Tomi,

On Tue, 20 Dec 2011 10:02:11 +0200, Tomi Ollila <tomi.ollila@iki.fi> wrote:
> 
> Are the last few lines above working... if without '(' and no
> loop (nor for) function in my emacs (where notmuch loaded).

This is the `loop' macro from cl.el.  It mimics a Common Lisp idiom
which, strangely enough, looks nothing like Lisp but is sort of a DSL
for specifying imperative loops.  You can find the documentation by
doing C-h i (to open the Info manual in Emacs) then following the “CL”
link.

(One of the coolest features is that it is all implemented via macros,
so the compiler automatically unrolls it into a native Lisp loop.  Thus
the performance hit, if any, is negligible.)

> 
> ... memq is also nice; in case used the list should be done beforehand with
> (let* ...

Given the fact about loop, let* isn’t really applicable.

-- 
Aaron Ecay