() Eric Abrahamsen <eric@ericabrahamsen.net>
() Sun, 06 Oct 2013 17:35:30 +0800

   What's the best way of handling this?

Check out ‘copy-tree’, e.g.:

 (let ((list-template (copy-tree list-template)))
   ...)

See also:

 http://www.emacswiki.org/emacs/ElispCookbook

which compares ‘copy-sequence’ and ‘copy-tree’ in section "Copying".

WRT, lexical vs dynamic binding, the code is written to assume dynamic
binding, so you might want to explicitly set ‘lexical-binding’ to nil
somewhere.

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