From 7204f08177a638478d828be6ccccbe3c51179b3f Mon Sep 17 00:00:00 2001
From: Dan Buch <dan@meatballhat.com>
Date: Tue, 26 Sep 2023 06:43:22 -0400
Subject: [PATCH] Expressions and starting flow control in RBE

---
 rustbyexample/.gitignore                      |  6 ++---
 rustbyexample/expression.rs                   | 25 +++++++++++++++++++
 rustbyexample/flow_control.d/if_else.rs       | 23 +++++++++++++++++
 rustbyexample/flow_control.d/loop.d/nested.rs | 18 +++++++++++++
 rustbyexample/flow_control.d/loop.d/return.rs | 13 ++++++++++
 rustbyexample/flow_control.d/loop.rs          | 23 +++++++++++++++++
 rustbyexample/flow_control.d/while.rs         | 17 +++++++++++++
 7 files changed, 122 insertions(+), 3 deletions(-)
 create mode 100644 rustbyexample/expression.rs
 create mode 100644 rustbyexample/flow_control.d/if_else.rs
 create mode 100644 rustbyexample/flow_control.d/loop.d/nested.rs
 create mode 100644 rustbyexample/flow_control.d/loop.d/return.rs
 create mode 100644 rustbyexample/flow_control.d/loop.rs
 create mode 100644 rustbyexample/flow_control.d/while.rs

diff --git a/rustbyexample/.gitignore b/rustbyexample/.gitignore
index d591051..307d7d8 100644
--- a/rustbyexample/.gitignore
+++ b/rustbyexample/.gitignore
@@ -1,6 +1,6 @@
-/*.d/*
+*.d/out
+*.d/**/out
+expression
 hello
 primitives
 variable_bindings
-
-!/*.d/*.rs
diff --git a/rustbyexample/expression.rs b/rustbyexample/expression.rs
new file mode 100644
index 0000000..ac421f4
--- /dev/null
+++ b/rustbyexample/expression.rs
@@ -0,0 +1,25 @@
+#[allow(path_statements)]
+#[allow(unused_must_use)]
+fn main() {
+    let x = 5;
+    x;
+    x + 1;
+    15;
+
+    let x = 5u32;
+
+    let y = {
+        let x_squared = x * x;
+        let x_cube = x_squared * x;
+
+        x_cube + x_squared + x
+    };
+
+    let z = {
+        2 * x;
+    };
+
+    println!("x is {:?}", x);
+    println!("y is {:?}", y);
+    println!("z is {:?}", z);
+}
diff --git a/rustbyexample/flow_control.d/if_else.rs b/rustbyexample/flow_control.d/if_else.rs
new file mode 100644
index 0000000..d131213
--- /dev/null
+++ b/rustbyexample/flow_control.d/if_else.rs
@@ -0,0 +1,23 @@
+fn main() {
+    let n = 5;
+
+    if n < 0 {
+        print!("{} is negative", n);
+    } else if n > 0 {
+        print!("{} is positive", n);
+    } else {
+        print!("{} is zero", n);
+    }
+
+    let big_n = if n < 10 && n > -10 {
+        println!(", and is a small number, increase net-fold");
+
+        10 * n
+    } else {
+        println!(", and is a big number, halve the number");
+
+        n / 2
+    };
+
+    println!("{} -> {}", n, big_n);
+}
diff --git a/rustbyexample/flow_control.d/loop.d/nested.rs b/rustbyexample/flow_control.d/loop.d/nested.rs
new file mode 100644
index 0000000..42dab25
--- /dev/null
+++ b/rustbyexample/flow_control.d/loop.d/nested.rs
@@ -0,0 +1,18 @@
+#![allow(unreachable_code)]
+#![allow(unused_labels)]
+
+fn main() {
+    'outer: loop {
+        println!("Entered the outer loop");
+
+        'inner: loop {
+            println!("Entered the inner loop");
+
+            break 'outer;
+        }
+
+        println!("This point will never be reached");
+    }
+
+    println!("Exited the outer loop");
+}
diff --git a/rustbyexample/flow_control.d/loop.d/return.rs b/rustbyexample/flow_control.d/loop.d/return.rs
new file mode 100644
index 0000000..41810b0
--- /dev/null
+++ b/rustbyexample/flow_control.d/loop.d/return.rs
@@ -0,0 +1,13 @@
+fn main() {
+    let mut counter = 0;
+
+    let result = loop {
+        counter += 1;
+
+        if counter == 10 {
+            break counter * 2;
+        }
+    };
+
+    assert_eq!(result, 20);
+}
diff --git a/rustbyexample/flow_control.d/loop.rs b/rustbyexample/flow_control.d/loop.rs
new file mode 100644
index 0000000..e18a6cd
--- /dev/null
+++ b/rustbyexample/flow_control.d/loop.rs
@@ -0,0 +1,23 @@
+fn main() {
+    let mut count = 0u32;
+
+    println!("Let's count until infinity!");
+
+    loop {
+        count += 1;
+
+        if count == 3 {
+            println!("three");
+
+            continue;
+        }
+
+        println!("{}", count);
+
+        if count == 5 {
+            println!("OK, that's enough");
+
+            break;
+        }
+    }
+}
diff --git a/rustbyexample/flow_control.d/while.rs b/rustbyexample/flow_control.d/while.rs
new file mode 100644
index 0000000..38778dc
--- /dev/null
+++ b/rustbyexample/flow_control.d/while.rs
@@ -0,0 +1,17 @@
+fn main() {
+    let mut n = 1;
+
+    while n < 101 {
+        if n % 15 == 0 {
+            println!("fizzbuzz");
+        } else if n % 3 == 0 {
+            println!("fizz");
+        } else if n % 5 == 0 {
+            println!("buzz");
+        } else {
+            println!("{}", n);
+        }
+
+        n += 1;
+    }
+}