Add and use generic name->id mapping code for color slot parsing

Instead of hard coding the name-to-id mapping in C code, keep it in an
array and use a common function to do the parsing. This reduces code
and also allows us to list all possible color slots later.

This starts using C99 designated initializers more for convenience
(the first designated initializers have been introduced in builtin/clean.c
for some time without complaints)

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 21 insertions, 32 deletions

diff --git a/diff.c b/diff.c
index 4753170fe1..56d7bfded6 100644
--- a/diff.c
+++ b/diff.c
@@ -69,6 +69,25 @@ static char diff_colors[][COLOR_MAXLEN] = {
 	GIT_COLOR_FAINT_ITALIC,	/* NEW_MOVED_ALTERNATIVE_DIM */
 };
 
+static const char *color_diff_slots[] = {
+	[DIFF_CONTEXT]		      = "context",
+	[DIFF_METAINFO]		      = "meta",
+	[DIFF_FRAGINFO]		      = "frag",
+	[DIFF_FILE_OLD]		      = "old",
+	[DIFF_FILE_NEW]		      = "new",
+	[DIFF_COMMIT]		      = "commit",
+	[DIFF_WHITESPACE]	      = "whitespace",
+	[DIFF_FUNCINFO]		      = "func",
+	[DIFF_FILE_OLD_MOVED]	      = "oldMoved",
+	[DIFF_FILE_OLD_MOVED_ALT]     = "oldMovedAlternative",
+	[DIFF_FILE_OLD_MOVED_DIM]     = "oldMovedDimmed",
+	[DIFF_FILE_OLD_MOVED_ALT_DIM] = "oldMovedAlternativeDimmed",
+	[DIFF_FILE_NEW_MOVED]	      = "newMoved",
+	[DIFF_FILE_NEW_MOVED_ALT]     = "newMovedAlternative",
+	[DIFF_FILE_NEW_MOVED_DIM]     = "newMovedDimmed",
+	[DIFF_FILE_NEW_MOVED_ALT_DIM] = "newMovedAlternativeDimmed",
+};
+
 static NORETURN void die_want_option(const char *option_name)
 {
 	die(_("option '%s' requires a value"), option_name);
@@ -76,39 +95,9 @@ static NORETURN void die_want_option(const char *option_name)
 
 static int parse_diff_color_slot(const char *var)
 {
-	if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
+	if (!strcasecmp(var, "plain"))
 		return DIFF_CONTEXT;
-	if (!strcasecmp(var, "meta"))
-		return DIFF_METAINFO;
-	if (!strcasecmp(var, "frag"))
-		return DIFF_FRAGINFO;
-	if (!strcasecmp(var, "old"))
-		return DIFF_FILE_OLD;
-	if (!strcasecmp(var, "new"))
-		return DIFF_FILE_NEW;
-	if (!strcasecmp(var, "commit"))
-		return DIFF_COMMIT;
-	if (!strcasecmp(var, "whitespace"))
-		return DIFF_WHITESPACE;
-	if (!strcasecmp(var, "func"))
-		return DIFF_FUNCINFO;
-	if (!strcasecmp(var, "oldmoved"))
-		return DIFF_FILE_OLD_MOVED;
-	if (!strcasecmp(var, "oldmovedalternative"))
-		return DIFF_FILE_OLD_MOVED_ALT;
-	if (!strcasecmp(var, "oldmoveddimmed"))
-		return DIFF_FILE_OLD_MOVED_DIM;
-	if (!strcasecmp(var, "oldmovedalternativedimmed"))
-		return DIFF_FILE_OLD_MOVED_ALT_DIM;
-	if (!strcasecmp(var, "newmoved"))
-		return DIFF_FILE_NEW_MOVED;
-	if (!strcasecmp(var, "newmovedalternative"))
-		return DIFF_FILE_NEW_MOVED_ALT;
-	if (!strcasecmp(var, "newmoveddimmed"))
-		return DIFF_FILE_NEW_MOVED_DIM;
-	if (!strcasecmp(var, "newmovedalternativedimmed"))
-		return DIFF_FILE_NEW_MOVED_ALT_DIM;
-	return -1;
+	return LOOKUP_CONFIG(color_diff_slots, var);
 }
 
 static int parse_dirstat_params(struct diff_options *options, const char *params_string,