Add modify to habitmgr.

src/habitmgr.rs

@@ -74,7 +74,7 @@ impl HabitMgr
 		self.habits = serde_json::from_reader(habits_reader).unwrap();
 	}
 
-	fn write_habits(&self)
+	fn export_habits(&self)
 	{
 		let habits_file = OpenOptions::new()
 			.truncate(true)
@@ -95,7 +95,7 @@ impl HabitMgr
 	{
 		self.import_habits();
 		self.habits.push(Habit::new(name.clone(), bad, weight));
-		self.write_habits();
+		self.export_habits();
 
 		println!("New habit {} added.", &name);
 	}
@@ -104,10 +104,32 @@ impl HabitMgr
 	{
 		self.import_habits();
 		let old_habit = self.habits.remove(id);
-		self.write_habits();
+		self.export_habits();
 		println!("Removed habit {}", old_habit.get_name());
 	}
 
+	pub fn modify(&mut self, id:usize,
+						 name:Option<String>,
+						 bad:Option<bool>,
+						 weight:Option<u8>,
+						 _days:Option<String>)
+	{
+		self.import_habits();
+		if name.is_some()
+		{
+			self.habits[id].set_name(name.unwrap());
+		}
+		if bad.is_some()
+		{
+			self.habits[id].set_bad(bad.unwrap());
+		}
+		if weight.is_some()
+		{
+			self.habits[id].set_weight(weight.unwrap());
+		}
+		self.export_habits();
+	}
+
 	pub fn list(&mut self, _all:bool, _verbose:bool)
 	{
 		self.import_habits();