Re: [PATCH v2] Teach git diff about Objective-C syntax

["Jonathan del Strother" <maillist@steelskies.com>]

On Wed, Oct 1, 2008 at 12:46 AM, Jonathan del Strother
<jon.delStrother@bestbefore.tv> wrote:
> Add support for recognition of Objective-C class & instance methods, C functions, and class implementation/interfaces.
>
> Signed-off-by: Jonathan del Strother <jon.delStrother@bestbefore.tv>
> ---
> This version is much the same, but rebuilt on top of 1883a0d3b to use the extended regexp stuff, and it doesn't attempt to tidy up other patterns.
>
>  Documentation/gitattributes.txt |    2 ++
>  diff.c                          |   10 ++++++++++
>  2 files changed, 12 insertions(+), 0 deletions(-)
>
> diff --git a/Documentation/gitattributes.txt b/Documentation/gitattributes.txt
> index 2ae771f..2694559 100644
> --- a/Documentation/gitattributes.txt
> +++ b/Documentation/gitattributes.txt
> @@ -315,6 +315,8 @@ patterns are available:
>
>  - `java` suitable for source code in the Java language.
>
> +- `objc` suitable for source code in the Objective-C language.
> +
>  - `pascal` suitable for source code in the Pascal/Delphi language.
>
>  - `php` suitable for source code in the PHP language.
> diff --git a/diff.c b/diff.c
> index b001d7b..3694602 100644
> --- a/diff.c
> +++ b/diff.c
> @@ -1429,6 +1429,16 @@ static const struct funcname_pattern_entry builtin_funcname_pattern[] = {
>          "!^[ \t]*(catch|do|for|if|instanceof|new|return|switch|throw|while)\n"
>          "^[ \t]*(([ \t]*[A-Za-z_][A-Za-z_0-9]*){2,}[ \t]*\\([^;]*)$",
>          REG_EXTENDED },
> +       { "objc",
> +         /* Negate C statements that can look like functions */
> +         "!^[ \t]*(do|for|if|else|return|switch|while)\n"
> +         /* Objective-C methods */
> +         "^[ \t]*([-+][ \t]*\\([ \t]*[A-Za-z_][A-Za-z_0-9* \t]*\\)[ \t]*[A-Za-z_].*)$\n"
> +         /* C functions */
> +         "^[ \t]*(([ \t]*[A-Za-z_][A-Za-z_0-9]*){2,}[ \t]*\\([^;]*)$\n"
> +         /* Objective-C class/protocol definitions */
> +         "^(@(implementation|interface|protocol)[ \t].*)$",
> +         REG_EXTENDED },
>        { "pascal",
>          "^((procedure|function|constructor|destructor|interface|"
>                "implementation|initialization|finalization)[ \t]*.*)$"
> --


Given Brandon's "strip newline (and cr) from line before pattern
matching" patch, the objective C line could be changed to
"^[ \t]*([-+][ \t]*\\([ \t]*[A-Za-z_][A-Za-z_0-9* \t]*\\)[
\t]*[A-Za-z_][A-Za-z_0-9:{()*& \t]*)$\n"
to be more specific about what's allowed to occur on a method line.
Depends how often we really care about getting the funcname right -
for instance, do we want to deal with cases like :

-(void)doStuff:(NSString*)foo {    // TODO : This is a %@^$#@ method
name, change it.

?   I suspect the additional complexity that would be added to the
regex isn't worth the small gain - any thoughts?