6 ms·

NYTimes Objective–C Style Guide

80 points by tater 13y ago

srik 13y ago
> Asterisks indicating pointers belong with the variable, i.e. NSString text not NSString text or NSString * text, except in the case of global string constants. I know I have it wrong, but I always feel that the the variable is of type "pointer to type" so isnt it fairer to have the asterisk paired with the type denoting it is of the kind "pointer to type"?
- Tiktaalik 13y ago
  I've previously shared your opinion on this issue as well, but the first answer to this StackOverflow question shows one good reason why one should opt for having the asterisk touching the variable. http://stackoverflow.com/questions/2452335/asterisk-sometimes-on-variable-type-sometimes-on-variable-name-why http://stackoverflow.com/questions/2452335/asterisk-sometime...
- cobbal 13y ago
  My take on this has always been the pointerness is semantically part of the type, but syntactically it belongs with the variable. Therefore I annoy both parties by putting a space on either side to protest the fact that everyone is wrong.
- davidkclark 13y ago
  It's pretty easy to convince yourself that "* with the type" is wrong when you see this: int* a, b; // a is int* but b is int
  - w0utert 13y ago
    Bingo, that's the exact reason to pair the asterisk with the variable name. Especially in C-family languages where you can actually end up with code that compiles and even works, until it breaks. Think pointer arithmetic on something you assume is a pointer to a signed integer...
- deleted 13y ago
  [deleted]
- wiml 13y ago
  C has a sort of declaration-by-example syntax. You're declaring that *someVar has type NSString. (IMHO, thinking of it this way also makes more complex declarations like function-pointer types, types with qualifiers, etc., easier to read.)
- thought_alarm 13y ago
  You don't have it wrong. In an object-oriented context, whether you're working in C, C++, or Obj-C, it is entirely reasonable to attach the asterisk to the type name, and treat `MyObject* ` as a type. For every weird little edge case where `MyObject* ` doesn't make sense, there are hundreds of examples where it makes complete sense. I've been doing it that way since I started in the 90s, and I've always felt the people who do it the old way (attaching the asterisk to the variable name) are either holding on to an obsolete bit of antique C style, or they don't know what they're doing. It has no place in modern object-oriented code. So what about `int* a, b, c;`? Never declare multiple variables on one line like this.
- masklinn 13y ago
  That's how it feels, but the syntax for declaring multiple variables breaks it: int* a, b; is equivalent to int *a; int b; not int *a; int *b; So while I think it makes sense to think of the pointer nature as part of the type I stopped using it as the risk of writing incorrect code was too great. Though there's also the option of forbidding shorthand declaration. Then you can write int* a; int* b; especially if you have a linter letting you add such a syntax rule.
  - SeanLuke 13y ago
    Given the numerous advantages of int* a; rather than int a;, and the general laziness of declaring variables together anyway, wouldn't it be more reasonable, as a house style, to require int and to disapprove the declaration of multiple variables in the same statement?
    - masklinn 13y ago
      Sure. And as I noted, you may even be able to configure your linter of choice to handle that automatically. There's also the macro option, I guess.
    - w0utert 13y ago
      Note: using % instead of * below because I can't for the life of me figure out how to type an asterisk without it being used as an italics markup directive. >> Given the numerous advantages of int% a; rather than int %a; Care to elaborate what 'numerous advantages' there are to use int% a instead of int %a, because I can't think of a single one besides 'it feels more natural', which IMO is irrelevant in the context of a coding style. Enforcing a single line for each variable declaration does not sound like a good idea, in mathematical code this can quickly grow unwieldy due when lots of variable are involved. It also often makes sense to group declarations of related variables on the same line to indicate they are used in the same way, for example 'int v0i, v1i' to indicate two vertex indices.
      - deleted 13y ago
        [deleted]
- foxhill 13y ago
  i used to think like you do, but this changed my mind; int *a; is saying, when you dereference a, you have an integer. and when you think about it - a pointer is the same length for any data type, even pointers to functions, so it would be pointless to have a different pointer type for each data structure.
  - 0x09 13y ago
