Add episode 2

posts/2018-05-06-tell-me-a-story-i-could-code.md

@@ -5,7 +5,7 @@ is_draft: false
 data:
   dsq_thread_id: ""
   lang: en
-  author: "Mathieu Nivoliez & Gaetan Baton de Noyer"
+  author: "Mathieu Nivoliez & Gaetan Bayon de Noyer"
   comments: true
   img_cover: ""
 ---

posts/tell-me-a-story-i-could-code-2.md

+title: "Tell me a story I could code #2"
+layout: post.liquid
+is_draft: true
+data:
+  dsq_thread_id: ""
+  lang: en
+  author: "Mathieu Nivoliez & Gaetan Bayon de Noyer"
+  comments: true
+  img_cover: ""
+
+---
+Hello everyone! It's us again, Gaetan and Mathieu!
+This is the second episode of *Tell me a story I could code*.
+At our surprise, the concept worked more than we hope and you, YES YOU, have been very prolific!
+
+We thank the people involved at the end ;)
+
+## "What was proposed?"
+
+In shrot, a movement, a dialog and the appartition of a dragon was proposed.
+Here is how we have proceed.
+
+First, we have now a dragon, which is different from a human, but it is still a character.
+Second, characters can speak to each over.
+Third, we got a sense of location which character can go to or run away from.
+
+So, let's rename our `Character` structure to `Human`:
+```rust
+struct Human {
+  name: String,
+  money: i32,
+}
+```
+
+and then create the `Dragon` struct:
+```rust
+struct Dragon {
+  name: String,
+}
+```
+
+Next step abstract the Character behaviour:
+```rust
+pub trait Character {
+    fn new(name: &str) -> Self;
+
+    fn says_to(&self, other: &Self, msg: &str);
+
+    fn move_to(&self, location: &Self);
+
+    fn get_name(&self) -> &str;
+
+    fn run_away_from(&self, location: &Self);
+}
+```
+But as it, the only `Location` a `Charater` can go to or run From is another `Charater`. So let say that we want `Character` able to do that with a `Localisable` struct.
+
+```rust
+pub trait Localizable {
+    fn get_location(&self) -> String;
+}
+```
+
+We can then adapt the `Character` struct like that to tell that some metho will use a type `T` that `impl`ements `Localizable`:
+
+```rust
+pub trait Character {
+    fn new(name: &str) -> Self;
+
+    fn says_to<T: Character>(&self, other: &T, msg: &str);
+
+    fn move_to<T: Localizable>(&self, location: &T);
+
+    fn get_name(&self) -> &str;
+
+    fn run_away_from<T: Localizable>(&self, location: &T);
+}
+```
+
+Notice that the name inside `Character` was before a `&'static str` (meaning a [`String` slice](https://doc.rust-lang.org/std/primitive.str.html) with a `static` lifetime) and have been change for a `String`. The reason for that it is easier to work with the `String` and do not require to care about the lifetime (the "scope" in which the variable lives) in case we have to return it in a fashion manner. Also, note that using `static` mean that the lifetime of the reference is the same as the application lifetime.
+
+Now the output looks like:
+```bash
+Once upon a time...
+There was a man named Bob.
+Oh 1 penny! " said Bob."
+There was a man named Joe.
+Bob move to Joe
+"Dude! Look what I found!" said Bob to Joe
+"You should invest the penny in the Sheriff of Nottingham's Bank" said Joe to Bob
+"But I already have invested money in the bank, I want to buy a horse!" said Bob to Joe
+There was a dragon named Igorrr.
+Igorrr the dragon fly toward Bob
+"The shiny thing belongs to me" said Igorrr to Bob
+"Never! Founders keepers, you Reptilebug!" said Bob to Igorrr
+```
+
+The full code is available [here](https://gitlab.deep-nope.me/mnivoliez/tell-me-story-i-could-code).
+
+More on:
+* [Slice](https://doc.rust-lang.org/book/second-edition/ch04-03-slices.html)
+* [Trait](https://doc.rust-lang.org/book/second-edition/ch10-02-traits.html)
+* [Lifetime](https://doc.rust-lang.org/book/second-edition/ch10-03-lifetime-syntax.html) 
+
+Special thanks to:
+* Julian Chan
+* Jason C. McDonald
+* Faizan Rabbani
+* Valentin Silvestre
+* Sauban
+* Salim Mahboubi
+from the [dev.to post discussion](https://dev.to/mnivoliez/tell-me-a-story-i-could-code-1ho7/comments) for adding element to the story.
+
+Same as last time, we are counting on you for the follow up :p
+
+--
+Gaetan and Mathieu