From ingvar at hexapodia.net  Thu Feb 19 08:43:35 2009
From: ingvar at hexapodia.net (Ingvar)
Date: Thu, 19 Feb 2009 08:43:35 +0000
Subject: [noctool-devel] New CLUSTER macro! And a WITH-FORMAT to go with it!
Message-ID: <E1La4VN-0005Ms-1e@head.hexapodia.net>

The cluster config macro has had some problems, in that it can do one thing 
(and one thing only), normally the name, numbered in the normal style.

So, in a fit of "let's make this better and trivially nestable", I cooked up a 
new cluster macro. It's subtly different from the old one, but configs that 
use the non-complicated version of the old one should work identically under 
the new one.

(cluster (<fmt-string> <low> <high> &key c-fmt name counter)
  <stanza to be repeated>)

:name <name> specifys a symbol to be replaced, instead of the default NAME
:c-fmt decides if a conversion from C-style format to lisp style format 
  should happen (still defaults to true, but by happy co-incidence, the 
  ~-style lisp arguments are NOT mangled by the C-style conversion, strictly 
  speaking a bug, but maybe not worth fixing at the moment)
:counter is NEW, this specifies a counter to be sequentially set from low to 
  high in the expansion. This defaults to a gensym, so cannot be used without 
  specifying it.

(with-format ((sym1 fmt1 vars1... ) (sym2 fmt2 vars2 ...))
  <config stanza>)

Like LET, only, eh, thing...

I also cooked up an example (in test-files/nested-cluster.cfg):
(cluster ("" 1 2 :counter a)
  (cluster ("" 1 2 :counter b)
    (with-format ((name "node~d-cpu~d" a b)
                  (ip-addr "172.23.~d.~d" a b))
       (machine name linux-host
	 (user "testuser")
         (ip ip-addr)))))

Somewhat annoyingly, when I test-ran this I noticed that our post-creation 
clean-up for EQUIPMENT objects is a bit... aggressive. When created from a 
config stanza, the ONLY thing specified is the name, all else is (eventually) 
done with (setf *config-object* 'slot-to-set <value>) or pushing things onto 
the monitor list, as it were. 

While the clean-up done in the initialize-after method is good, I am wondering
if it may be worth creating a new "post-config-cleanup" GF and move the relevant 
clean-up bits to there, as I actually had to re-define the :after method t do 
nothing to be able to run my tests (it's vastly easier to use example names to 
see if things work or not, when one doesn't actually have a cluster at hand).

//Ingvar