From: Andreas Ericsson <ae@op5.se>
Date: Tue, 06 Nov 2007 09:47:20 GMT
Subject: Re: [PATCH 4/4] Implement git commit and status as a builtin commands.
Message-ID: <47303828.3060106@op5.se>
In-Reply-To: <20071106092648.GG4435@artemis.corp>

Pierre Habouzit wrote:
> On Tue, Nov 06, 2007 at 09:18:02AM +0000, Johannes Sixt wrote:
>> Pierre Habouzit schrieb:
>>> Btw, I'm starting to work slowly on the diff_opt_parse conversion to the
>>> macro we discussed, and the need for new option parsing callbacks
>>> arised, and I've created a:
>>>  parse_opt_mask_{or,and,xor} commands that you declare this way:
>>>    OPT_MASK_OR('a', "all",         &mode, "...", MASK_ALL),
>>>    OPT_MASK_OR('i', "interactive", &mode, "...", MASK_INTERACTIVE),
>>>    ...
>>> And if you chose MASK_ALL/INTERACTIVE/.. to be single bits,
>>>    if (!!all + !!interactive ... > 1)
>>> becomes[0]:
>>>    if (mode & (mode - 1)) {
>>>    }
>> This goes too far, IMHO. That's unnecessary cleverness/microoptimization 
>> at the expense of readability.
> 
> The reason why I did that is not to be able to do mode & (mode - 1).

With a macro along the lines of

  #define IS_MULTI_FLAGGED(x) (x & (x - 1))

at least this particular construct becomes a lot more readable.

-- 
Andreas Ericsson                   andreas.ericsson@op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231