add practice projects

practices/hello-package/src/back_of_house.rs

@@ -0,0 +1,7 @@
+use crate::front_of_house;
+pub fn fix_incorrect_order() {
+    cook_order();
+    front_of_house::serving::serve_order();
+}
+
+pub fn cook_order() {}

practices/hello-package/src/front_of_house/hosting.rs

@@ -0,0 +1,6 @@
+pub fn add_to_waitlist() {}
+
+pub fn seat_at_table() -> String {
+    String::from("sit down please")
+}
+

practices/hello-package/src/front_of_house/mod.rs

@@ -0,0 +1,2 @@
+pub mod hosting;
+pub mod serving;

practices/hello-package/src/front_of_house/serving.rs

@@ -0,0 +1,9 @@
+pub fn take_order() {}
+
+pub fn serve_order() {}
+
+pub fn take_payment() {}
+
+// Maybe you don't want the guest hearing the your complaining about them
+// So just make it private
+fn complain() {} 

practices/hello-package/src/lib.rs

@@ -0,0 +1,12 @@
+mod front_of_house;
+mod back_of_house;
+
+pub use crate::front_of_house::hosting;
+
+pub fn eat_at_restaurant() -> String {
+    front_of_house::hosting::add_to_waitlist();
+    
+    back_of_house::cook_order();
+
+    String::from("yummy yummy!")
+}

practices/hello-package/src/main.rs

@@ -0,0 +1,4 @@
+fn main() {
+    assert_eq!(hello_package::hosting::seat_at_table(), "sit down please");
+    assert_eq!(hello_package::eat_at_restaurant(),"yummy yummy!");
+}