[PATCH v2 07/11] ref-filter: introduce align_atom_parser()

@@ -16,6 +16,11 @@
 
 typedef enum { FIELD_STR, FIELD_ULONG, FIELD_TIME } cmp_type;
 
+struct align {
+	align_type position;
+	unsigned int width;
+};
+
 /*
  * An atom is a valid field atom listed below, possibly prefixed with
  * a "*" to denote deref_tag().

@@ -31,6 +36,7 @@ static struct used_atom {
 	cmp_type type;
 	union {
 		const char *color;
+		struct align align;
 	} u;
 } *used_atom;
 static int used_atom_cnt, need_tagged, need_symref;

@@ -63,6 +69,49 @@ static void color_atom_parser(struct used_atom *atom)
 		die(_("expected format: %%(color:<color>)"));
 }
 
+static align_type parse_align_position(const char *s)
+{
+	if (!strcmp(s, "right"))
+		return ALIGN_RIGHT;
+	else if (!strcmp(s, "middle"))
+		return ALIGN_MIDDLE;
+	else if (!strcmp(s, "left"))
+		return ALIGN_LEFT;
+	return -1;
+}
+
+static void align_atom_parser(struct used_atom *atom)
+{
+	struct align *align = &atom->u.align;
+	const char *buf = NULL;
+	struct strbuf **s, **to_free;
+	int width = -1;
+
+	match_atom_name(atom->str, "align", &buf);
+	if (!buf)
+		die(_("expected format: %%(align:<width>,<position>)"));
+	s = to_free = strbuf_split_str_omit_term(buf, ',', 0);
+
+	align->position = ALIGN_LEFT;
+
+	while (*s) {
+		int position;
+
+		if (!strtoul_ui(s[0]->buf, 10, (unsigned int *)&width))
+			;
+		else if ((position = parse_align_position(s[0]->buf)) > 0)
+			align->position = position;
+		else
+			die(_("unrecognized %%(align) argument: %s"), s[0]->buf);
+		s++;
+	}
+
+	if (width < 0)
+		die(_("positive width expected with the %%(align) atom"));
+	align->width = width;
+	strbuf_list_free(to_free);
+}
+
 static struct {
 	const char *name;
 	cmp_type cmp_type;

@@ -101,17 +150,12 @@ static struct {
 	{ "flag" },
 	{ "HEAD" },
 	{ "color", FIELD_STR, color_atom_parser },
-	{ "align" },
+	{ "align", FIELD_STR, align_atom_parser },
 	{ "end" },
 };
 
 #define REF_FORMATTING_STATE_INIT  { 0, NULL }
 
-struct align {
-	align_type position;
-	unsigned int width;
-};
-
 struct contents {
 	unsigned int lines;
 	struct object_id oid;

@@ -880,35 +924,7 @@ static void populate_value(struct ref_array_item *ref)
 				v->s = " ";
 			continue;
 		} else if (match_atom_name(name, "align", &valp)) {
-			struct align *align = &v->u.align;
-			struct strbuf **s, **to_free;
-			int width = -1;
-
-			if (!valp)
-				die(_("expected format: %%(align:<width>,<position>)"));
-
-			s = to_free = strbuf_split_str_omit_term(valp, ',', 0);
-
-			align->position = ALIGN_LEFT;
-
-			while (*s) {
-				if (!strtoul_ui(s[0]->buf, 10, (unsigned int *)&width))
-					;
-				else if (!strcmp(s[0]->buf, "left"))
-					align->position = ALIGN_LEFT;
-				else if (!strcmp(s[0]->buf, "right"))
-					align->position = ALIGN_RIGHT;
-				else if (!strcmp(s[0]->buf, "middle"))
-					align->position = ALIGN_MIDDLE;
-				else
-					die(_("improper format entered align:%s"), s[0]->buf);
-				s++;
-			}
-
-			if (width < 0)
-				die(_("positive width expected with the %%(align) atom"));
-			align->width = width;
-			strbuf_list_free(to_free);
+			v->u.align = atom->u.align;
 			v->handler = align_atom_handler;
 			continue;
 		} else if (!strcmp(name, "end")) {