Subject: Re: [PATCH 1/2] log-tree: make format_decorations more flexible

From: Junio C Hamano <[email-masked]>
Date: Thu, 11 Sep 2014 15:39:55 -0700

Harry Jeffery <[email-masked]> writes:

> The prefix, separator and suffix for decorations are hard-coded. Make
> format_decorations more flexible by having the caller specify the
> prefix, separator and suffix.
>
> Signed-off-by: Harry Jeffery <[email-masked]>
> ---
>  log-tree.c | 16 +++++++++-------
>  log-tree.h |  2 +-
>  pretty.c   |  2 +-
>  3 files changed, 11 insertions(+), 9 deletions(-)
>
> diff --git a/log-tree.c b/log-tree.c
> index 95e9b1d..860694c 100644
> --- a/log-tree.c
> +++ b/log-tree.c
> @@ -184,9 +184,11 @@ static void show_children(struct rev_info *opt,
> struct commit *commit, int abbre
>   */
>  void format_decorations(struct strbuf *sb,
>  			const struct commit *commit,
> -			int use_color)
> +			int use_color,
> +			const char* prefix,
> +			const char* sep,
> +			const char* suffix)

In our codebase, please make asterisks stick to the variable not the
type, i.e.

	const char *prefix,
        const char *separator,
        const char *suffix)

Was there a reason why "sep" alone needed to be abbreviated?

>  	if (!decoration)
>  		return;
> -	prefix = " (";
> +	strbuf_addstr(sb, prefix);
>  	while (decoration) {
>  		strbuf_addstr(sb, color_commit);
> -		strbuf_addstr(sb, prefix);
>  		strbuf_addstr(sb, decorate_get_color(use_color, decoration->type));
>  		if (decoration->type == DECORATION_REF_TAG)
>  			strbuf_addstr(sb, "tag: ");
>  		strbuf_addstr(sb, decoration->name);
> +		if(decoration->next)

Have SP between the control statement (i.e. not a function name) and
its opening parenthesis, i.e.

		if (decoration->next)

> +			strbuf_addstr(sb, sep);
>  		strbuf_addstr(sb, color_reset);
> -		prefix = ", ";
>  		decoration = decoration->next;
>  	}

Hmph.  I was kind of found of the nice trick to use a punctuation,
which first points at the prefix " (" and then later points at the
separator ", ", to allow the code that prefixes the punctuation
before showing a new item.  It is now lost.

>  	strbuf_addstr(sb, color_commit);
> -	strbuf_addch(sb, ')');
> +	strbuf_addstr(sb, suffix);
>  	strbuf_addstr(sb, color_reset);
>  }
>
> @@ -221,7 +223,7 @@ void show_decorations(struct rev_info *opt, struct
> commit *commit)
>  		printf("\t%s", (char *) commit->util);
>  	if (!opt->show_decorations)
>  		return;
> -	format_decorations(&sb, commit, opt->diffopt.use_color);
> +	format_decorations(&sb, commit, opt->diffopt.use_color, " (", ", ", ")");
>  	fputs(sb.buf, stdout);
>  	strbuf_release(&sb);
>  }
> diff --git a/log-tree.h b/log-tree.h
> index d6ecd4d..4816911 100644
> --- a/log-tree.h
> +++ b/log-tree.h
> @@ -13,7 +13,7 @@ int log_tree_diff_flush(struct rev_info *);
>  int log_tree_commit(struct rev_info *, struct commit *);
>  int log_tree_opt_parse(struct rev_info *, const char **, int);
>  void show_log(struct rev_info *opt);
> -void format_decorations(struct strbuf *sb, const struct commit
> *commit, int use_color);
> +void format_decorations(struct strbuf *sb, const struct commit
> *commit, int use_color, const char* prefix, const char* sep, const

Linewrapped by your MUA, perhaps?

Again, please check where your asterisks are.

> char* suffix);
>  void show_decorations(struct rev_info *opt, struct commit *commit);
>  void log_write_email_headers(struct rev_info *opt, struct commit *commit,
>  			     const char **subject_p,
> diff --git a/pretty.c b/pretty.c
> index 44b9f64..e4dc093 100644
> --- a/pretty.c
> +++ b/pretty.c
> @@ -1195,7 +1195,7 @@ static size_t format_commit_one(struct strbuf
> *sb, /* in UTF-8 */
>  		return 1;
>  	case 'd':
>  		load_ref_decorations(DECORATE_SHORT_REFS);
> -		format_decorations(sb, commit, c->auto_color);
> +		format_decorations(sb, commit, c->auto_color, " (", ", ", ")");

My eyes hurt staring at this line and the same one in the other
file, trying to see which comma is which.

I wonder if doing something like this once at a single place:

#define format_decorations_std(strbuf, commit, color) \
		format_decorations((strbuf), (commit), (color), " (", ", ", ")")

and using

	format_decorations_std(sb, commit, opt->diffopt.use_color);
	format_decorations_std(sb, commit, c->auto_color);

or even better, name the one that takes three extra parameters as
format_decorations_extended(), and keep the behaviour of the
original one the same, i.e.

	#define format_decorations(strbuf, commit, color) \
		format_decorations_extended((strbuf), (commit), (color), " (", ", ", ")")

That way you do not have to touch the original callers, nor you
would have to worry about breaking any topic that somebody else may
be preparing that adds new calls to format_decorations().

>  		return 1;
>  	case 'g':		/* reflog info */
>  		switch(placeholder[1]) {