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authormo8it <mo8it@proton.me>2024-07-05 13:39:50 +0200
committermo8it <mo8it@proton.me>2024-07-05 13:39:50 +0200
commit7123c7ae3a9605fbe962e4ef0a0f1424cd16fef8 (patch)
treec67f7e62bb9a179ae4fdbab492501cb6847e64c7 /exercises/12_options
parent77b687d501771c24bd83294d97b8e6f9ffa92d6b (diff)
parent4d9c346a173bb722b929f3ea3c00f84954483e24 (diff)
Merge remote-tracking branch 'upstream/main' into fix-enum-variant-inconsistency
Diffstat (limited to 'exercises/12_options')
-rw-r--r--exercises/12_options/options1.rs47
-rw-r--r--exercises/12_options/options2.rs19
-rw-r--r--exercises/12_options/options3.rs20
3 files changed, 38 insertions, 48 deletions
diff --git a/exercises/12_options/options1.rs b/exercises/12_options/options1.rs
index e131b48..9964807 100644
--- a/exercises/12_options/options1.rs
+++ b/exercises/12_options/options1.rs
@@ -1,19 +1,13 @@
-// 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 it's before 22:00 (24-hour system), then 5 scoops are left. At 22:00,
+// someone eats it all, so no icecream is left (value 0). Return `None` if
+// `hour_of_day` is higher than 23.
+fn maybe_icecream(hour_of_day: u16) -> Option<u16> {
+ // TODO: Complete the function body.
+}
+
+fn main() {
+ // You can optionally experiment here.
}
#[cfg(test)]
@@ -21,19 +15,22 @@ mod tests {
use super::*;
#[test]
+ fn raw_value() {
+ // TODO: Fix this test. How do you get the value contained in the
+ // Option?
+ let icecreams = maybe_icecream(12);
+
+ assert_eq!(icecreams, 5); // Don't change this line.
+ }
+
+ #[test]
fn check_icecream() {
+ assert_eq!(maybe_icecream(0), Some(5));
assert_eq!(maybe_icecream(9), Some(5));
- assert_eq!(maybe_icecream(10), Some(5));
- assert_eq!(maybe_icecream(23), Some(0));
+ assert_eq!(maybe_icecream(18), Some(5));
assert_eq!(maybe_icecream(22), Some(0));
+ assert_eq!(maybe_icecream(23), Some(0));
+ assert_eq!(maybe_icecream(24), None);
assert_eq!(maybe_icecream(25), None);
}
-
- #[test]
- fn raw_value() {
- // TODO: Fix this test. How do you get at the value contained in the
- // Option?
- let icecreams = maybe_icecream(12);
- assert_eq!(icecreams, 5);
- }
}
diff --git a/exercises/12_options/options2.rs b/exercises/12_options/options2.rs
index 4d998e7..07c27c6 100644
--- a/exercises/12_options/options2.rs
+++ b/exercises/12_options/options2.rs
@@ -1,9 +1,6 @@
-// options2.rs
-//
-// Execute `rustlings hint options2` or use the `hint` watch subcommand for a
-// hint.
-
-// I AM NOT DONE
+fn main() {
+ // You can optionally experiment here.
+}
#[cfg(test)]
mod tests {
@@ -12,7 +9,7 @@ mod tests {
let target = "rustlings";
let optional_target = Some(target);
- // TODO: Make this an if let statement whose value is "Some" type
+ // TODO: Make this an if-let statement whose value is `Some`.
word = optional_target {
assert_eq!(word, target);
}
@@ -23,15 +20,15 @@ mod tests {
let range = 10;
let mut optional_integers: Vec<Option<i8>> = vec![None];
- for i in 1..(range + 1) {
+ for i in 1..=range {
optional_integers.push(Some(i));
}
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.
+ // TODO: Make this a while-let statement. Remember that `Vec::pop()`
+ // adds another layer of `Option`. You can do nested pattern matching
+ // in if-let and while-let statements.
integer = optional_integers.pop() {
assert_eq!(integer, cursor);
cursor -= 1;
diff --git a/exercises/12_options/options3.rs b/exercises/12_options/options3.rs
index 23c15ea..4cedb51 100644
--- a/exercises/12_options/options3.rs
+++ b/exercises/12_options/options3.rs
@@ -1,21 +1,17 @@
-// options3.rs
-//
-// Execute `rustlings hint options3` or use the `hint` watch subcommand for a
-// hint.
-
-// I AM NOT DONE
-
+#[derive(Debug)]
struct Point {
x: i32,
y: i32,
}
fn main() {
- let y: Option<Point> = Some(Point { x: 100, y: 200 });
+ let optional_point = Some(Point { x: 100, y: 200 });
- match y {
- Some(p) => println!("Co-ordinates are {},{} ", p.x, p.y),
- _ => panic!("no match!"),
+ // TODO: Fix the compiler error by adding something to this match statement.
+ match optional_point {
+ Some(p) => println!("Co-ordinates are {},{}", p.x, p.y),
+ _ => panic!("No match!"),
}
- y; // Fix without deleting this line.
+
+ println!("{optional_point:?}"); // Don't change this line.
}