    > a pointer is the same length for any data type, even pointers to functions No that's not guaranteed despite being common. And function pointers are not even guaranteed to be representable by void* (POSIX08 does mandate it though.) Relevant sections of the standard here http://stackoverflow.com/a/3941867/1546653 http://stackoverflow.com/a/3941867/1546653
adamnemecek 13y ago
It's strange that NYT seems to be transitioning to a full blown tech company. Good strange though.
- matthewbischoff 13y ago
  It's fun working here during the transition.
hudibras 13y ago
Here's their blog post about it: http://open.blogs.nytimes.com/2013/08/01/objectively-stylish/ http://open.blogs.nytimes.com/2013/08/01/objectively-stylish...
- 5teev 13y ago
  Tag line: "All the Code That’s Fit to printf()"
  - mlchild 13y ago
    NSLog(@"All the code that's fit to NSLog()");
valtron 13y ago
Why do so many style guides mandate spaces for indentation?
- jyap 13y ago
  It is consistent across different editors. Deterministic layout view. Tabs are non deterministic as it depends on user settings.
  - masklinn 13y ago
    Plus not all tools can ignore whitespace changes (so indentation changes everywhere intermixed with actual code changes drown the code stuff), and if your codebase mixes whitespace-significant and whitespace-insignificant code...
- chc 13y ago
  Mainly it's that you don't want to mix both spaces and tabs — you want to use one or the other for a given file or else the indentation will be an incoherent mess from one machine to the next — and it's easier and more compatible to standardize on spaces than tabs.
- vvhn 13y ago
  the right way to use tabs (tabs for indentation, spaces for alignment) needs some amount of discipline to get right always. It's more flexible but very easy to make a mistake and mess it up.
  - valtron 13y ago
    Agreed. But doesn't it take discipline to follow a coding convention in general? I'd argue learning tabs-indent/spaces-align is easier than following most other semantic conventions (e.g. what constitutes a good name, how to organize code).
- gte910h 13y ago
  Python really gets murderously difficult to debug in an organization with multiple types of indentation. Spaces are the least easy to screw up there, and has been why many guides I've seen have "spaces" instead of "tabs" as the default.
calhoun137 13y ago
I hate absurdly long variable names like this: static const NSTimeInterval NYTArticleViewControllerNavigationFadeAnimationDuration = 0.3; I feel like if your naming convention forces you to have variable names over 50 letters long, there is a problem.
- 5teev 13y ago
  Objective-C's tendency to long names (variables, selectors, classes) makes it more "self-documenting" than any language I've worked with. Besides, it's not that bad with autocomplete.
  - Groxx 13y ago
    Now if only that autocomplete would passively infer the current project prefix + (super)class name, so you wouldn't have to type it when it's "local"...
  - blub 13y ago
    With Xcode it's just as bad as it looks. If you have multiple names with the same prefix you have to type it all or scroll in a list to select the correct item. It even fails to complete types like NSString correctly when part of a method call. Not always of course, just when it gets confused, and then I have to delete and type again because the case is wrong.
    - chrisdevereux 13y ago
      Or press tab to get a partial completion and use the arrow keys to pick the right one?
  - taspeotis 13y ago
    I'm not an Objective-C native, but every time I write Objective-C it feels like I'm writing a short story. applicationDidLoad:withANotification:iWonderWhatTheWeatherTodayIs:LetsAskSiri:
    - 13y ago
HaloZero 13y ago
why not provide a post-commit hook enforcing a lot these styles?
- matthewbischoff 13y ago
  We've got some people here working on it.
frr149 13y ago
I see a lot of obsession with the irrelevant: when you're allowed to use dot-notation, number of spaces for indentation (sic), etc... The only reasonable item, it the singleton one, the rest... what a waste of time!
- rimantas 13y ago
  Yeah, there is no value in consistency.
justincormack 13y ago
They seem to have an en dash between Objective and C which made me misparse the title. Surely that's not in their style guide?
- matthewbischoff 13y ago
  Fixed. Thanks for reporting that.
stigi 13y ago
Has anyone ever tried to configure uncriustify [0] with a complex style guide like this and succeeded? Are there other similar tools that might be a better fit? [0] - http://uncrustify.sourceforge.net http://uncrustify.sourceforge.net

80 points by tater 13y ago

srik 13y ago

> Asterisks indicating pointers belong with the variable, i.e. NSString text not NSString text or NSString * text, except in the case of global string constants. I know I have it wrong, but I always feel that the the variable is of type "pointer to type" so isnt it fairer to have the asterisk paired with the type denoting it is of the kind "pointer to type"?

