--- a/rust/src/config.rs	Tue Feb 07 22:35:29 2017 +0800
+++ b/rust/src/config.rs	Tue Feb 07 22:57:29 2017 +0800
@@ -68,45 +68,25 @@
         toml::to_string(self).unwrap()
     }
 
-
     pub fn merge(&self, conf: &str) -> Result<Self, String>{
-        println!("config {}", conf);
+        // convert existing and new toml into tables, combine them.
         let mut new_toml = try!(toml::from_str(conf).map_err(|e| e.to_string()));
         let mut ex_val = toml::Value::try_from(self).unwrap();
         let mut ex_toml = ex_val.as_table_mut().unwrap();
         ex_toml.append(&mut new_toml);
         let ret: Self = toml::Value::Table(ex_toml.clone()).try_into().unwrap();
-        return Ok(ret)
-
-
-        /*
-        let mut p = toml::Parser::new(&conf);
-        let p =
-        p.parse()
-            .ok_or_else(|| {
-                format!("toml parsing failed: {:?}", p.errors)
-            })
-            .map(|mut new_toml| {
-                let mut e = toml::Encoder::new();
-                self.serialize(&mut e).unwrap(); // XXX what could go wrong?
-                let mut ex_toml = e.toml;
-                ex_toml.append(&mut new_toml);
-                let mut dec = toml::Decoder::new(toml::Value::Table(ex_toml));
-                Self::deserialize(&mut dec).unwrap() // could this go wrong?
-            })
-            */
+        Ok(ret)
     }
 
     pub fn merge_file(&self, filename: &str) -> Result<Self, String>{
 
         let r = File::open(filename)
-            .map_err(|e| e.to_string())
             .and_then(|mut f| {
                 let mut s = String::new();
                 f.read_to_string(&mut s)
-                    .map_err(|e| e.to_string())
                     .map(|_| s)
-            });
+            })
+            .map_err(|e| e.to_string());
 
         r.and_then(|s| {
             self.merge(&s)