Re: Refining ediff's idea of a difference?

[Eli Zaretskii]

> From: Doug Lewan <dougl@shubertticketing.com>
> Date: Fri, 30 Jan 2015 23:11:41 +0000
> 
> Using ediff I find that very often one difference one difference seems 
> inappropriately large and might obscure a small difference.
> 
> In the example at hand I have the two following diffs:
> 
>     <<<< A
>      -clrobj server_info_blk -fid server_info_begin_time  -val 2015-01-29 
> 15:28:47
>     >>>> B
>      -clrobj server_info_blk -fid server_info_begin_time  -val 2015-01-29 
> 15:27:28
>     -fid server_info_reply_que  -val 
>     -fid server_info_tran_msg_type  -val 
>     -fid server_info_tran_id  -val 
>     -fid server_info_seq_msg_type  -val 
>     -fid server_info_seq_id  -val 
>     ...
> 
> The lines following diff A are these
>     <<<< A
>     -fid server_info_reply_que  -val 
>     -fid server_info_tran_msg_type  -val 
>     -fid server_info_tran_id  -val 
>     -fid server_info_seq_msg_type  -val 
>     -fid server_info_seq_id  -val 
> which look, to my eye, identical to those flagged as different in diff B.
> 
> I'd rather those lines are recognized as identical, so the diff is minimal. 
> Is there a conventional way to do that?

Ediff just obeys here what the Diff utility outputs.  So try playing
with Diff switches, like -d, -b, -B, -w, --horizon-lines.

> I haven't found anything obvious in ediff customization. Browsing the code 
> didn't reveal much more than the fact that ediff seems to use diff with no 
> options. It clearly does more with that information.

The relevant defcustom is ediff-diff-options.