Completed exercise up to Traits

exercises/12_options/options1.rs

@@ -3,7 +3,22 @@
 // someone eats it all, so no ice cream is left (value 0). Return `None` if
 // `hour_of_day` is higher than 23.
 fn maybe_ice_cream(hour_of_day: u16) -> Option<u16> {
-    // TODO: Complete the function body.
+    if hour_of_day > 23 {
+        None
+    } else if hour_of_day < 22 {
+            Some(5)
+        } else {
+            Some(0)
+        }
+
+    // OR
+    // fn maybe_ice_cream(hour_of_day: u16) -> Option<u16> {
+    //     match hour_of_day {
+    //         0..=21 => Some(5),
+    //         22 | 23 => Some(0),
+    //         _ => None,
+    //     }
+    // }    
 }
 
 fn main() {
@@ -20,7 +35,7 @@ mod tests {
         // Option?
         let ice_creams = maybe_ice_cream(12);
 
-        assert_eq!(ice_creams, 5); // Don't change this line.
+        assert_eq!(ice_creams, Some(5)); // Don't change this line.
     }
 
     #[test]

exercises/12_options/options2.rs

@@ -10,7 +10,10 @@ mod tests {
         let optional_target = Some(target);
 
         // TODO: Make this an if-let statement whose value is `Some`.
-        word = optional_target {
+        // word = optional_target {
+        //     assert_eq!(word, target);
+        // }
+        if let Some(word) = optional_target {
             assert_eq!(word, target);
         }
     }
@@ -29,10 +32,16 @@ mod tests {
         // 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;
+        while let Some(integer) = optional_integers.pop() {
+            if let Some(integer_value) = integer {
+                println!("integer_value (left): {}, cursor (right): {}", integer_value, cursor);
+                assert_eq!(integer_value, cursor);
+                cursor -= 1;
+            } else {
+                println!("None value, cursor: {}", cursor);
+            }
         }
+        
 
         assert_eq!(cursor, 0);
     }

exercises/12_options/options3.rs

@@ -9,7 +9,7 @@ fn main() {
 
     // TODO: Fix the compiler error by adding something to this match statement.
     match optional_point {
-        Some(p) => println!("Coordinates are {},{}", p.x, p.y),
+        Some(ref p) => println!("Coordinates are {},{}", p.x, p.y),
         _ => panic!("No match!"),
     }
 

exercises/13_error_handling/errors1.rs

@@ -4,12 +4,14 @@
 // construct to `Option` that can be used to express error conditions. Change
 // the function signature and body to return `Result<String, String>` instead
 // of `Option<String>`.
-fn generate_nametag_text(name: String) -> Option<String> {
+fn generate_nametag_text(name: String) -> Result<String, String> {
     if name.is_empty() {
         // Empty names aren't allowed
-        None
+        // None
+        Err("Empty names aren't allowed".to_string())
     } else {
-        Some(format!("Hi! My name is {name}"))
+        // Some(format!("Hi! My name is {name}"))
+        Ok(format!("Hi! My name is {name}"))
     }
 }
 

exercises/13_error_handling/errors2.rs

@@ -21,7 +21,14 @@ fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
     let cost_per_item = 5;
 
     // TODO: Handle the error case as described above.
-    let qty = item_quantity.parse::<i32>();
+    let qty = item_quantity.parse::<i32>()?;
+
+    // OR
+    // let qty_result = item_quantity.parse::<i32>();
+    // let qty = match qty_result {
+    //     Ok(number) => number,
+    //     Err(e) => return Err(e),
+    // };
 
     Ok(qty * cost_per_item + processing_fee)
 }

exercises/13_error_handling/errors3.rs

@@ -15,7 +15,7 @@ fn total_cost(item_quantity: &str) -> Result<i32, ParseIntError> {
 
 // TODO: Fix the compiler error by changing the signature and body of the
 // `main` function.
-fn main() {
+fn main() -> Result<(), ParseIntError>{
     let mut tokens = 100;
     let pretend_user_input = "8";
 
@@ -28,4 +28,6 @@ fn main() {
         tokens -= cost;
         println!("You now have {tokens} tokens.");
     }
+
+    Ok(())
 }

exercises/13_error_handling/errors4.rs

@@ -11,7 +11,13 @@ impl PositiveNonzeroInteger {
     fn new(value: i64) -> Result<Self, CreationError> {
         // TODO: This function shouldn't always return an `Ok`.
         // Read the tests below to clarify what should be returned.
-        Ok(Self(value as u64))
+        if value < 0 {
+            Err(CreationError::Negative)
+        } else if value == 0 {
+            Err(CreationError::Zero)
+        } else {
+            Ok(Self(value as u64))
+        }    
     }
 }
 

