From ca812add166befd3e0b6f419114b6777e8847419 Mon Sep 17 00:00:00 2001
From: Dan Buch <dan@meatballhat.com>
Date: Wed, 27 Sep 2023 23:16:10 -0400
Subject: [PATCH] Much more flow control destructuring in RBE

---
 .../destructuring.d/destructure_enum.rs       | 30 +++++++++++++++++++
 .../destructuring.d/destructure_pointers.rs   | 29 ++++++++++++++++++
 .../destructuring.d/destructure_slice.rs      | 27 +++++++++++++++++
 .../destructuring.d/destructure_structures.rs | 19 ++++++++++++
 .../destructuring.d/destructure_tuple.rs      | 12 ++++++++
 rustbyexample/flow_control.d/match.d/guard.rs | 16 ++++++++++
 .../flow_control.d/match.d/guard2.rs          |  9 ++++++
 rustbyexample/flow_control.d/match.rs         | 19 ++++++++++++
 8 files changed, 161 insertions(+)
 create mode 100644 rustbyexample/flow_control.d/match.d/destructuring.d/destructure_enum.rs
 create mode 100644 rustbyexample/flow_control.d/match.d/destructuring.d/destructure_pointers.rs
 create mode 100644 rustbyexample/flow_control.d/match.d/destructuring.d/destructure_slice.rs
 create mode 100644 rustbyexample/flow_control.d/match.d/destructuring.d/destructure_structures.rs
 create mode 100644 rustbyexample/flow_control.d/match.d/destructuring.d/destructure_tuple.rs
 create mode 100644 rustbyexample/flow_control.d/match.d/guard.rs
 create mode 100644 rustbyexample/flow_control.d/match.d/guard2.rs
 create mode 100644 rustbyexample/flow_control.d/match.rs

diff --git a/rustbyexample/flow_control.d/match.d/destructuring.d/destructure_enum.rs b/rustbyexample/flow_control.d/match.d/destructuring.d/destructure_enum.rs
new file mode 100644
index 0000000..fe7020a
--- /dev/null
+++ b/rustbyexample/flow_control.d/match.d/destructuring.d/destructure_enum.rs
@@ -0,0 +1,30 @@
+#[allow(dead_code)]
+enum Color {
+    Red,
+    Blue,
+    Green,
+    RGB(u32, u32, u32),
+    HSV(u32, u32, u32),
+    HSL(u32, u32, u32),
+    CMY(u32, u32, u32),
+    CMYK(u32, u32, u32, u32),
+}
+
+fn main() {
+    let color = Color::RGB(122, 17, 40);
+
+    println!("What color is it?");
+    match color {
+        Color::Red => println!("The color is Red!"),
+        Color::Blue => println!("The color is Blue!"),
+        Color::Green => println!("The color is Green!"),
+        Color::RGB(r, g, b) => println!("Red: {}, green: {}, and blue: {}!", r, g, b),
+        Color::HSV(h, s, v) => println!("Hue: {}, saturation: {}, value: {}!", h, s, v),
+        Color::HSL(h, s, l) => println!("Hue: {}, saturation: {}, lightness: {}!", h, s, l),
+        Color::CMY(c, m, y) => println!("Cyan: {}, magenta: {}, yellow: {}!", c, m, y),
+        Color::CMYK(c, m, y, k) => println!(
+            "Cyan: {}, magenta: {}, yellow: {}, key (black): {}!",
+            c, m, y, k
+        ),
+    }
+}
diff --git a/rustbyexample/flow_control.d/match.d/destructuring.d/destructure_pointers.rs b/rustbyexample/flow_control.d/match.d/destructuring.d/destructure_pointers.rs
new file mode 100644
index 0000000..c49c63f
--- /dev/null
+++ b/rustbyexample/flow_control.d/match.d/destructuring.d/destructure_pointers.rs
@@ -0,0 +1,29 @@
+fn main() {
+    let reference = &4;
+
+    match reference {
+        &val => println!("Got a value via destructuring: {:?}", val),
+    }
+
+    match *reference {
+        val => println!("Got a value via dereferencing: {:?}", val),
+    }
+
+    let _not_a_reference = 3;
+
+    let ref _is_a_reference = 3;
+
+    let value = 5;
+    let mut mut_value = 6;
+
+    match value {
+        ref r => println!("Got a reference to a value: {:?}", r),
+    }
+
+    match mut_value {
+        ref mut m => {
+            *m += 10;
+            println!("We added 10. `mut_value`: {:?}", m);
+        }
+    }
+}
diff --git a/rustbyexample/flow_control.d/match.d/destructuring.d/destructure_slice.rs b/rustbyexample/flow_control.d/match.d/destructuring.d/destructure_slice.rs
new file mode 100644
index 0000000..5fb096a
--- /dev/null
+++ b/rustbyexample/flow_control.d/match.d/destructuring.d/destructure_slice.rs
@@ -0,0 +1,27 @@
+fn main() {
+    let array = [1, -2, 6];
+
+    match array {
+        [0, second, third] => println!("array[0] = 0, array[1] = {}, array[2] = {}", second, third),
