[PATCH] coding-style: Allow some use of ternary operators

[Claudio Fontana]

A common sense improvement.

Reviewed-by: Claudio Fontana <cfontana at suse.de>

On 7/25/22 15:13, Michal Privoznik wrote:
> While we all understand that excessive use of ternary operator
> may worsen code readability (e.g. nested, multi-line expression),
> there are few cases where using it actually improves code
> readability. For instance, when a function takes a long list of
> arguments out of which one depends on a boolean expression, or
> when formatting "yes"/"no" or "on"/"off" values based on a
> boolean variable (although one can argue that the latter is a
> subset of the former). Just consider alternatives to:
> 
>   virBufferAsprintf(buf, "<elem>%s</elem>\n", boolVar ? "yes" : "no");
> 
> In fact, this pattern occurs plenty in our code. Exempt if from
> our "no ternary operators" rule.
> 
> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
> ---
>  docs/coding-style.rst | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/docs/coding-style.rst b/docs/coding-style.rst
> index bf0a80fbc5..038f18bda2 100644
> --- a/docs/coding-style.rst
> +++ b/docs/coding-style.rst
> @@ -470,7 +470,9 @@ Pointer comparisons may be shortened. All long forms are okay.
>      if (!foo)                # or: if (foo == NULL)
>  
>  New code should avoid the ternary operator as much as possible.
> -Specifically it must never span more than one line or nest:
> +Specifically it must never span more than one line or nest. However,
> +its usage in very basic cases is warranted (e.g. when deciding
> +between two constant strings):
>  
>  ::
>  
> @@ -481,6 +483,9 @@ Specifically it must never span more than one line or nest:
>  
>      char *foo = bar ? bar->baz ? bar->baz->foo : "nobaz" : "nobar";
>  
> +  GOOD:
> +    virBufferAsprintf(buf, "<element>%s</element>\n", boolVar ? "yes" : "no");
> +
>  Preprocessor
>  ------------
>