From: Jonathan Nieder <jrnieder@gmail.com>
Date: Sun, 10 Jun 2012 20:22:05 GMT
Subject: Re: [PATCH/RFC] Documenation update: use of braces in if/else if/else chain
Message-ID: <20120610202205.GA2052@burratino>
In-Reply-To: <1339349190-84552-1-git-send-email-muhtasib@gmail.com>

Hi,

Leila Muhtasib wrote:

> --- a/Documentation/CodingGuidelines
> +++ b/Documentation/CodingGuidelines
> @@ -117,9 +117,26 @@ For C programs:
>  
>     is frowned upon.  A gray area is when the statement extends
>     over a few lines, and/or you have a lengthy comment atop of
> -   it.  Also, like in the Linux kernel, if there is a long list
> -   of "else if" statements, it can make sense to add braces to
> -   single line blocks.
> +   it.  Also, like in the Linux kernel, if one of the
> +   "if/else if/else" chain has a multiple statement block, use {}
> +   even for a single statement block in that chain. And "else"
> +   should come on the same line as the closing "}" of its "if" block.

I don't think that's quite accurate.  Current best practice in both
git and the Linux kernel is a little looser than that.

> +
> +	//correct
> +	if (bla) {
> +		x = 1;
> +		...
> +	} else {
> +		x = 2;
> +	}

True.

> +
> +	//incorrect
> +	if (bla) {
> +		x = 1;
> +		...
> +	}
> +	else
> +		x = 2;

Also true.  But:

	/* correct */
	if (bla) {
		x = 1;
		...
	} else
		x = 2;

And:

If you have a long "if" with a one-line "else", consider whether you
are needlessly keeping the reader in suspense about something simple.
It might be more pleasant to read with the exceptional case up front:

	if (!bla) {
		x = 2;
	} else {
		x = 1;
		...
	}

This is especially true when the exceptional case returns or exits.

	if (bla && no_bla)
		return error("--blah and --no-blah cannot be used together");
	x = 1;
	...

Hope that helps,
Jonathan