Difference between revisions of "CodingConventions"

Coding Conventions

This page lists the coding conventions actually in use within Glob2. The intended purpose is to have coherent-looking code through the project. Sorry if this different to your usual conventions.

Indentation

Code should be indented by tabs. A tab should be equivalent to 4 spaces. Please note that in the code below, non-breaking spaces are used because tabs don't display correctly in web pages.

Class and struct naming

Classes should begin with capitals, new words should be denoted by a capital, and words should not be separated by underscores or dashes. In other words,

class TotoIsMyFriend { }; // correct

instead of:

class toto_is_my_friend{}; // wrong

Class members, variables, and C function follow the same convention but without the initial capital:

void totoIsMyFriend(void); // correct

instead of:

void Toto-is-my-friend(void); // wrong

Bracket placement

Brackets {} should be placed alone on a line, except if there is no or only one function call within them.

class Toto
{
    int i;
    void totoIsMyFriend(void) { return i; };
}; // correct

instead of:

class Toto {
    int i;
    void Toto-is-my-friend(void) {
        return i;
    };
}; // wrong

Emacs

If you use Emacs as your editor, you can make it apply these rules to Globulation 2 files by putting the following in the .emacs file in your home directory:

(defconst glob2-c-style
 '((c-basic-offset	. 4)
   (c-offsets-alist            . ((substatement-open . 0)
				   (inline-open	. 0)
				   ))
   )
 "Globulation 2 programming style")

;; Customizations for all modes in CC Mode.
(defun glob2-c-mode-common-hook ()
 (c-add-style "glob2" glob2-c-style)
 )

(add-hook 'c-mode-common-hook 'glob2-c-mode-common-hook)

And adding the following to the top line of each of your source files:

/* emacs settings information: -*- mode: c++; tab-width: 4; c-file-style: "glob2"; -*- */

Proposed Conventions

This section discusses proposals for programming style rules that have not yet been widely accepted

Counting

When referring to the total number of items of a particular type that there are, the current rule is to use numberOfFoo. I find this confusing, as I expect numberOfFoo to refer to the index number of a particular instance of foo. Some alternatives include:

• fooCount
• fooTotal
• fooSize

fooCount seems the easiest to read of the three, fooTotal also makes sense, and fooSize, while confusing, mirrors the foo.size() convention used in STL containers.

By extension, where there is an ordered list of things (most likely an enum), we should always have the following definitions:

enum foo { foo1, foo2, ... fooN };
static const int foo_min = foo1;
static const int foo_max = fooN;
static const int foo_count = foo_max - foo_min + 1;

Getting and setting

At present, it's standard to get values with getFoo() and set them with setFoo(value). While this is clear, it doesn't fit with the C++ convention of using foo() and foo(value). It also doesn't distinguish between the cases where we are supposed to think of getFoo() and setFoo() as simple wrappers around private variables vs. where we should expect more significant processing to be done. I propose that we use getFoo() only where the user should expect significant processing to be done. For example, GAGCore::getFilename() searches an entire list of directories for a file, whereas debugLevel() just sets an internal variable.