From 2dd4f7e9120b66545199b16c86a24efacf92d75b Mon Sep 17 00:00:00 2001
From: Wilfred Hughes <me@wilfred.me.uk>
Date: Tue, 15 Oct 2024 08:37:18 -0700
Subject: [PATCH] Add doc comment

---
 src/line_parser.rs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/line_parser.rs b/src/line_parser.rs
index dfea571f2..226c2a8d9 100644
--- a/src/line_parser.rs
+++ b/src/line_parser.rs
@@ -150,7 +150,12 @@ fn line_len_in_bytes(line: &str) -> usize {
     }
 }
 
-// TODO: Prefer src/opposite_src nomenclature as this function is called from both sides.
+/// Build a vec of MatchedPos, performing a textual diff. Match up
+/// unchanged lines, and match up unchanged words within novel lines.
+///
+/// The resulting vec only has novel items from the LHS. Callers
+/// should do `change_positions(rhs_src, lhs_src)` to obtain
+/// novel MatchedPos values for the RHS.
 pub(crate) fn change_positions(lhs_src: &str, rhs_src: &str) -> Vec<MatchedPos> {
     // TODO: If either side is "", don't split each line by words
     // pointlessly. This is common for file additions/removals.