Tiktaalik 13y ago
I've previously shared your opinion on this issue as well, but the first answer to this StackOverflow question shows one good reason why one should opt for having the asterisk touching the variable. http://stackoverflow.com/questions/2452335/asterisk-sometimes-on-variable-type-sometimes-on-variable-name-why http://stackoverflow.com/questions/2452335/asterisk-sometime...
cobbal 13y ago
My take on this has always been the pointerness is semantically part of the type, but syntactically it belongs with the variable. Therefore I annoy both parties by putting a space on either side to protest the fact that everyone is wrong.
davidkclark 13y ago
It's pretty easy to convince yourself that "* with the type" is wrong when you see this: int* a, b; // a is int* but b is int
- w0utert 13y ago
  Bingo, that's the exact reason to pair the asterisk with the variable name. Especially in C-family languages where you can actually end up with code that compiles and even works, until it breaks. Think pointer arithmetic on something you assume is a pointer to a signed integer...
deleted 13y ago
[deleted]
wiml 13y ago
C has a sort of declaration-by-example syntax. You're declaring that *someVar has type NSString. (IMHO, thinking of it this way also makes more complex declarations like function-pointer types, types with qualifiers, etc., easier to read.)
thought_alarm 13y ago
You don't have it wrong. In an object-oriented context, whether you're working in C, C++, or Obj-C, it is entirely reasonable to attach the asterisk to the type name, and treat `MyObject* ` as a type. For every weird little edge case where `MyObject* ` doesn't make sense, there are hundreds of examples where it makes complete sense. I've been doing it that way since I started in the 90s, and I've always felt the people who do it the old way (attaching the asterisk to the variable name) are either holding on to an obsolete bit of antique C style, or they don't know what they're doing. It has no place in modern object-oriented code. So what about `int* a, b, c;`? Never declare multiple variables on one line like this.
masklinn 13y ago
That's how it feels, but the syntax for declaring multiple variables breaks it: int* a, b; is equivalent to int *a; int b; not int *a; int *b; So while I think it makes sense to think of the pointer nature as part of the type I stopped using it as the risk of writing incorrect code was too great. Though there's also the option of forbidding shorthand declaration. Then you can write int* a; int* b; especially if you have a linter letting you add such a syntax rule.
- SeanLuke 13y ago
  Given the numerous advantages of int* a; rather than int a;, and the general laziness of declaring variables together anyway, wouldn't it be more reasonable, as a house style, to require int and to disapprove the declaration of multiple variables in the same statement?
  - masklinn 13y ago
    Sure. And as I noted, you may even be able to configure your linter of choice to handle that automatically. There's also the macro option, I guess.
  - w0utert 13y ago
    Note: using % instead of * below because I can't for the life of me figure out how to type an asterisk without it being used as an italics markup directive. >> Given the numerous advantages of int% a; rather than int %a; Care to elaborate what 'numerous advantages' there are to use int% a instead of int %a, because I can't think of a single one besides 'it feels more natural', which IMO is irrelevant in the context of a coding style. Enforcing a single line for each variable declaration does not sound like a good idea, in mathematical code this can quickly grow unwieldy due when lots of variable are involved. It also often makes sense to group declarations of related variables on the same line to indicate they are used in the same way, for example 'int v0i, v1i' to indicate two vertex indices.
    - deleted 13y ago
      [deleted]
foxhill 13y ago
i used to think like you do, but this changed my mind; int *a; is saying, when you dereference a, you have an integer. and when you think about it - a pointer is the same length for any data type, even pointers to functions, so it would be pointless to have a different pointer type for each data structure.
- 0x09 13y ago
  > a pointer is the same length for any data type, even pointers to functions No that's not guaranteed despite being common. And function pointers are not even guaranteed to be representable by void* (POSIX08 does mandate it though.) Relevant sections of the standard here http://stackoverflow.com/a/3941867/1546653 http://stackoverflow.com/a/3941867/1546653

adamnemecek 13y ago

It's strange that NYT seems to be transitioning to a full blown tech company. Good strange though.

