From pengyu.ut at gmail.com  Fri Dec  4 03:38:52 2009
From: pengyu.ut at gmail.com (Peng Yu)
Date: Thu, 3 Dec 2009 20:38:52 -0600
Subject: [Rd] Tabs in R source code
In-Reply-To: <4B12ACDF.2030506@stats.uwo.ca>
References: <366c6f340911290758t71dd256dtd7975a49ae9155a7@mail.gmail.com>
	<4B12A3FD.9010006@stats.uwo.ca>
	<366c6f340911290850o3d4e16dfg3e2318339f0b0f92@mail.gmail.com>
	<4B12ACDF.2030506@stats.uwo.ca>
Message-ID: <366c6f340912031838i36fbcc56l533a927e194caa12@mail.gmail.com>

On Sun, Nov 29, 2009 at 11:18 AM, Duncan Murdoch <murdoch at stats.uwo.ca> wrote:
> On 29/11/2009 11:50 AM, Peng Yu wrote:
>>
>> On Sun, Nov 29, 2009 at 10:40 AM, Duncan Murdoch <murdoch at stats.uwo.ca>
>> wrote:
>>>
>>> On 29/11/2009 10:58 AM, Peng Yu wrote:
>>>>
>>>> Some lines are indented by tabs and some lines are indented by spaces,
>>>> in R source code. This might due to the fact that the source code is
>>>> not from a single person. But I think that it is better to enforce a
>>>> single convention.
>>>>
>>>> My editor defaults a tab to 8 spaces. So some source doesn't seem to
>>>> be indented correctly in my editor. Since tab may be displayed
>>>> differently in different editor, I recommend to replace all the tabs
>>>> by the appropriate number of spaces to ensure the same indentation
>>>> display.
>>>
>>> The R source code assumes that tabs occur every 8 columns, so if your
>>> editor
>>> is working properly, it should display files as intended.
>>>
>>>> Could somebody update the source code in the future version by
>>>> replacing tabs by spaces and enforce such a coding convention in the
>>>> future?
>>>
>>> No, that would not be feasible, for the reason you give in the second
>>> sentence of your post.
>>
>> I don't understand why it is not feasible. The spaces are displayed
>> the same in all editors. If there are no tabs, the code should display
>> the same in all editors. I know some languages that are recommended to
>> have spaces rather than tabs for this reason.
>
> It is not feasible because it would require everyone who edits the source
> code to change the configuration of their editors. ?In my case, that would
> require changing about 3 different types of editors (I work on several
> different platforms). ?I would probably miss one, and re-introduce tabs the
> next time I edited a file on that editor.

http://google-styleguide.googlecode.com/svn/trunk/google-r-style.html

Here is the R style, which does not recommend using tabs. Although it
might take some time to forbidden the use of tabs, it will eventually
be a good practice that benefits everyone in the future.

> I've already seen problems in the NEWS and CHANGES files, which have
> recently changed to UTF-8 encoding. ?It's very irritating that my editor
> switches back to the Windows default if it doesn't see a byte-order mark,
> and that some editors that I use automatically delete the BOM. Requiring a
> particular "encoding" for tabs (i.e. converting them to spaces) would lead
> to the same problems, but on a much bigger scale.
>
> Duncan Murdoch
>



[Rd] Tabs in R source code
Peng Yu