From 84bd2088e53adf8ab4c2956067baa0d54d06d552 Mon Sep 17 00:00:00 2001
From: Garth Minette <gminette@gmail.com>
Date: Sat, 20 Mar 2021 01:37:46 -0700
Subject: [PATCH] Optimized cleanup_path() and list_rotate()

---
 arrays.scad | 9 ++++++++-
 paths.scad  | 6 ++++--
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/arrays.scad b/arrays.scad
index 7c420b5..3fd8bbc 100644
--- a/arrays.scad
+++ b/arrays.scad
@@ -432,7 +432,14 @@ function reverse(x) =
 function list_rotate(list,n=1) =
     assert(is_list(list)||is_string(list), "Invalid list or string.")
     assert(is_finite(n), "Invalid number")
-    let (elems = select(list,n,n+len(list)-1))
+    let (
+        ll = len(list),
+        n = ((n % ll) + ll) % ll,
+        elems = [
+            for (i=[n:1:ll-1]) list[i],
+            for (i=[0:1:n-1]) list[i]
+        ]
+    )
     is_string(list)? str_join(elems) : elems;
 
 
diff --git a/paths.scad b/paths.scad
index 06a5f7e..5d391c3 100644
--- a/paths.scad
+++ b/paths.scad
@@ -62,7 +62,8 @@ function is_closed_path(path, eps=EPSILON) = approx(path[0], path[len(path)-1],
 //   close_path(path);
 // Description:
 //   If a path's last point does not coincide with its first point, closes the path so it does.
-function close_path(path, eps=EPSILON) = is_closed_path(path,eps=eps)? path : concat(path,[path[0]]);
+function close_path(path, eps=EPSILON) =
+    is_closed_path(path,eps=eps)? path : concat(path,[path[0]]);
 
 
 // Function: cleanup_path()
@@ -70,7 +71,8 @@ function close_path(path, eps=EPSILON) = is_closed_path(path,eps=eps)? path : co
 //   cleanup_path(path);
 // Description:
 //   If a path's last point coincides with its first point, deletes the last point in the path.
-function cleanup_path(path, eps=EPSILON) = is_closed_path(path,eps=eps)? select(path,0,-2) : path;
+function cleanup_path(path, eps=EPSILON) =
+    is_closed_path(path,eps=eps)? [for (i=[0:1:len(path)-2]) path[i]] : path;
 
 
 // Function: path_subselect()