Code Style (日本語)

Introduction

"Every second spent enforcing code style is a waste of time". -- Someone, at some point

Status: FALSE

When I encounter really pretty code in the open-source world (and the closed-source world for that matter), I'm a lot more confident that the software has real quality. Of course, from case to case, this may actually not be true, and the style might lie to me, but the important thing is that it appears to have high quality to people. On the other hand, if I encounter code which appears to be shit (although it might really be of excellent quality), it's tempting for me to try and find some alternative. So while enforcing code style might technically be a waste of time, it's psychologically. Also, if you ever intend to use LÖVE as a reference when applying for a job (I've done that), there is a slight chance they will take a ten second look on the code. Even if they are advanced enough to evaluate the code properly, they will not be immune to good (nor bad) style.

Therefore, because I'm such a fucking drone, I'm going to refactor some code here and there (or everywhere) to make things more beautiful. And since I'm potentially fucking up everything anyway, I thought we could decide on a coding style that the majority likes. It's unlikely that we all agree on everything ... but hopefully everyone will accept the decision of the majority.

Namespaces

Namespace 本文の字下げはしないでください。

推奨:

namespace love
{
namespace graphics
{

class Foo
{
public:
  /* ... */
};

} // graphics
} // love

禁止:

  
namespace love
{
  namespace graphics
  {

      class Foo
      {
      public:
          /* ... */
      };

  } // graphics
} // love

クラス宣言

先頭一文字目の英字は大文字にしてください。

推奨:

class Foo
{
};

禁止:

class foo
{
};

class FOO
{
};

ブロックの可視性は徐々に狭くなる順にしてください。

見てわかる通り最初に "API" があることは意味のあることです。これは、通常において読者がとにかく最初に知りたいことであるからです。

推奨:

class Foo
{
public:
protected:
private:
};

禁止:

class Foo
{
private:
protected:
public:
};

多重継承では、各クラスは別々の行に記述してください。

各行はコロンまたはカンマで始めてください。私の経験において、これが diff コマンドと ifdeffery に関して最も柔軟性があるスタイルです。

推奨:

class Foo : public Bar
{
};

class Foo
  : public Bar
  , public Foz
{
};

禁止:

class Foo : public Bar, public Foz
{
};

初期化指定子リスト

継承リストと同様に、初期化指定子は別々の行に記述してください。

推奨:

Foo::Foo()
  : bar(0)
  , foo(1)
{
}

禁止:

Foo::Foo() : bar(0) , foo(1)
{
}

関数・メソッド

関数およびメソッドにはキャメルケースを使用してください。

推奨:

int doomFist(int where);

禁止:

int DoomFist(int where);
int doom_fist(int where);

括弧は間にスペースを挟まず名前の直後に記述してください。

推奨:

int doomFist(int where);

禁止:

int doomFist (int where);

開括弧の直後および閉括弧の直前には余計なスペースを記述しないでください。

推奨:

int doomFist(int where);

禁止:

int doomFist( int where );

One-liners like getters and setters can be inlined in the class declaration. (More-than-one-liners should however not be inlined).

推奨:

class Foo
{
public:
  void setBar(int bar) { this->bar = bar; }
  int getBar() const { return bar; }
private:
  int bar;
};

非推奨:

class Foo
{
public:
  void setBar(int bar);
  int getBar() const;
private:
  int bar;
};

void Foo::setBar(int bar)
{
  this->bar = bar;
}

int Foo::getBar() const
{
  return bar;
}

制御ブロック

制御ブロックはキーワードと式括弧の間を空けて記述してください。これは関数呼び出しからの制御文を視覚的に区別しやすくするためのです。

推奨:

if (foo)
  /* ... */;

禁止:

if(foo)
  /* ... */;

可能であれば、通常は括弧を省略してください (縦方向の空間を残しておくためです)。

推奨:

if (foo)
  bar();

禁止:

if (foo)
{
  bar();
}

推奨:

if (foo)
  bar();
else
{
  foz();
  baz();
}

禁止:

if (foo)
{
  bar();
}
else
{
  foz();
  baz();
}

括弧は次行に記述してください。

推奨:

if (foo)
{
  bar1();
  bar2();
}

禁止:

if (foo) {
  bar1();
  bar2();
}

Pointer affinity

For pointers and references, the asterisk/ampersand should appear next to the variable name.

