[PATCH/GSoC_v3] branch.c: turn nested if-else logic to table-driven

[Yao Zhao <zhaox383@umn.edu>]

Signed-off-by: Yao Zhao <zhaox383@umn.edu>
---
 branch.c | 53 +++++++++++++++++++++++++++++------------------------
 1 file changed, 29 insertions(+), 24 deletions(-)
Hello Eric,

Thank you and Junio for reviewing my code. It is really helpful to improve my code quality.

This is version 3 of patch. Previous address : http://thread.gmane.org/gmane.comp.version-control.git/243919. I do not use positional initializer because it is not allowed to use variable in it. I don't know if it's ok to use this redundant way to initialize "list".

I cannot find -v flag in documentation you indicated in last email so I use set-prefix to add it into prefix.
	
Now I am working on writing proposal for git project. I am really interested in last one, about improve git_config. I know it's important to get known about git_config first and have read documentation about it. But I am really confused about how to understand code of git_config. When user type in git config in terminal, what is the execute order of functions? How git config influence other git command? Does program read config file every time when they execuate config-related command?

Thank you,

Yao

diff --git a/branch.c b/branch.c
index 723a36b..1df30c7 100644
--- a/branch.c
+++ b/branch.c
@@ -53,7 +53,33 @@ void install_branch_config(int flag, const char *local, const char *origin, cons
 	int remote_is_branch = starts_with(remote, "refs/heads/");
 	struct strbuf key = STRBUF_INIT;
 	int rebasing = should_setup_rebase(origin);
-
+	struct print_list {
+		const char *print_str;
+		const char *arg2; 
+		const char *arg3;
+	} ; 
+	struct print_list target;
+
+	struct print_list list[2][2][2];
+	list[0][0][0].print_str = N_("Branch %s set up to track local ref %s.");
+	list[0][0][0].arg2 = remote;
+	list[0][0][1].print_str = N_("Branch %s set up to track local ref %s by rebasing.");
+	list[0][0][1].arg2 = remote;
+	list[0][1][0].print_str = N_("Branch %s set up to track remote ref %s.");
+	list[0][1][0].arg2 = remote;
+	list[0][1][1].print_str = N_("Branch %s set up to track remote ref %s by rebasing.");
+	list[0][1][1].arg2 = remote;
+	list[1][0][0].print_str = N_("Branch %s set up to track local branch %s.");
+	list[1][0][0].arg2 =shortname;
+	list[1][0][1].print_str = N_("Branch %s set up to track local branch %s by rebasing.");
+	list[1][0][1].arg2 = shortname;
+	list[1][1][0].print_str = N_("Branch %s set up to track remote branch %s from %s.");
+	list[1][1][0].arg2 = shortname;
+	list[1][1][0].arg3 = origin;
+	list[1][1][1].print_str = N_("Branch %s set up to track remote branch %s from %s by rebasing.");
+	list[1][1][1].arg2 = shortname;
+	list[1][1][1].arg3 = origin;
+ 
 	if (remote_is_branch
 	    && !strcmp(local, shortname)
 	    && !origin) {
@@ -77,29 +103,8 @@ void install_branch_config(int flag, const char *local, const char *origin, cons
 	strbuf_release(&key);
 
 	if (flag & BRANCH_CONFIG_VERBOSE) {
-		if (remote_is_branch && origin)
-			printf_ln(rebasing ?
-				  _("Branch %s set up to track remote branch %s from %s by rebasing.") :
-				  _("Branch %s set up to track remote branch %s from %s."),
-				  local, shortname, origin);
-		else if (remote_is_branch && !origin)
-			printf_ln(rebasing ?
-				  _("Branch %s set up to track local branch %s by rebasing.") :
-				  _("Branch %s set up to track local branch %s."),
-				  local, shortname);
-		else if (!remote_is_branch && origin)
-			printf_ln(rebasing ?
-				  _("Branch %s set up to track remote ref %s by rebasing.") :
-				  _("Branch %s set up to track remote ref %s."),
-				  local, remote);
-		else if (!remote_is_branch && !origin)
-			printf_ln(rebasing ?
-				  _("Branch %s set up to track local ref %s by rebasing.") :
-				  _("Branch %s set up to track local ref %s."),
-				  local, remote);
-		else
-			die("BUG: impossible combination of %d and %p",
-			    remote_is_branch, origin);
+			target = list[!!remote_is_branch][!!origin][!!rebasing];
+			printf_ln (_(target.print_str), local, target.arg2, target.arg3);
 	}
 }
 
-- 
1.8.3.2