Consolidate naming of member variables

[SirVer]

We use m_var, _var and var_ for member variables in various places. We should consolidate this to one: var_.

_var is just as short and is similar to python, however this might clash with reserved variables in the global scope (see http://stackoverflow.com/questions/228783/what-are-the-rules-about-using-an-underscore-in-a-c-identifier). m_var is 1 character longer than the other suggestions.

[GunChleoc (gunchleoc)]

How do we wish to call function arguments then? There is this example in the Google style guide:

class MyClass {
 public:
  ...
  int num_entries() const { return num_entries_; }
  void set_num_entries(int num_entries) { num_entries_ = num_entries; }

 private:
  int num_entries_;
};

but it will cause a "declaration of ‘num_entries’ shadows a member of 'this'" warning in the compiler for the setter function.

[SirVer (sirver)]

I think the warning is great since you should really not reuse a similar name in an argument. For setters (like in your example) I always use value:

  void set_num_entries(int value) { num_entries_ = value; }

[GunChleoc (gunchleoc)]

I also think the warning is great - it has saved me from a bug or two already methinks.

Your idea works great for setters, but I just thought of another use case - what about constructors, where we have more than one argument that we need to name? The conflict here will be between the getter function name and the argument name. We have solved a few of these in the code base by adding _ at the end or the argument, which we will now use for the member variables instead.

[SirVer (sirver)]

For structs (where you are not using anything to separate members) I always use init_<name> in the constructor.

[Klaus Halfmann (klaus-halfmann)]

I started to work on this, but this looks like a ... longer story :-)

[SirVer (sirver)]

Is this not mechanical?

for i in $(find . -name '*.cc' -or -name '*.h'); do
   sed -i s/\bm_([a-zA-z0-9_]+)/\1_/g;
end

[SirVer (sirver)]

Well, that was a bad attempt, but this should get you really close:

for i in $(find . -name '*.cc' -or -name '*.h'); do
  echo $i;
  cat $i | perl -pe 's/\bm_([a-zA-Z0-9_]+)/\1_/g' > $i.tmp;
  mv $i.tmp $i;
done

[GunChleoc (gunchleoc)]

Found another old naming convention in ui_basic/window.h:

private:
 bool _is_minimal;
 uint32_t _oldh; // if it is, this is the old height
 bool _dragging, _docked_left, _docked_right, _docked_bottom;
 int32_t _drag_start_win_x, _drag_start_win_y;
 int32_t _drag_start_mouse_x, _drag_start_mouse_y;

_is_minimal should be is_minimal_ etc.

[SirVer (sirver)]

These are especially bad since identifiers starting with _ are by the c++ standard reserved identifiers that compiler vendors can define and must not be used in regular code.

> Am 07.02.2016 um 06:53 schrieb GunChleoc <email address hidden>:
>
> Found another old naming convention in ui_basic/window.h:
>
> private:
> bool _is_minimal;
> uint32_t _oldh; // if it is, this is the old height
> bool _dragging, _docked_left, _docked_right, _docked_bottom;
> int32_t _drag_start_win_x, _drag_start_win_y;
> int32_t _drag_start_mouse_x, _drag_start_mouse_y;
>
> _is_minimal should be is_minimal_ etc.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1395278
>
> Title:
> Consolidate naming of member variables
>
> Status in widelands:
> Confirmed
>
> Bug description:
> We use m_var, _var and var_ for member variables in various places. We
> should consolidate this to one: var_.
>
> _var is just as short and is similar to python, however this might
> clash with reserved variables in the global scope (see
> http://stackoverflow.com/questions/228783/what-are-the-rules-about-
> using-an-underscore-in-a-c-identifier). m_var is 1 character longer
> than the other suggestions.
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/widelands/+bug/1395278/+subscriptions

[GunChleoc (gunchleoc)]

panel.h also needs fixing - it has a bunch of these, and 2 s_ names for static variables.

I'd like to take care of the logic dir, map_io and game_io. These are pretty intertwined, so using the automated script will give us either a bunch of compiler errors or a huge diff. So, I will refactor those with QTCreator.

[GunChleoc (gunchleoc)]

Fixed in build19-rc1.