rust : wip.

dev/lang/rust/enum.md

@@ -0,0 +1,31 @@
+# Emun.
+
+# Create.
+
+```rust
+enum Message {
+  Quit,
+  Echo(String),
+  Move { x: i32, y: i32 },
+  ChangeColor(i32, i32, i32)
+}
+
+impl Message {
+  fn call(&self) {
+    println!("{:?}", self);
+  }
+}
+
+fn main() {
+  let messages = [
+    Message::Move { x: 10, y: 30 },
+    Message::Echo(String::from("hello world")),
+    Message::ChangeColor(128, 16, 32),
+    Message::Quit
+  ];
+
+  for message in &messages {
+    message.call();
+  }
+}
+```

dev/lang/rust/struct.md

@@ -0,0 +1,88 @@
+# Struct.
+
+# Types.
+
+## Classic.
+
+```rust
+struct ColorClassicStruct {
+  red:   i32,
+  green: i32,
+  blue:  i32,
+}
+```
+
+```rust
+let mut green = ColorClassicStruct {
+  red:   0,
+  green: 255,
+  blue:  0,
+}
+
+green.red = green.blue;
+```
+
+## Tuple.
+
+Have no field names.
+
+```rust
+struct Point(i32, i32, i32);
+
+let x = Point(0, 0, 0);
+```
+
+## Unit-like.
+
+Have nothing. TODO: add use-cases.
+
+```rust
+struct AlwaysEqual;
+
+let subject = AlwaysEqual;
+```
+
+# Shortcuts.
+
+## Field-init.
+
+Copy values with the same name.
+
+```rust
+fn create_color(red: i32, green: i32, blue: i32) -> ColorClassicStruct {
+  ColorClassicStruct {
+    red,
+    green,
+    blue,
+  }
+}
+```
+
+## Struct update.
+
+Copy the rest of the struct.
+
+```rust
+let color2 = ColorClassicStruct {
+  red: 255,
+  ..color1
+};
+```
+
+# Logic.
+
+You can write logic in structs.
+
+```rust
+struct Package {
+  sender_country:    String,
+  recipient_country: String,
+  fee: u32
+}
+
+impl Package {
+  fn is_international(&self) -> bool {
+    self.sender_country != self.recipient_country
+  }
+}
+```

dev/lang/rust/vector.md

@@ -23,3 +23,13 @@ for (item in vector.iter_mut()) {} // Mutable iterate.
 ```rust
 vector.iter().map(|element| {}).collect()
 ```
+
+# Copy.
+
+## Clone.
+
+You can clone a Vec in cases when you need to modify a copy.
+
+```rust
+foo(vector.clone())
+```