[bzalasky]

The things I hate most about CoffeeScript are the dash rockets and white-space significance. These are just opinions though. There are things I like about CS as well, like destructuring assignment and splats. Sometimes when I'm writing JS, I miss is, unless, etc... That said, I'd put my money on ES6 in the long run, though it doesn't really matter. People should use whatever makes them (and their team) happy and productive.

[tiglionabbit]

Significant indentation is a good thing. Haskell and Python do it too.

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?

[vidarh]

Significant indentation is enough for me to avoid Python. It just doesn't have enough to offer vs. the available alternatives without significant indentation.

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.

[tiglionabbit]

I'm not setting up a straw man. I'm saying that it makes more sense if computers and humans are looking for the same things. Since humans read the indentation, computers should read the indentation too.

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.

[ralmidani]

An easy solution to the tab problem is to use spaces instead. A good text editor will even let you use the tab key to insert a set number of spaces.

[tomp]

It's not just significant indentation. CS parses "f + g" differently from "f +g" (the former is an addition, the latter is a function call with "+g" as the first argument).

[tiglionabbit]

Yeah, the unary operators can cause gotchas.

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));

[sangnoir]

I like the indentation + braces redundancy because indentations are for humans, brackets are for the interpreter. Logic blocks are more explicit with brackets

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.

[vertex-four]

> I encountered a non-obvious Python bug that was caused by mixed spaces-and-tabs

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!

[tiglionabbit]

Just installed SublimeLinter. Thanks!

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.

[nothrabannosir]

True, agreed. Python has the -tt flag but, UI mistake, it should have been on by default. Or at least -t.

[marcosdumay]

Python's lambda semantics are limited due to the syntatic limitations created by Python's significant identation. That's not an universal problem of significant identation, but Python's syntax has it. I don't know, CS, so I don't know if it creates any such limitation.

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.

[dragonwriter]

> Python's lambda semantics are limited due to the syntatic limitations created by Python's significant identation.

(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.

[marcosdumay]

> nitpick: you seem to consistently use "identation" in place of "indentation".

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.

[dragonwriter]

> And no, computers don't deal fine with it.

Sure they do.

> To minimise some Python code you need almost an entire Python parser.

I don't think source-to-source transformations requiring a parser for the source is an indication that it is problematic for computers to handle something. I mean, to execute the source code you need a parser, too, and no one says that needing a parser for execution is a sign that computers don't handle a language well.

> Assembling Python code from small pieces (something that is really important for Javascript) is a frightening problem.

Sure, assembling by cut-and-paste is a problem with significant indentation, especially when using media (like the web) which do not respect indentation well.

OTOH, using significant amount of cut-and-paste coding (rather than reuse by library code) is a sign of a problem with the language, development process, and/or execution environment, anyway, so I don't see it as a particular problem that a language structure isn't friendly to copy-paste coding.

[greggman]

I'm sure this has been argued to death but the counter argument is invisible formatting changing behavior is a bad thing. Sure if you get your entire team to use spaces or the same tabs great but passing open source code around to lots of programmers some of which use tabs and some of which use spaces ends up leading to wasted debugging time when someone used a tab where they should have used a space or visa versa.

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;
    }

vs

    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;
    }

On a long functions I find it much easier to see/find/delete the debug print lines by indenting them separate from the real logic but I can't do that on any language that enforces code blocks by indentation.

Commenting out also because an issue

    void SomeFunc(int v) {
       bool doit = v > 5;
       if (doit) 
       {
         DoSomething();
         DoSomethingElse();
         DoSomethingOther();
       }
    }

For testing I often want to comment out the if

    void SomeFunc(int v) {
       bool doit = v > 5;
       //if (doit) 
       {
         DoSomething();
         DoSomethingElse();
         DoSomethingOther();
       }
    }

If I was in python I can't do that

    def SomeFunc(v):
       doit = v > 5
       #if doit 
         DoSomething()
         DoSomethingElse()
         DoSomethingOther()
       

Error! I have to format the whole function just to comment out a line for testing. Yes in this case I could put `if true` (then requiring two changes instead of one) but there are plenty of other cases where code blocks by indent make it really annoying to work with my code.

So no, significant indentation is not a good thing.

[Flimm]

Python 3 does not allow you to mix spaces and tabs. I don't know if Coffeescript is similarly strict.

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.

[vidarh]

I can't stand incorrect indentation either, but my experience is that it regularly happens anyway, and I'd rather not have that break my code.

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.

[acjohnson55]

I want to love whitespace significance, but after hitting refactoring pain points many times in Python, Coffeescript, and Sass/Less/Stylus, at this point I believe the brackets are worth their redundancy.