From: Luke Lu <git@vicaya.com>
Date: Wed, 17 Oct 2007 10:03:46 GMT
Subject: Re: On Tabs and Spaces
Message-ID: <A73C6BE2-F990-4634-B996-02CB9B129155@vicaya.com>
In-Reply-To: <E29971BA-7306-4570-8383-26D0C9C0B814@mit.edu>


On Oct 17, 2007, at 2:09 AM, Michael Witten wrote:
>
> On 17 Oct 2007, at 3:17:08 AM, Luke Lu wrote:
>
>> But I still haven't seen any compelling arguments against the "all  
>> space" case
>
> Overhead!
>
> If you use 8 spaces instead of one tab,
> that's using up 7x more space!
>
> Consider:
>
>     # calculates the extra space required to
>     # use the given number of spaces/tab.
>     size()
>     {
>         count=`grep -RIo "\`printf \"\t\"\`" . | wc -l`;
>         perl -e "print $count*$(($1-1))/1024/1024 . \" MB\n\"";
>     }
>
>     Then in in a git working tree:
>
>         size 8; # 1.28701210021973 MB
>         size 4; # 0.551576614379883 MB

First, the overhead is not a simple x4 or x8 conversion in size, but  
it's the upper bound. Given that, let's look at the percentage of the  
overhead: my git working tree is 56MB after gc, so the overhead is  
2.3% max for size 8 and 0.98% for size 4. That's not significant at all.

>
>     In a linux kernel working tree:
>
>         size 8; # 61.4902725219727 MB
>         size 4; # 26.3529739379883 MB
>
> Conclusion:
>
>     Yikes!

Now, compile the kernel, do a du in the tree and report back  
percentages of the overhead.

Disk is cheap (1GB costs less than half a dollar), people's  
productivity/time is not. The overhead argument is compelling, not!

__Luke