From c916f471caada4eb9a4b7f9f53925a71525c694a Mon Sep 17 00:00:00 2001
From: Yuan Fu <casouri@gmail.com>
Date: Wed, 13 Sep 2023 17:56:07 -0700
Subject: [PATCH] Add tree-sitter performance note

---
 admin/notes/tree-sitter/performance | 12 ++++++++++++
 1 file changed, 12 insertions(+)
 create mode 100644 admin/notes/tree-sitter/performance

diff --git a/admin/notes/tree-sitter/performance b/admin/notes/tree-sitter/performance
new file mode 100644
index 00000000000..0e8351403af
--- /dev/null
+++ b/admin/notes/tree-sitter/performance
@@ -0,0 +1,12 @@
+TREE-SITTER PERFORMANCE NOTES -*- org -*-
+
+* Facts
+
+Incremental parsing of a few characters worth of edit usually takes
+less than 0.1ms. If it takes longer than that, something is wrong.  There’s one time where I found tree-sitter-c takes ~30ms to incremental parse. Updating to the latest version of tree-sitter-c solves it, so I didn’t investigate further.
+
+The ranges set for a parser doesn’t grow when you insert text into a
+range, so you have to update the ranges every time before
+parsing. Fortunately, changing ranges doesn’t invalidate incremental
+parsing, so there isn’t any performance lost in update ranges
+frequently.
-- 
2.39.5