From 646e4b63c7df401d9c19145b52c10d072cd2256a Mon Sep 17 00:00:00 2001
From: Moritz Althaus <moritzalthaus@gmx.de>
Date: Sun, 17 Mar 2024 15:53:54 +0100
Subject: [PATCH] docs: add motivating module docs string for cache

---
 src/cache.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/cache.rs b/src/cache.rs
index 5d47c1e..de812cb 100644
--- a/src/cache.rs
+++ b/src/cache.rs
@@ -1,3 +1,8 @@
+// Building the Graph from the distance matrix for each start point is computationally expensive.
+// The cache stores the results of previous graph build and tries to understand if any item in the
+// cache which is sufficiently similiar to the current candidate can be used to place an upper bound
+// on the maximum achievable distance with this candidate.
+
 use crate::graph::StartCandidate;
 use flat_projection::FlatPoint;
 use std::collections::HashSet;