Re: Customizing the VC backend order

[David Kastrup]

David Kastrup <address@hidden> writes:

> dhruva <address@hidden> writes:
>
>> Hi,
>>
>> On 8/10/07, Stefan Monnier <address@hidden> wrote:
>>> > falling back on CVS (and the rest).  I tried modifying the order in
>>> > "vc-handled-backends" in my dotemacs file.
>>>
>>> That *should* work.
>>
>> I tried with only the following two lines in my dotemacs
>> (load "vc-hg")
>> (setq vc-handled-backends (nconc '(Hg) (delq 'Hg vc-handled-backends)))
>
> Yikes!!!!!  Please _never_ use nconc unless you have a license to do
> so.  Do you know what the last line will do when executed more than
> once?

Well, at least when you actually _read_ the line once.  So try the
following example.  Can you figure out what happens?

(setq xxx (copy-sequence vc-handled-backends))
(dotimes (i 3)
  (setq xxx (nconc '(Hg) (delq 'Hg xxx))))
xxx

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum