From b89c2d90d32225e0e8feffdf4d156693e005c188 Mon Sep 17 00:00:00 2001
From: Justin Lin <justin.sdk@gmail.com>
Date: Fri, 4 Mar 2022 19:52:16 +0800
Subject: [PATCH] return first when leng is 1

---
 src/util/sum.scad | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/util/sum.scad b/src/util/sum.scad
index 4d66c5ec..06ffa1ad 100644
--- a/src/util/sum.scad
+++ b/src/util/sum.scad
@@ -9,8 +9,7 @@
 **/ 
 
 function sum(lt) = 
-    let(
-        end = len(lt) - 1, 
-        cum_total = [for(i = 0, s = lt[0]; i < end; i = i + 1, s = s + lt[i]) s]
-    )
+    let(end = len(lt) - 1)
+    end == 0 ? lt[0] :
+    let(cum_total = [for(i = 0, s = lt[0]; i < end; i = i + 1, s = s + lt[i]) s])
     cum_total[len(cum_total) - 1] + lt[end];
\ No newline at end of file