This makes it consistent with dereferencing (*foo), and is preferred by most LÖVE devs.

推奨:

int *foo;
int &bar;

禁止:

int* foo;
int& bar;

int * foo;
int & bar;

推奨:

int *get_int_ptr();
int &get_int_ref();

禁止:

int* get_int_ptr();
int& get_int_ref();

int * get_int_ptr();
int & get_int_ref();

Spaces vs Tabs

I personally prefer tabs, but I know I'm the only person in the world. We will probably end up with spaces, in which case I suggest 4 spaces per level.

EDIT: I was wrong, everyone (who has so far given a damn) has preferred tabs. In that case, let me specify a more advanced indentation guideline for the truly l33t, hardcore, and handsome.

MIXED TABS AND SPACES (*monocle pops*)

Use tabs for normal indentation.

I.e. when indicating scope.

推奨:

if (foo)
{
<tab>bar();
}

禁止:

if (foo)
{
<space><space><space><space>bar();
}

Use spaces for alignment.

If you really want to align stuff, then the important thing to keep in mind is that the alignment should not break if the viewer is using a tab-size that's different from yours. So, in this example, we're aligning stuff:

if (foo)
{
    int a_var      = 1;
    int anoter_var = 2;
    int moar       = 3;
    int doom       = 4;
}

推奨:

if (foo)
{
<tab>int a_var<space * 6>= 1;
<tab>int anoter_var<space>= 2;
<tab>int moar<space * 7>= 3;
<tab>int doom<space * 7>= 4;
}

禁止:

if (foo)
{
<tab>int a_var<tab * 2>= 1;
<tab>int anoter_var<tab>= 2;
<tab>int moar<tab * 2>= 3;
<tab>int doom<tab * 2>= 4;
}

However, use alignment sparingly, because it makes a lot of diff noise when you add something that's longer than the currently longest thing, and you have to realign everything. So the best option is actually:

Trailing whitespace

Trim all trailing whitespace.

Tabs and spaces before a newline character increase the noise in commits and the source code.

推奨:

<tab>foo();

<tab>bar();

禁止:

<tab>foo();
<tab>
<tab>bar();

Documentation blocks

Asterisks should be aligned vertically.

推奨:

/**
 * Short description.
 *
 * @param foo The foo that goes in the bar.
 * @param bar The bar the foo foes into.
 */
int foz(int foo, int& bar);

禁止:

/**
* Short description.
*
* @param foo The foo that goes in the bar.
* @param bar The bar the foo foes into.
*/
int foz(int foo, int& bar);

If you agree to this, and you also agree that we're using tabs. You're agreeing that tabs and spaces be mixed (although in a very defined way). For a function declaration that's indented one block, you would type something like:

 <tab>/**
 <tab><space>* Short description.
 <tab><space>*
 <tab><space>* Long description.
 <tab><space>*/

#includes

システムインクルードではないものはダブルクォートを使用してください。

推奨:

#include "common/config.h"

禁止:

#include <common/config.h>

キャスト

C スタイルのキャストを使用してください。

C スタイルのキャストを使用しているときに何のために何をしているのかを忘れないようにしてください。

推奨:

Foo *foo = (Foo *) bar;

禁止:

Foo *foo = (Foo*)bar;
Foo *foo = (Foo*) bar;
Foo *foo = (Foo *)bar;

null 文

NULL または 0 よりも nullptr にしてください。

推奨:

foo = nullptr;
bar = nullptr;

禁止:

foo = NULL;
bar = 0;