Tabs vs Spaces

[endolith]

For some strange new definition of the word "solution".

His site and video only cover the somewhat easy cases, and arguably not perfectly. (For instance, note in the video how at 1:28 how the comment on line 11 doesn't move.)

But it's a step in the right direction. Whenever there's a "holy war" over some thing like this, where everyone claims advantages for their "side" and that the other side is categorically wrong, there's actually probably a modern, technical solution that would appease both, but people are too busy criticizing the other alternatives to think of it.

[edge walker]

Tabs for indent. Spaces for alignment.

Amen brother.

[Anpheus]

I don't understand why people are looking to technology to solve that question, when we've pretty well argued this, and the simplest solution is to change your bad habit and make a good one.

[zahlman]

Yay. Got referred here from elsewhere. Hooray for necro-posting!

Unfortunately, not everyone does. There's some people in the one-true-style thread I think who think it should be a heretical 2 spaces.

I am one of them. The people I really don't understand are the ones who want to make it three spaces. Apparently, the author of the forum software is one of them, considering how tabs are converted in code boxes here.

Can we all agree that anybody who mixes tabs and spaces for indentation will spend an eternity burning in hell, though?

I'd like to. Unfortunately, that consigns far too many innocent people who are horribly abused by their IDEs. The people who *really* need to be, shall we say, doing their part to avoid an infernal ice age, are the ones who thought it would be a good idea to implement this when doing the auto-indentation in the IDE (the most common style I've seen is: 4 spaces; 1 tab; 1 tab and 4 spaces; 2 tabs; etc.), presumably to save a few bytes in the source files or something.

Seriously. We're all relative nobodies, and a bunch of people in this thread understand perfectly well how tabs and spaces are supposed to be combined. Why can't we get an editor which behaves this way by default? (Vim has the nasty habit of using mixed tabs and spaces for alignment, even once you've convinced it to use tabs exclusively for indentation.)

I've actually ended up modifying my style to use "indentation instead of alignment where reasonable", like so:

Code: Select all

# I'm using a Python example because my Python code is
# most prone to containing complex *expressions*:
# --> represents a tab
def func(
-->type reallyLongParameterNameOne,
-->type reallyLongParameterNameTwo
):
-->doSomething()
-->x = [
-->-->reallyComplexExpressionOf(thing)
-->-->for thing in funkyGenerator(
-->-->-->reallyLongParameterNameOne
-->-->) if interesting(thing)
-->]


C++ keywords sorted by length:

Somewhat pedantic: "TRUE" and "FALSE" are not C++ keywords. "true" and "false" are.

If someone using an 8-character stop has to deal with lines longer than 80 characters, then too bad; he can just set it to 4-character stops, and you're almost no worse off than if you had used spaces in the first place. (In fact, if this person is editing the code, he'd probably need to change settings anyway if you used spaces, lest he start inserting 8 of them where there should only be 4.) At least with tabs you've given him a choice of (1) not worrying about the 80-col limit, (2) saying that his preference for 8-space tabs overrides his preferences for 80-col limits and leaving the settings the same, and (3) saying his preference for 80-col limits overrides his preferences for 8-space tabs and changing to shorter tabs.

OTOH, if this kind of thing is a problem in practice, it might indicate that the code is simply more complex than it ought to be.

That must sound weird coming from the 2-space-indent guy. But I'm not using that as an excuse for more deeply nested code; it just looks right to me. I don't try to claim it's "right". It's just really really hard for me to imagine staring at really wide indents all the time and processing it OK.

The editor I use converts tabs to spaces. I use 3 spaces per tab, and I don't have to work on anybody else's code, so it's alright....

Aaaugh! It's one of THEM!

Seriously, if the editor takes care of auto-indentation anyway, there is no reason to use a character that doesn't even have a defined width.

You're missing the point. There is a perfectly good reason to use a character that doesn't have a defined width. That reason is: it doesn't have a defined width.

If two people are using this editor, and they want the indentation to be a different amount (and a quick survey of the thread indicates that this is very common), then if the editor has saved tabs to the underlying text file, it only has to adjust the tab stop used for the text control. If it has saved spaces, it has to apply heuristics and convert back and forth (if it doesn't convert both ways from a "reference", then the VCS will get polluted with whitespace changes, and it will also have to know who saved which version of the file in order to know how to convert the spaces). Then we notice that we simplify that code by letting the "reference" use 1 space indent, and actually letting that space be a different character from the spaces used for alignment (so that we don't need the fancy heuristics) - and gee, I wonder what character we'll pick?

[endolith]

I don't understand why people are looking to technology to solve that question, when we've pretty well argued this, and the simplest solution is to change your bad habit and make a good one.

Riiiight...

So which of several conflicting "good habits" should we all adopt?

[Qoppa]

I use vim and have it set up to enter 4 spaces when I press tab. I hate it when my code looks like shit in another editor.

