Complete options exercises

exercises/options/options1.rs

@@ -1,16 +1,20 @@
 // options1.rs
 // Execute `rustlings hint options1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 // This function returns how much icecream there is left in the fridge.
 // If it's before 10PM, there's 5 pieces left. At 10PM, someone eats them
 // all, so there'll be no more left :(
 fn maybe_icecream(time_of_day: u16) -> Option<u16> {
     // We use the 24-hour system here, so 10PM is a value of 22 and 12AM is a value of 0
     // The Option output should gracefully handle cases where time_of_day > 23.
-    // TODO: Complete the function body - remember to return an Option!
-    ???
+
+    if time_of_day > 24 {
+        None
+    } else if time_of_day >= 22 {
+        Some(0)
+    } else {
+        Some(5)
+    }
 }
 
 #[cfg(test)]
@@ -28,8 +32,7 @@ mod tests {
 
     #[test]
     fn raw_value() {
-        // TODO: Fix this test. How do you get at the value contained in the Option?
-        let icecreams = maybe_icecream(12);
+        let icecreams = maybe_icecream(12).unwrap();
         assert_eq!(icecreams, 5);
     }
 }

exercises/options/options2.rs

@@ -1,8 +1,6 @@
 // options2.rs
 // Execute `rustlings hint options2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 #[cfg(test)]
 mod tests {
     #[test]
@@ -10,8 +8,7 @@ mod tests {
         let target = "rustlings";
         let optional_target = Some(target);
 
-        // TODO: Make this an if let statement whose value is "Some" type
-        word = optional_target {
+        if let word = optional_target.unwrap() {
             assert_eq!(word, target);
         }
     }
@@ -27,9 +24,8 @@ mod tests {
 
         let mut cursor = range;
 
-        // TODO: make this a while let statement - remember that vector.pop also adds another layer of Option<T>
         // You can stack `Option<T>`s into while let and if let
-        integer = optional_integers.pop() {
+        while let Some(Some(integer)) = optional_integers.pop() {
             assert_eq!(integer, cursor);
             cursor -= 1;
         }

exercises/options/options3.rs

@@ -1,8 +1,6 @@
 // options3.rs
 // Execute `rustlings hint options3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 struct Point {
     x: i32,
     y: i32,
@@ -11,7 +9,7 @@ struct Point {
 fn main() {
     let y: Option<Point> = Some(Point { x: 100, y: 200 });
 
-    match y {
+    match &y {
         Some(p) => println!("Co-ordinates are {},{} ", p.x, p.y),
         _ => panic!("no match!"),
     }