Day 18 part 2. This needed some optimization

1 files changed, 5 insertions, 1 deletions

diff --git a/readme.org b/readme.org
index 936550a..e189346 100644
--- a/readme.org
+++ b/readme.org
@@ -18,4 +18,8 @@ program should only be pure expressions.
 - Using "new type" structs can be a pain. derive_more crate made most
   of that pain go away.
 - With immutable types, 'reset the machine to try again' type
-  constraints were handled for free.
+  constraints were handled for free. This made many later puzzles easier.
+- The 'no statement' constraint meant that some functions ended up
+  nested in a way that makes it harder to name and read.
+- The persistent data structures don't integrate with Rayon iterators.
+- Easier to test subsets, but harder to inspect and audit runtime behaviour.