From 8500dfae515ec4c90ece03b695d6c81ed90893f5 Mon Sep 17 00:00:00 2001
From: Simon Tatham <anakin@pobox.com>
Date: Sun, 13 Apr 2025 08:02:53 +0100
Subject: [PATCH] Bug in conversion from slice

I forgot the analogue of truncating the Vec. But here we can truncate
while it's still in cheap slice form, before making a Vec at all.
---
 src/finitenimber.rs | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/finitenimber.rs b/src/finitenimber.rs
index cb76756..782ff21 100644
--- a/src/finitenimber.rs
+++ b/src/finitenimber.rs
@@ -284,15 +284,17 @@ impl From<Vec<Word>> for FiniteNimber {
 
 impl From<&[Word]> for FiniteNimber {
     fn from(slice: &[Word]) -> FiniteNimber {
-        match slice
+        match dbg!(slice
             .iter()
             .enumerate()
             .rev()
-            .find(|(_index, word)| **word != 0)
+            .find(|(_index, word)| **word != 0))
         {
             None => Self(FiniteNimberEnum::Single(0)),
             Some((0, w)) => Self(FiniteNimberEnum::Single(*w)),
-            Some(_) => Self(FiniteNimberEnum::Vector(slice.into()))
+            Some((pos, _)) => {
+                Self(FiniteNimberEnum::Vector(slice[..=pos].into()))
+            }
         }
     }
 }
-- 
2.30.2