From 9d36988946067611719e9a30faec8a4c23f919e3 Mon Sep 17 00:00:00 2001
From: Alessandro Coglio <coglio@kestrel.edu>
Date: Sat, 30 Jul 2022 21:54:29 -0700
Subject: [PATCH] [span] Add doc comment to explain span addition.

---
 compiler/span/src/span.rs | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/compiler/span/src/span.rs b/compiler/span/src/span.rs
index 4cdb3f6fee..c24ebf80f4 100644
--- a/compiler/span/src/span.rs
+++ b/compiler/span/src/span.rs
@@ -71,6 +71,8 @@ impl std::ops::Add for &Span {
 impl std::ops::Add for Span {
     type Output = Self;
 
+    /// Add two spans together.
+    /// The resulting span is the smallest span that includes both.
     fn add(self, other: Self) -> Self {
         let lo = self.lo.min(other.lo);
         let hi = self.hi.max(other.hi);