It's much easier to read indentation than it is to match up pairs of brackets in your head. In other languages, if the indentation doesn't match the brackets, you'll naturally read the indentation first and get the wrong impression of what the code does. In those languages, the indentation is supposed to match the brackets anyway. Why be redundant like that?
It's much easier to read indentation than unindented/badly indented pairs of brackets, but you're setting up a strawman - it's not either or - and then you tear down the strawman yourself by pointing out we match the indentation anyway.
My code generally is properly indented and has start/end markers (though I mostly write Ruby, so rarely brackets), but what makes me stay away from significant indentation is that in the 30+ years I've been coding, I've never gone long without coming across situations where indentation has broken "in transit" e.g. with cut and paste between systems in annoying ways, or someone loading the code into an editor that butchers the indentation with tabs using "non-standard" tab settings.
When that happens, I'd rather "get the wrong impression" than have the code be broken.
That's one reason I want redundancy. My tools can trivially and automatically fix the result of breaking indentation when the indentation can be derived from the code.
Additionally, I want the visual redundancy, much like I find it far more comfortable to read syntax highlighted code even though it conveys no additional information.
The way things are in bracketed languages, humans and computers read different things, and you just have to hope that they always match up. Sometimes they don't, and the human and computer will have a misunderstanding. To make it a real linguistic redundancy, like in Spanish, the compiler should read both and issue a warning if the indentation is incorrect or misleading. As it is, you and the computer are actually speaking different languages.
Also, here's a gotcha I've run into where `a(b)` is considered different from `a (b)`
x a(b), c # => x(a(b), c);
x a (b), c # => x(a(b, c));
I encountered a non-obvious Python bug that was caused by mixed spaces-and-tabs: to my human eyes, the indentation looked fine - the same as previous line, but the interpreter saw a different level of indentation.
This is why PEP8 exists and people are supposed to follow it. Additionally, mixed spaces-and-tabs is a bug that causes poor readability - there's plenty of people who have their editors set to have tabstops as 2 or 3 spaces rather than 4, and your code will look wrong in their editors.
If you think there's any issues with mixed tabs and spaces in your codebase, Python provides a tool to find out - tabnanny. Additionally, any context-aware code editor will display a warning. (If you're using Sublime Text, the plugin to use is SublimeLinter - I assume there's similar tools for vim and emacs.) You can even set spaces and tabs to display differently in many editors!
It puts some icons in the margins, but I can't figure out how to get an explanation of those icons. I see a bunch of !s next to my import statements.
Also, computers don't deal well with it. It's a smaller problem than people don't dealing well with it (the alternative), but it's still a problem. Anyway, this is much more relevant to scripts that run inside a browser.
(nitpick: you seem to consistently use "identation" in place of "indentation".)
I'm pretty sure that plenty of proposals consistent with Python's significant indentation have been proposed; python's lambda syntax is limited due to the BDFL not being convinced of the utility of more capable lambdas over using named functions enough to want to make Python's syntax more complicated to achieve it.
> Also, computers don't deal well with it.
Computers deal fine with it.
Consequence of English not being my first language, and "indentation" being way too similar in it. I just can't spot the change.
I've seen a couple of proposals, yes they'd work, but they seem to be always ugly. But the problem is not that significant indentation makes it hard to create lambdas (Haskell's ones, for example are fine), but that it's hard to think about rules that won't create some kind of problem. On Python it's lambdas, on Haskell it's that they are often actually harder to write than explicit blocks (good thing Haskell has explicit blocks too).
And no, computers don't deal fine with it. To minimise some Python code you need almost an entire Python parser. Assembling Python code from small pieces (something that is really important for Javascript) is a frightening problem.
On top of that I find it invaluable to be able to space out debugging code. Example
void SomeFunc() {
int x = doSomething1(1, 2, 3, 4);
int y = doSomething1(4, 5, 6, 8);
int z = doSomething1(5, 6, 7, 9);
printf("xyz=%d,%d,%d", x, y, z);
int a = doSomething1(0, 2, 3, 4);
int b = doSomething1(1, 5, 6, 8);
int c = doSomething1(2, 6, 7, 9);
printf("abc=%d,%d,%d", a, b, c);
int d = doSomething1(6, 2, 3, 4);
int e = doSomething1(5, 5, 6, 8);
int f = doSomething1(7, 6, 7, 9);
printf("def=%d,%d,%d", d, e, f);
return x * y * z + a * b * c + d * e * f;
}
void SomeFunc() {
int x = doSomething1(1, 2, 3, 4);
int y = doSomething1(4, 5, 6, 8);
int z = doSomething1(5, 6, 7, 9);
printf("xyz=%d,%d,%d", x, y, z);
int a = doSomething1(0, 2, 3, 4);
int b = doSomething1(1, 5, 6, 8);
int c = doSomething1(2, 6, 7, 9);
printf("abc=%d,%d,%d", a, b, c);
int d = doSomething1(6, 2, 3, 4);
int e = doSomething1(5, 5, 6, 8);
int f = doSomething1(7, 6, 7, 9);
printf("def=%d,%d,%d", d, e, f);
return x * y * z + a * b * c + d * e * f;
}
Commenting out also because an issue
void SomeFunc(int v) {
bool doit = v > 5;
if (doit)
{
DoSomething();
DoSomethingElse();
DoSomethingOther();
}
}
void SomeFunc(int v) {
bool doit = v > 5;
//if (doit)
{
DoSomething();
DoSomethingElse();
DoSomethingOther();
}
}
def SomeFunc(v):
doit = v > 5
#if doit
DoSomething()
DoSomethingElse()
DoSomethingOther()
So no, significant indentation is not a good thing.
I guess you've developed a habit where you're completely OK with having incorrect indentation a lot of the time, whereas I can't stand it. Just because it's easier to read for you doesn't make it easier for everyone, especially beginners.
And "incorrect indentation" has a very different meaning when the indentation is purely for presentation: As illustrated above, some people like to use the indentation to call out specific aspects of the code. That may be "incorrect" from Python perspective, but it is a way of visually providing additional information that is not available to you if you use a language that requires a specific indenting style.