1 files changed, 29 insertions, 14 deletions
diff --git a/runtime/lua/vim/treesitter/query.lua b/runtime/lua/vim/treesitter/query.lua
index ebed502c92..8383551b5f 100644
--- a/runtime/lua/vim/treesitter/query.lua
+++ b/runtime/lua/vim/treesitter/query.lua
@@ -138,30 +138,43 @@ function M.get_query(lang, query_name)
   end
 end
 
+local query_cache = setmetatable({}, {
+  __index = function(tbl, key)
+    rawset(tbl, key, {})
+    return rawget(tbl, key)
+  end
+})
+
 --- Parse {query} as a string. (If the query is in a file, the caller
----       should read the contents into a string before calling).
+--- should read the contents into a string before calling).
 ---
 --- Returns a `Query` (see |lua-treesitter-query|) object which can be used to
 --- search nodes in the syntax tree for the patterns defined in {query}
 --- using `iter_*` methods below.
 ---
---- Exposes `info` and `captures` with additional information about the {query}.
+--- Exposes `info` and `captures` with additional context about {query}.
 ---   - `captures` contains the list of unique capture names defined in
 ---     {query}.
 ---   -` info.captures` also points to `captures`.
 ---   - `info.patterns` contains information about predicates.
 ---
----@param lang The language
----@param query A string containing the query (s-expr syntax)
+---@param lang string The language
+---@param query string A string containing the query (s-expr syntax)
 ---
 ---@returns The query
 function M.parse_query(lang, query)
   language.require_language(lang)
-  local self = setmetatable({}, Query)
-  self.query = vim._ts_parse_query(lang, query)
-  self.info = self.query:inspect()
-  self.captures = self.info.captures
-  return self
+  local cached = query_cache[lang][query]
+  if cached then
+    return cached
+  else
+    local self = setmetatable({}, Query)
+    self.query = vim._ts_parse_query(lang, query)
+    self.info = self.query:inspect()
+    self.captures = self.info.captures
+    query_cache[lang][query] = self
+    return self
+  end
 end
 
 --- Gets the text corresponding to a given node
@@ -186,11 +199,13 @@ function M.get_node_text(node, source)
       lines = a.nvim_buf_get_lines(source, start_row, end_row + 1, true)
     end
 
-    if #lines == 1 then
-      lines[1]      = string.sub(lines[1], start_col+1, end_col)
-    else
-      lines[1]      = string.sub(lines[1], start_col+1)
-      lines[#lines] = string.sub(lines[#lines], 1, end_col)
+    if #lines > 0 then
+      if #lines == 1 then
+        lines[1]      = string.sub(lines[1], start_col+1, end_col)
+      else
+        lines[1]      = string.sub(lines[1], start_col+1)
+        lines[#lines] = string.sub(lines[#lines], 1, end_col)
+      end
     end
 
     return table.concat(lines, "\n")