feat(treesitter): async parsing

**Problem:** Parsing can be slow for large files, and it is a blocking
operation which can be disruptive and annoying.

**Solution:** Provide a function for asynchronous parsing, which accepts
a callback to be run after parsing completes.

Co-authored-by: Lewis Russell <lewis6991@gmail.com>
Co-authored-by: Luuk van Baal <luukvbaal@gmail.com>
Co-authored-by: VanaIgr <vanaigranov@gmail.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/src/nvim/lua/treesitter.c b/src/nvim/lua/treesitter.c
index 28ad2cf4d3..9bd2baad27 100644
--- a/src/nvim/lua/treesitter.c
+++ b/src/nvim/lua/treesitter.c
@@ -489,7 +489,11 @@ static int parser_parse(lua_State *L)
   // Sometimes parsing fails (timeout, or wrong parser ABI)
   // In those case, just return an error.
   if (!new_tree) {
-    return luaL_error(L, "An error occurred when parsing.");
+    if (ts_parser_timeout_micros(p) == 0) {
+      // No timeout set, must have had an error
+      return luaL_error(L, "An error occurred when parsing.");
+    }
+    return 0;
   }
 
   // The new tree will be pushed to the stack, without copy, ownership is now to the lua GC.