diff --git a/src/util/find_index.scad b/src/util/find_index.scad
new file mode 100644
index 00000000..5c102f96
--- /dev/null
+++ b/src/util/find_index.scad
@@ -0,0 +1,5 @@
+function find_index(lt, test) = _find_index(lt, test, len(lt));
+
+function _find_index(lt, test, leng, i = 0) =
+    i == leng ? -1 :
+    test(lt[i]) ? i : _find_index(lt, test, leng, i + 1);
\ No newline at end of file