[EvanED]

I am one of them. The people I really don't understand are the ones who want to make it three spaces. Apparently, the author of the forum software is one of them, considering how tabs are converted in code boxes here.

Three is silly, but the correct answer is 4. This is self-evident.

(I don't have a "good" reason for this, I just think it's hard to blur your eyes and get an overview of the code structure, or scroll quickly for a file looking for a particular pattern, with two. Eight I think quickly forces things too the right much. (Even with two levels of indent, you're using 8 more characters than 4; I tend to use longer function, class, and variable names, so I can eat through those 80 characters quickly. I also like lining up corresponding things on subsequent lines, which often "wastes" more space and also prevents line breaks.) So basically, 2 is too few, 8 is too wide. And 3 is an odd number. Four does have the problem that stuff lines up that I don't like: like the line following either an 'if' or a 'for', depending on whether you leave a space after the keyword, will line up with the contents of the parentheses.)

[enk]

Vim has the nasty habit of using mixed tabs and spaces for alignment, even once you've convinced it to use tabs exclusively for indentation.

I have also been bugged by this so I decided to ask the mailinglist. The solution is simply :set copyindent

[Amnesiasoft]

I hate it when my code looks like shit in another editor.

You know why it looks bad? Because you are doing it WRONG! If you used tabs properly, it would look good in any editor.

[Qoppa]

Well no. Sometimes I mix tabs and spaces. For example

Code: Select all

while (x == 1 && y == 2 && z == 3 && w == 4 // ... lots of variables
       somethingelse == 'x') // 1 tab and 3 spaces

As opposed to

Code: Select all

while (x == 1 && y == 2 && z == 3 && w == 4 // ...
    somethingelse == 'x') // 1 tab
// or
while (x == 1 && y == 2 && z == 3 && w == 4 // ...
        somethingelse == 'x') // 2 tabs

[Anpheus]

Why is this topic still here? This is so simple.

Tabs and spaces done right will look good in any editor in any monospaced font.

Code: Select all

if (x... &&
____y || z...

See how that lines up? Those are spaces, four spaces always lines up with four other monospaced characters.

Code: Select all

-tab->if (x... &&
-tab->____y || z...

Still lines up with tabs of equivalent to 6 spaces.

Code: Select all

-tabtab-tab-tab-tabtabtabtab--tabtab->if (x... &&
-tabtab-tab-tab-tabtabtabtab--tabtab->____y || z...

Still lines up whether you use one tab or a dozen tabs of varying spaces as long as they're uniformly applied.


As everyone else has said, for the love of god, tabs for indentation, spaces for alignment, everyone will be happy and your code will look pretty.

[EvanED]

Well no. Sometimes I mix tabs and spaces. For example

Code: Select all

while (x == 1 && y == 2 && z == 3 && w == 4 // ... lots of variables
       somethingelse == 'x') // 1 tab and 3 spaces

As opposed to

This is probably exactly the wrong way to mix tabs and spaces... if someone changes the tab stop to 8, your code now looks like

Code: Select all

while (x==1 ...
           somethingelse == 'x')

or with a tab-width of two characters,

Code: Select all

while (x==1 ...
     somethingelse == 'x')

In both cases, the "something else" is no longer aligned with the x==1. It's this sort of thing that cause a lot of people to say that you shouldn't use tabs because changing the indent size can mess up the code.

[masher]

The editor I use converts tabs to spaces. I use 3 spaces per tab, and I don't have to work on anybody else's code, so it's alright....

Aaaugh! It's one of THEM!

I have changed. I still use 3 spaces, but I don't convert tabs.

I use tabs for indenting and spaces for alignment.

[Qoppa]

Well no. Sometimes I mix tabs and spaces. For example

Code: Select all

while (x == 1 && y == 2 && z == 3 && w == 4 // ... lots of variables
       somethingelse == 'x') // 1 tab and 3 spaces

As opposed to

This is probably exactly the wrong way to mix tabs and spaces... if someone changes the tab stop to 8, your code now looks like...

Except when I press tab, 4 spaces are inserted. So it's going to be 7 spaces, 0 tabs in any editor. But I still press tab, which is why I'm saying tab... Using only spaces (which is what I do) is no doubt the safest route to go.

[Anpheus]

Those aren't tabs then, that's your editor using spaces instead of tabs.

Which is just going to annoy other developers who have their own preferences on how wide a tab should be.

[Qoppa]

Which is just going to annoy other developers who have their own preferences on how wide a tab should be.

It's my code damnit! If I want one tab to be four spaces, then dag nabbit, one tab will be four spaces.

[Anpheus]

It's not a tab though, you've got spaces there.

[Qoppa]

It's not a tab though, you've got spaces there.

Yes, and? I'm using the word tab to refer to an indent. It's a tad ambiguous, I know...

