From cc9bcc6e9d376706ebe8110cc78825b151e8d29d Mon Sep 17 00:00:00 2001
From: Justin Lin <caterpillar@openhome.cc>
Date: Thu, 19 Mar 2020 20:32:09 +0800
Subject: [PATCH] refactor to zip

---
 src/experimental/_impl/_zip_impl.scad | 11 +++++++++++
 src/experimental/zip.scad             |  5 +++++
 src/experimental/zip2.scad            |  2 --
 src/experimental/zip3.scad            |  2 --
 4 files changed, 16 insertions(+), 4 deletions(-)
 create mode 100644 src/experimental/_impl/_zip_impl.scad
 create mode 100644 src/experimental/zip.scad
 delete mode 100644 src/experimental/zip2.scad
 delete mode 100644 src/experimental/zip3.scad

diff --git a/src/experimental/_impl/_zip_impl.scad b/src/experimental/_impl/_zip_impl.scad
new file mode 100644
index 00000000..ddc115c3
--- /dev/null
+++ b/src/experimental/_impl/_zip_impl.scad
@@ -0,0 +1,11 @@
+function _zip2(lt1, lt2) =
+    [for(i = [0:len(lt1) - 1]) [lt1[i], lt2[i]]];
+
+function _zip3(lt1, lt2, lt3) =
+    [for(i = [0:len(lt1) - 1]) [lt1[i], lt2[i], lt3[i]]];
+
+function _zipAll_sub(lists, list_to, elem_to, i = 0) = 
+    i > elem_to ? [] :
+    concat([[for(j = [0:list_to]) lists[j][i]]], _zipAll_sub(lists, list_to, elem_to, i + 1));
+
+function _zipAll(lists) = _zipAll_sub(lists, len(lists) - 1, len(lists[0]) - 1);
\ No newline at end of file
diff --git a/src/experimental/zip.scad b/src/experimental/zip.scad
new file mode 100644
index 00000000..5096f063
--- /dev/null
+++ b/src/experimental/zip.scad
@@ -0,0 +1,5 @@
+use <experimental/_impl/_zip_impl.scad>;
+
+function zip(lt, lt2, lt3) = 
+    is_undef(lt2) ? _zipAll(lt) :
+    is_undef(lt3) ? _zip2(lt, lt2) : _zip3(lt, lt2, lt3);
\ No newline at end of file
diff --git a/src/experimental/zip2.scad b/src/experimental/zip2.scad
deleted file mode 100644
index 32820077..00000000
--- a/src/experimental/zip2.scad
+++ /dev/null
@@ -1,2 +0,0 @@
-function zip2(lt1, lt2) =
-    [for(i = [0:len(lt1) - 1]) [lt1[i], lt2[i]]];
\ No newline at end of file
diff --git a/src/experimental/zip3.scad b/src/experimental/zip3.scad
deleted file mode 100644
index 6ce8a41e..00000000
--- a/src/experimental/zip3.scad
+++ /dev/null
@@ -1,2 +0,0 @@
-function zip3(lt1, lt2, lt3) =
-    [for(i = [0:len(lt1) - 1]) [lt1[i], lt2[i]. lt3[i]]];
\ No newline at end of file