exercises/13_error_handling/errors5.rs

@@ -48,7 +48,7 @@ impl PositiveNonzeroInteger {
 
 // TODO: Add the correct return type `Result<(), Box<dyn ???>>`. What can we
 // use to describe both errors? Is there a trait which both errors implement?
-fn main() {
+fn main() -> Result<(), Box<dyn Error>>{
     let pretend_user_input = "42";
     let x: i64 = pretend_user_input.parse()?;
     println!("output={:?}", PositiveNonzeroInteger::new(x)?);

exercises/13_error_handling/errors6.rs

@@ -26,6 +26,9 @@ impl ParsePosNonzeroError {
 
     // TODO: Add another error conversion function here.
     // fn from_parse_int(???) -> Self { ??? }
+    fn from_parse_int(err: ParseIntError) -> Self {
+        Self::ParseInt(err)
+    }
 }
 
 #[derive(PartialEq, Debug)]
@@ -43,7 +46,7 @@ impl PositiveNonzeroInteger {
     fn parse(s: &str) -> Result<Self, ParsePosNonzeroError> {
         // TODO: change this to return an appropriate error instead of panicking
         // when `parse()` returns an error.
-        let x: i64 = s.parse().unwrap();
+        let x: i64 = s.parse().map_err(ParsePosNonzeroError::from_parse_int)?;
         Self::new(x).map_err(ParsePosNonzeroError::from_creation)
     }
 }

exercises/14_generics/generics1.rs

@@ -6,7 +6,7 @@ fn main() {
     // TODO: Fix the compiler error by annotating the type of the vector
     // `Vec<T>`. Choose `T` as some integer type that can be created from
     // `u8` and `i8`.
-    let mut numbers = Vec::new();
+    let mut numbers: Vec<i16> = Vec::new();
 
     // Don't change the lines below.
     let n1: u8 = 42;

exercises/14_generics/generics2.rs

@@ -1,12 +1,12 @@
 // This powerful wrapper provides the ability to store a positive integer value.
 // TODO: Rewrite it using a generic so that it supports wrapping ANY type.
-struct Wrapper {
-    value: u32,
+struct Wrapper<T> {
+    value: T,
 }
 
 // TODO: Adapt the struct's implementation to be generic over the wrapped value.
-impl Wrapper {
-    fn new(value: u32) -> Self {
+impl<T> Wrapper<T> {
+    fn new(value: T) -> Self {
         Wrapper { value }
     }
 }

exercises/15_traits/traits1.rs

@@ -6,6 +6,14 @@ trait AppendBar {
 
 impl AppendBar for String {
     // TODO: Implement `AppendBar` for the type `String`.
+    fn append_bar(self) -> Self{
+        // In this i need to put mut in front of the parameter
+        // self.push_str("Bar");
+        // self
+
+        // This way is more readable
+        self + "Bar"
+    }
 }
 
 fn main() {

exercises/15_traits/traits2.rs

@@ -4,6 +4,13 @@ trait AppendBar {
 
 // TODO: Implement the trait `AppendBar` for a vector of strings.
 // `append_bar` should push the string "Bar" into the vector.
+impl AppendBar for Vec<String> {
+    // TODO: Implement `AppendBar` for the type `String`.
+    fn append_bar(mut self) -> Self{
+        self.push("Bar".to_string());
+        self
+    }
+}
 
 fn main() {
     // You can optionally experiment here.

exercises/15_traits/traits3.rs

@@ -3,7 +3,9 @@ trait Licensed {
     // implementors like the two structs below can share that default behavior
     // without repeating the function.
     // The default license information should be the string "Default license".
-    fn licensing_info(&self) -> String;
+    fn licensing_info(&self) -> String {
+        String::from("Default license")
+    }
 }
 
 struct SomeSoftware {

exercises/15_traits/traits4.rs

@@ -11,7 +11,8 @@ impl Licensed for SomeSoftware {}
 impl Licensed for OtherSoftware {}
 
 // TODO: Fix the compiler error by only changing the signature of this function.
-fn compare_license_types(software1: ???, software2: ???) -> bool {
+fn compare_license_types(software1: impl Licensed, software2: impl Licensed) -> bool {
+    // Impl Licensed means to accept every types that implement Licensed
     software1.licensing_info() == software2.licensing_info()
 }
 

exercises/15_traits/traits5.rs

@@ -19,7 +19,7 @@ impl SomeTrait for OtherStruct {}
 impl OtherTrait for OtherStruct {}
 
 // TODO: Fix the compiler error by only changing the signature of this function.
-fn some_func(item: ???) -> bool {
+fn some_func(item: impl SomeTrait + OtherTrait) -> bool {
     item.some_function() && item.other_function()
 }