Merge branch 'mr/486-create-lab-for-module-common-library-types' into 'master'

Resolve "Create Lab for Module: Common Library Types"

Closes #486

See merge request feng/training/material!562

Author: Dana Binkley

courses/rust_essentials/110_common_library_types/88-common_library_types.lab.rst

@@ -1,67 +1,17 @@
-===================
-Exercise: Counter
-===================
+=====
+Lab
+=====
 
--------------------
-Counter Problem
--------------------
+------------------
+Lab Instructions
+------------------
 
-In this exercise you will take a very simple data structure and make it
-generic. It uses a
-:url:`std::collections::HashMap <https://doc.rust-lang.org/stable/std/collections/struct.HashMap.html>`
-to keep track of which values have been seen and how many times each one
-has appeared.
+- Solve for compilation errors
 
-The initial version of :rust:`Counter` is hard coded to only work for
-:rust:`u32` values. Make the struct and its methods generic over the type of
-value being tracked, that way :rust:`Counter` can track any type of value.
+- Follow the hints!
 
-If you finish early, try using the
-:url:`entry <https://doc.rust-lang.org/stable/std/collections/struct.HashMap.html#method.entry>`
-method to halve the number of hash lookups required to implement the
-:rust:`count` method.
+- Success is
 
-::
-
-   use std::collections::HashMap;
-
-   /// Counter counts the number of times each value of type T has been seen.
-   struct Counter {
-       values: HashMap<u32, u64>,
-   }
-
-   impl Counter {
-       /// Create a new Counter.
-       fn new() -> Self {
-           Counter {
-               values: HashMap::new(),
-           }
-       }
-
-       /// Count an occurrence of the given value.
-       fn count(&mut self, value: u32) {
-           if self.values.contains_key(&value) {
-               *self.values.get_mut(&value).unwrap() += 1;
-           } else {
-               self.values.insert(value, 1);
-           }
-       }
-
-       /// Return the number of times the given value has been seen.
-       fn times_seen(&self, value: u32) -> u64 {
-           self.values.get(&value).copied().unwrap_or_default()
-       }
-   }
-
-------------------------
-Counter - Main Program
-------------------------
-
-.. container:: source_include 110_common_library_types/src/110_common_library_types.rs :start-after://ANCHOR-main :code:rust :number-lines:1
-
--------------------
-Counter Solution
--------------------
-
-.. container:: source_include 110_common_library_types/src/110_common_library_types.rs :start-after://ANCHOR-solution :end-before://ANCHOR-main :code:rust :number-lines:1
+    - Code that compiles
 
+    - ...and that follows any behavior indicated within the hints!

courses/rust_essentials/110_common_library_types/lab/answer/Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-name = "lab"
+name = "answer"
 version = "1.0.0"
 edition = "2024"
 

courses/rust_essentials/110_common_library_types/lab/answer/src/main.rs

@@ -1,3 +1,52 @@
+//! Lab (answer)
+//! Common Library Types
+//!
+#[allow(dead_code)]
+#[allow(unused_variables)]
 fn main() {
-    println!("TBD");
+    
+    // TASK 1 - 'Option' Type Handling
+    // Hint: 'Option<T>' must be explicitly handled
+    let maybe_number = Some(42);
+    let result = match maybe_number {
+        Some(v) => v + 10,
+        None => 0,
+    };    
+    println!("TASK1 => result: {}", result);
+
+    // TASK 2 - 'Result' Variants
+    // Hint: 'Result' uses 'Ok(T)' and 'Err(E)'
+    fn check_positive(num: i32) -> Result<i32, String> {
+        if num > 0 { 
+            Ok(num) // Replaced Some with Ok
+        } else { 
+            Err(String::from("Not a positive number")) // Replaced None with Err
+        }
+    }
+    println!("TASK2 => check: {:?}", check_positive(-5));
+
+    // TASK 3 - 'String' vs '&str'
+    // Hint: '&str' is a fixed view, an owned and growable 'String' is needed to append text
+    let mut greeting = String::from("Hello"); // Converted to an owned 'String'
+    greeting.push_str(" world");
+    println!("TASK3 => greeting: {}", greeting);
+
+    // TASK 4 - Modifying Strings ('push' vs 'push_str')
+    // Hint: Which 'String' method appends a slice instead of a single 'char'?
+    let mut text = String::from("Rust");
+    text.push_str(" is great"); // Changed 'push' to 'push_str'
+    println!("TASK4 => text: {}", text);
+
+    // TASK 5 - Vector Creation Macro
+    // Hint: How is a macro invoked differently than a function?
+    let numbers = vec![1, 2, 3]; // Added '!' to properly invoke the macro
+    println!("TASK5 => numbers length: {}", numbers.len());
+
+    // TASK 6 - Representing Absence
+    // Hint: Rust does not have null pointers, absence is represented by the appropriate 'Option' variant
+    fn get_user(id: u32) -> Option<String> {
+        None // Replaced null with 'None'
+    }
+    println!("TASK6 => get_user(1): {:?}", get_user(1));
+
 }

courses/rust_essentials/110_common_library_types/lab/prompt/Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-name = "lab"
+name = "prompt"
 version = "1.0.0"
 edition = "2024"
 

courses/rust_essentials/110_common_library_types/lab/prompt/src/main.rs

@@ -1,3 +1,46 @@
+//! Lab (prompt)
+//! Common Library Types
+//!
+//! Fix all the compile errors below by following the hints provided 
+//! 
+#[allow(dead_code)]
+#[allow(unused_variables)]
 fn main() {
-    println!("TBD");
+
+    // TASK 1 - 'Option' Type Handling
+    // Hint: 'Option<T>' must be explicitly handled
+    let maybe_number = Some(42);
+    let result = maybe_number + 10;
+
+    // TASK 2 - 'Result' Variants
+    // Hint: 'Result' uses 'Ok(T)' and 'Err(E)'
+    fn check_positive(num: i32) -> Result<i32, String> {
+        if num > 0 { 
+            Some(num) 
+        } else { 
+            None 
+        }
+    }
+
+    // TASK 3 - 'String' vs '&str'
+    // Hint: '&str' is a fixed view, an owned and growable 'String' is needed to append text
+    let mut greeting = "Hello";
+    greeting.push_str(" world");
+
+    // TASK 4 - Modifying Strings ('push' vs 'push_str')
+    // Hint: Which 'String' method appends a slice instead of a single 'char'?
+    let mut text = String::from("Rust");
+    text.push(" is great");
+
+    // TASK 5 - Vector Creation Macro
+    // Hint: How is a macro invoked differently than a function?
+    let numbers = vec[1, 2, 3];
+
+    // TASK 6 - Representing Absence
+    // Hint: Rust does not have null pointers, absence is represented by the appropriate 'Option' variant
+    fn get_user(id: u32) -> Option<String> {
+        null
+    }
+        println!("TASK6 => get_user(1): {:?}", get_user(1));
+
 }