTree:node_for_range()*
+LanguageTree:node_for_range({range}, {opts})
+    Gets the smallest node that contains {range}.
+
     Parameters: ~
       • {range}  (`Range4`) `{ start_line, start_col, end_line, end_col }`
       • {opts}   (`table?`) A table with the following fields:

runtime/lua/vim/treesitter/languagetree.lua

@@ -1133,6 +1133,18 @@ function LanguageTree:tree_for_range(range, opts)
   return nil
 end
 
+--- Gets the smallest node that contains {range}.
+---
+---@param range Range4 `{ start_line, start_col, end_line, end_col }`
+---@param opts? vim.treesitter.LanguageTree.tree_for_range.Opts
+---@return TSNode?
+function LanguageTree:node_for_range(range, opts)
+  local tree = self:tree_for_range(range, opts)
+  if tree then
+    return tree:root():descendant_for_range(unpack(range))
+  end
+end
+
 --- Gets the smallest named node that contains {range}.
 ---
 ---@param range Range4 `{ start_line, start_col, end_line, end_col }`

test/functional/treesitter/language_spec.lua

@@ -148,4 +148,15 @@ describe('treesitter language API', function()
 
     eq('<node primitive_type>', exec_lua('return tostring(node)'))
   end)
+
+  it('retrieve an anonymous node given a range', function()
+    insert([[vim.fn.input()]])
+
+    exec_lua([[
+      langtree = vim.treesitter.get_parser(0, "lua")
+      node = langtree:node_for_range({0, 3, 0, 3})
+    ]])
+
+    eq('.', exec_lua('return node:type()'))
+  end)
 end)