[Anpheus]

This is religious wars and the topic is "Tabs vs Spaces," so if you want to argue about what is and is not a tab, this is the right place.

But I think back when character codes were standardized, tabs and spaces weer decreed to be different things and assigned different codes.

[Qoppa]

In that case, let me reword my previous statement.

I use only spaces. Nothing else. Tabs are for squares.

[headprogrammingczar]

I use Eclipse and the first thing I do with an opened file is press ctrl+shift+f. HAHA!

[Berengal]

I use Eclipse and the first thing I do with an opened file is press ctrl+shift+f. HAHA!

Ditto. The only problem is with read-only files, which eclipse won't even write to in the text buffer. This causes a problem with the java stl, as it contains mixed tabs and spaces everywhere. Sometimes it's a tab, sometimes four spaces, sometimes eight spaces... It's horrible, and the indentation makes no sense for any tab width.

[sakeniwefu]

Do you realize the amount of bytes you are wasting using spaces in place of tabs!? By a conservative estimate, a mean average of 6 extra useless bytes per line! You could even be doing multi-line conditions and function calls and putting spaces between expressions. What's next, comments?
What do you think you are coding in, Visual Basic? It's C, people, it's supposed to be unreadable, we only use tabs because code looks cooler that way, but that's as far as artistic licenses go.

[Anpheus]

Your argument might have been valid back when my great grandparents had to etch bits into stone tablets in Sanskrit, but today you can buy billions of bits for less than a dollar.

[EvanED]

I'm pretty sure that was sarcasm

[Anpheus]

And my great grandparents really did write code on stone tablets

[Wiglaf]

I still have the "my precious cycles! my precious bits!" reflex.
I guess its because the counter-argument is terrible: "Oh, because we have big mighty computers, go ahead and waste resources instead of searching for the elegant solution." Have they considered, perhaps, that a lot of little waste stacked up == big waste?

(on-topic "So my vote is in with tabs. But really, who would use an editor that can't auto format according to good indenting practice?")

[Berengal]

Sometimes the elegant solution is one wasting time and space. Of course, the elegance of it might in turn save you time and space elsewhere.

What I'm trying to say is that I've seen python programs run as fast as their c equivalents, because they weren't bogged down by poor algorithms caused by the programmers lack of overview

[GameFreak]

Spaces make my delete key bleed.

[hotaru]

Spaces make my delete key bleed.

then perhaps you should get a better editor.

[GameFreak]

Spaces make my delete key bleed.

then perhaps you should get a better editor.

I mean when I have to make changes without an ide.

[hotaru]

Spaces make my delete key bleed.

then perhaps you should get a better editor.

I mean when I have to make changes without an ide.

ed, se, vi, etc.

[TheOrangeMan]

I'm kind of in the middle about this one. I like the idea of tabs better conceptually, but I often end up wanting to align things a little more precisely, so I usually end up using spaces to avoid mixing the two.

[MHD]

1 press on the tab key = 4 spaces.

PERIOD!

[enk]

I usually prefer my tabs to be tabs, four spaces wide. But when I started writing some assembly, regular old-school eight space tabs came in handy:

Code: Select all

get_input:
        leal    -8(%ebp), %eax
        pushl   %eax
        pushl   $formatstring
        call    scanf
        addl    $8, %esp


Btw. the Google C++ style guide says use two spaces per indent level (may be connected with their 80 char line limit). Who does that, besides Google?

[stephentyrone]

Btw. the Google C++ style guide says use two spaces per indent level (may be connected with their 80 char line limit). Who does that, besides Google?

I used to. It comes in handy if you're writing a lot of spaghetti code (not sure what this says about Google).

[ash.gti]

I do, I have soft tabs that are 2 wide. No reason to waste space.

for me

Code: Select all

def a b, c, e, f
  if e
    s = f - e
  else
    s = f
  end
  b - c
end


isn't that different from

Code: Select all

def a b, c, e, f
    if e
        s = f - e
    else
        s = f
    end
    b - c
end


I don't need 8/4 spaces for each tab, thats just wasted space I could be filling with more code.

[enk]

I don't need 8/4 spaces for each tab, thats just wasted space I could be filling with more code.

But sometimes when you have more consecutive lines per level than in your example, you need a bigger offset to properly disinguish them, I find.

[ash.gti]

So do you mean like when you run into

Code: Select all

def foo(bar):
  fooz = bar
  barz = fooz
  barz(fooz)
  another
  another
  if 1:
    another
    another
    another


vs

Code: Select all

def foo(bar):
    fooz = bar
    barz = fooz
    barz(fooz)
    another
    another
    if 1:
        another
        another
        another


[enk]

So do you mean like when you run into [...]

Yeah.. I tried many sizes (even wrote a vim function to set an arbitrary size from 1 to 8 at a single keypress) but always returned to four as the best compromise.