+
+        [1, _, third] => println!(
+            "array[0] = 1, array[2] = {} and array[1] was ignored",
+            third
+        ),
+
+        [-1, second, ..] => println!(
+            "array[0] = -1, array[1] = {} and all the other ones were ignored",
+            second
+        ),
+
+        [3, second, tail @ ..] => println!(
+            "array[0] = 3, array[1] = {} and the other elements were {:?}",
+            second, tail
+        ),
+
+        [first, middle @ .., last] => println!(
+            "array[0] = {}, middle = {:?}, array[2] = {}",
+            first, middle, last
+        ),
+    }
+}
diff --git a/rustbyexample/flow_control.d/match.d/destructuring.d/destructure_structures.rs b/rustbyexample/flow_control.d/match.d/destructuring.d/destructure_structures.rs
new file mode 100644
index 0000000..b469e69
--- /dev/null
+++ b/rustbyexample/flow_control.d/match.d/destructuring.d/destructure_structures.rs
@@ -0,0 +1,19 @@
+fn main() {
+    struct Foo {
+        x: (u32, u32),
+        y: u32,
+    }
+
+    let foo = Foo { x: (1, 2), y: 3 };
+
+    match foo {
+        Foo { x: (1, b), y } => println!("First of x is 1, b = {}, y = {}", b, y),
+        Foo { y: 2, x: i } => println!("y is 2, i = {:?}", i),
+        Foo { y, .. } => println!("y = {}, we don't care about x", y),
+    }
+
+    let faa = Foo { x: (1, 2), y: 3 };
+
+    let Foo { x: x0, y: y0 } = faa;
+    println!("Outside: x0 = {x0:?}, y0 = {y0}");
+}
diff --git a/rustbyexample/flow_control.d/match.d/destructuring.d/destructure_tuple.rs b/rustbyexample/flow_control.d/match.d/destructuring.d/destructure_tuple.rs
new file mode 100644
index 0000000..ce8c8c5
--- /dev/null
+++ b/rustbyexample/flow_control.d/match.d/destructuring.d/destructure_tuple.rs
@@ -0,0 +1,12 @@
+fn main() {
+    let triple = (0, -2, 3);
+
+    println!("Tell me about {:?}", triple);
+    match triple {
+        (0, y, z) => println!("First is `0`, `y` is {:?}, and `z` is {:?}", y, z),
+        (1, ..) => println!("First is `1` and the rest doesn't matter"),
+        (.., 2) => println!("last is `2` and the rest doesn't matter"),
+        (3, .., 4) => println!("First is `3`, last is `4`, and the rest doesn't matter"),
+        _ => println!("It doesn't matter what they are"),
+    }
+}
diff --git a/rustbyexample/flow_control.d/match.d/guard.rs b/rustbyexample/flow_control.d/match.d/guard.rs
new file mode 100644
index 0000000..27c90a9
--- /dev/null
+++ b/rustbyexample/flow_control.d/match.d/guard.rs
@@ -0,0 +1,16 @@
+#[allow(dead_code)]
+enum Temperature {
+    Celsius(i32),
+    Fahrenheit(i32),
+}
+
+fn main() {
+    let temperature = Temperature::Celsius(35);
+
+    match temperature {
+        Temperature::Celsius(t) if t > 30 => println!("{}C is above 30 Celsius", t),
+        Temperature::Celsius(t) => println!("{}C is below 30 Celsius", t),
+        Temperature::Fahrenheit(t) if t > 86 => println!("{}F is above 86 Fahrenheit", t),
+        Temperature::Fahrenheit(t) => println!("{}F is below 86 Fahrenheit", t),
+    }
+}
diff --git a/rustbyexample/flow_control.d/match.d/guard2.rs b/rustbyexample/flow_control.d/match.d/guard2.rs
new file mode 100644
index 0000000..49b8684
--- /dev/null
+++ b/rustbyexample/flow_control.d/match.d/guard2.rs
@@ -0,0 +1,9 @@
+fn main() {
+    let number: u8 = 4;
+
+    match number {
+        i if i == 0 => println!("Zero"),
+        i if i > 0 => println!("Greater than zero"),
+        _ => unreachable!("Should never happen."),
+    }
+}
diff --git a/rustbyexample/flow_control.d/match.rs b/rustbyexample/flow_control.d/match.rs
new file mode 100644
index 0000000..4be9d13
--- /dev/null
+++ b/rustbyexample/flow_control.d/match.rs
@@ -0,0 +1,19 @@
+fn main() {
+    let number = 13;
+
+    println!("Tell me about {}", number);
+    match number {
+        1 => println!("One!"),
+        2 | 3 | 5 | 7 | 11 => println!("This is a prime"),
+        13..=19 => println!("A teen"),
+        _ => println!("Ain't special"),
+    }
+
+    let boolean = true;
+    let binary = match boolean {
+        false => 0,
+        true => 1,
+    };
+
+    println!("{} -> {}", boolean, binary);
+}