[PATCH 2/5] pretty: allow formatting names as initials

[Jeff King <peff@peff.net>]

Initials are shorter and often unique enough in a
per-project setting, so they can be used to give a more
informative version of --oneline.

The 'S' in the placeholder is for "short" (and 's' is
already taken by DATE_SHORT), but obviously that's pretty
arcane.

Possibly there should be more customization of initials,
asking for only 2-letter initials, etc.

Signed-off-by: Jeff King <peff@peff.net>
---
When I first tested it with "git log --format=%aS" I had to wonder "who
the heck is ntnd?". So using only the first-and-last would match the git
project's practice better, at least.

 pretty.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/pretty.c b/pretty.c
index c532c17..de62405 100644
--- a/pretty.c
+++ b/pretty.c
@@ -674,6 +674,23 @@ static int mailmap_name(const char **email, size_t *email_len,
 	return mail_map->nr && map_user(mail_map, email, email_len, name, name_len);
 }
 
+static void format_initials(struct strbuf *out, const char *name, size_t len)
+{
+	int initial = 1;
+	size_t i;
+
+	for (i = 0; i < len; i++) {
+		char c = name[i];
+		if (isspace(c)) {
+			initial = 1;
+			continue;
+		}
+		if (initial && isalpha(c))
+			strbuf_addch(out, tolower(c));
+		initial = 0;
+	}
+}
+
 static size_t format_person_part(struct strbuf *sb, char part,
 				 const char *msg, int len,
 				 const struct date_mode *dmode)
@@ -702,6 +719,10 @@ static size_t format_person_part(struct strbuf *sb, char part,
 		strbuf_add(sb, mail, maillen);
 		return placeholder_len;
 	}
+	if (part == 'S') {
+		format_initials(sb, name, namelen);
+		return placeholder_len;
+	}
 
 	if (!s.date_begin)
 		goto skip;
-- 
2.10.0.566.g5365f87