1 files changed, 123 insertions, 0 deletions
diff --git a/runtime/lua/vim/treesitter.lua b/runtime/lua/vim/treesitter.lua
index 70f2c425ed..6431162799 100644
--- a/runtime/lua/vim/treesitter.lua
+++ b/runtime/lua/vim/treesitter.lua
@@ -118,4 +118,127 @@ function M.get_string_parser(str, lang, opts)
   return LanguageTree.new(str, lang, opts)
 end
 
+--- Determines whether a node is the ancestor of another
+---
+---@param dest table the possible ancestor
+---@param source table the possible descendant node
+---
+---@returns (boolean) True if dest is an ancestor of source
+function M.is_ancestor(dest, source)
+  if not (dest and source) then
+    return false
+  end
+
+  local current = source
+  while current ~= nil do
+    if current == dest then
+      return true
+    end
+
+    current = current:parent()
+  end
+
+  return false
+end
+
+--- Get the node's range or unpack a range table
+---
+---@param node_or_range table
+---
+---@returns start_row, start_col, end_row, end_col
+function M.get_node_range(node_or_range)
+  if type(node_or_range) == 'table' then
+    return unpack(node_or_range)
+  else
+    return node_or_range:range()
+  end
+end
+
+---Determines whether (line, col) position is in node range
+---
+---@param node Node defining the range
+---@param line A line (0-based)
+---@param col A column (0-based)
+function M.is_in_node_range(node, line, col)
+  local start_line, start_col, end_line, end_col = M.get_node_range(node)
+  if line >= start_line and line <= end_line then
+    if line == start_line and line == end_line then
+      return col >= start_col and col < end_col
+    elseif line == start_line then
+      return col >= start_col
+    elseif line == end_line then
+      return col < end_col
+    else
+      return true
+    end
+  else
+    return false
+  end
+end
+
+---Determines if a node contains a range
+---@param node table The node
+---@param range table The range
+---
+---@returns (boolean) True if the node contains the range
+function M.node_contains(node, range)
+  local start_row, start_col, end_row, end_col = node:range()
+  local start_fits = start_row < range[1] or (start_row == range[1] and start_col <= range[2])
+  local end_fits = end_row > range[3] or (end_row == range[3] and end_col >= range[4])
+
+  return start_fits and end_fits
+end
+
+---Gets a list of captures for a given cursor position
+---@param bufnr number The buffer number
+---@param row number The position row
+---@param col number The position column
+---
+---@returns (table) A table of captures
+function M.get_captures_at_position(bufnr, row, col)
+  if bufnr == 0 then
+    bufnr = a.nvim_get_current_buf()
+  end
+  local buf_highlighter = M.highlighter.active[bufnr]
+
+  if not buf_highlighter then
+    return {}
+  end
+
+  local matches = {}
+
+  buf_highlighter.tree:for_each_tree(function(tstree, tree)
+    if not tstree then
+      return
+    end
+
+    local root = tstree:root()
+    local root_start_row, _, root_end_row, _ = root:range()
+
+    -- Only worry about trees within the line range
+    if root_start_row > row or root_end_row < row then
+      return
+    end
+
+    local q = buf_highlighter:get_query(tree:lang())
+
+    -- Some injected languages may not have highlight queries.
+    if not q:query() then
+      return
+    end
+
+    local iter = q:query():iter_captures(root, buf_highlighter.bufnr, row, row + 1)
+
+    for capture, node, metadata in iter do
+      if M.is_in_node_range(node, row, col) then
+        local c = q._query.captures[capture] -- name of the capture in the query
+        if c ~= nil then
+          table.insert(matches, { capture = c, priority = metadata.priority })
+        end
+      end
+    end
+  end, true)
+  return matches
+end
+
 return M