* fix#11352 strutil.insertSep handle negtive number
* test for #11352
* optimize
* not parts string var
* Update lib/pure/strutils.nim
Thanks!
Co-authored-by: alaviss <leorize+oss@disroot.org>
* need to be countdown
Co-authored-by: alaviss <leorize+oss@disroot.org>