matthewbischoff 13y ago
It's fun working here during the transition.

hudibras 13y ago

Here's their blog post about it: http://open.blogs.nytimes.com/2013/08/01/objectively-stylish/ http://open.blogs.nytimes.com/2013/08/01/objectively-stylish...

5teev 13y ago
Tag line: "All the Code That’s Fit to printf()"
- mlchild 13y ago
  NSLog(@"All the code that's fit to NSLog()");

valtron 13y ago

Why do so many style guides mandate spaces for indentation?

jyap 13y ago
It is consistent across different editors. Deterministic layout view. Tabs are non deterministic as it depends on user settings.
- masklinn 13y ago
  Plus not all tools can ignore whitespace changes (so indentation changes everywhere intermixed with actual code changes drown the code stuff), and if your codebase mixes whitespace-significant and whitespace-insignificant code...
chc 13y ago
Mainly it's that you don't want to mix both spaces and tabs — you want to use one or the other for a given file or else the indentation will be an incoherent mess from one machine to the next — and it's easier and more compatible to standardize on spaces than tabs.
vvhn 13y ago
the right way to use tabs (tabs for indentation, spaces for alignment) needs some amount of discipline to get right always. It's more flexible but very easy to make a mistake and mess it up.
- valtron 13y ago
  Agreed. But doesn't it take discipline to follow a coding convention in general? I'd argue learning tabs-indent/spaces-align is easier than following most other semantic conventions (e.g. what constitutes a good name, how to organize code).
gte910h 13y ago
Python really gets murderously difficult to debug in an organization with multiple types of indentation. Spaces are the least easy to screw up there, and has been why many guides I've seen have "spaces" instead of "tabs" as the default.

calhoun137 13y ago

I hate absurdly long variable names like this: static const NSTimeInterval NYTArticleViewControllerNavigationFadeAnimationDuration = 0.3; I feel like if your naming convention forces you to have variable names over 50 letters long, there is a problem.

5teev 13y ago
Objective-C's tendency to long names (variables, selectors, classes) makes it more "self-documenting" than any language I've worked with. Besides, it's not that bad with autocomplete.
- Groxx 13y ago
  Now if only that autocomplete would passively infer the current project prefix + (super)class name, so you wouldn't have to type it when it's "local"...
- blub 13y ago
  With Xcode it's just as bad as it looks. If you have multiple names with the same prefix you have to type it all or scroll in a list to select the correct item. It even fails to complete types like NSString correctly when part of a method call. Not always of course, just when it gets confused, and then I have to delete and type again because the case is wrong.
  - chrisdevereux 13y ago
    Or press tab to get a partial completion and use the arrow keys to pick the right one?
- taspeotis 13y ago
  I'm not an Objective-C native, but every time I write Objective-C it feels like I'm writing a short story. applicationDidLoad:withANotification:iWonderWhatTheWeatherTodayIs:LetsAskSiri:
  - 13y ago

HaloZero 13y ago

why not provide a post-commit hook enforcing a lot these styles?

matthewbischoff 13y ago
We've got some people here working on it.

frr149 13y ago

I see a lot of obsession with the irrelevant: when you're allowed to use dot-notation, number of spaces for indentation (sic), etc... The only reasonable item, it the singleton one, the rest... what a waste of time!

rimantas 13y ago
Yeah, there is no value in consistency.

justincormack 13y ago

They seem to have an en dash between Objective and C which made me misparse the title. Surely that's not in their style guide?

matthewbischoff 13y ago
Fixed. Thanks for reporting that.

stigi 13y ago

Has anyone ever tried to configure uncriustify [0] with a complex style guide like this and succeeded? Are there other similar tools that might be a better fit? [0] - http://uncrustify.sourceforge.net http://uncrustify.sourceforge.net