Re: How to change the length of "\t"?

"Alf P. Steinbach" <>
Tue, 15 Jul 2008 23:17:21 +0200
* James Kanze:

On Jul 15, 7:01 pm, "Alf P. Steinbach" <> wrote:

* James Kanze:

Using anything other than 8 for tabstops is a dumb thing,
since that's the universal defacto standard today (and you
certainly don't look at text only in an editor).

I'm sorry, but that's not correct. The de facto Windows
standard is 4 character positions per tab stop. Tools from
early eighties (e.g. Notepad) excepted.

Windows doesn't make the standard

It is of course the common practice for Windows that sets that Windows de-facto
standard; maintaining anything else is just silly.

it was established long before windows appeared.

Well, that olde "standard" was tab size 8 or 10 (!), for printers.

And a quick check on my Windows machine showed it using 8 as
well (under Windows XP).

Dunno what you checked but obviously the Wrong Thing. ;-)

 So I'm not sure what you're talking
about when you speak of 4; until your statement above, I had
assumed that it was a personal configuration of the editor.

No, it isn't. Nearly all Microsoft code uses tab size 4. So do nearly all
Windows programmer's editors, and reportedly that's also the case on the Mac.

If they did try to make it 4... Trying to change such an
established standard is almost as dumb as another systems
attempt to change the de facto standard for line endings (which
is, of course, CR,LF).

He he. Everybody knows it's just CR. Nobody'd be fool enough to use anything
but a Mac.

Regarding what's dumb, the *nix de facto standard of 8
character positions per tab stop is clearly dumb, since it's
impractical for anything,

Historically, I don't know where the 8 comes from; it was the de
facto standard before I got into computer programming, and that
goes back some. Before Windows or Unix.

Wikipedia, which as we all know is the final arbiter of such questions, the
highest authority[1], says "it is unclear why the 8-character horizontal size
was chosen [for printers], as 5 characters, half inch in a typical printer at
that time [no reference or timeframe given], was much more popular at that time
as a paragraph indentation. It may have been chosen to match early Fortran
conventions for where the statement text started after the line number and
continuation character. Or it may have been chosen as the smallest size that
would fit numbers typically printed in a table."

and the lack of a standard for indicating the tab stop and
indentation settings of source code is clearly dumb (would be
a good candidate for a new C++ preprocessor directive :-)).
But I'm pretty sure that folks who have not enjoyed the
benefits of working in an environment with consistent 4-tabs,
actually using tabs in source code, will not immediately grasp
why any of the abovementioned should be dumb. After all, we
manage quite fine without using tabs at all, thank you.

Yes. You shouldn't use tabs in your source code; that much is

Only for cross-platform code. For Windows programming you'd have a very hard
time if you didn't tackle tabs, since MS's code uses them. And since you have to
tackle them anyway, it would be silly to give up the benefits (yes, there are).

 And there's no problem with an editor doing whatever it
wants with the tab key (emacs reindents the line according to
its idea of how it should be indented). The problem is when the
editor (or any other program) inserts a tab character in the
code, or displays an existing tab character as if tab stops were
anything else but 8.

On *nix. In Windows (and presumably on the Mac) the problem is when an editor
displays existing tab characters as if tab stops were anything else but 4. Makes
havoc of the existing code you have to relate to.

If you're using an indentation other than 8 (and 8 is too
big), then you have to use some spaces for the indentation.
(Because people are stupid enough to set tabstops in their
editor at something different than 8, I've given up using
tabs at all in text files. Just spaces, so everyone will
see the code as it was meant to be formatted.)

Using spaces instead of tabs is a good recommendation for
cross-platform work, and it is, for example, the solution
adopted by Boost.

Not just cross platform. It comes into play anytime you do a
diff or whatever Windows equivalent of grep is. (I'll admit
that I'm lazy---rather than learn the Windows tools for such
essential tasks, I just installed a Unix tool kit. Which is far
from ideal, but since I already know it, and don't work enough
under Windows to justify learning anything else...)

Not sure what the imagined problem would be.

Letting the editor indent however much you want (I like four,
but three or five is also acceptable) is also a good thing; just
get everyone on the project to agree. And make sure that when
the indentation gets into the files, it's as spaces, not tab
characters, or you'll run into problems downstream.

Yes, yes, for cross-platform code, certainly.

Since there's no hope of ever convincing *nix folks to give up the stupid 8
positions per tab stop convention, and adopt the much more rational 4. <g>


- Alf

[1] If for nothing else, then because I once edited that article.

A: Because it messes up the order in which people normally read text.
Q: Why is it such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?

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