added more questions and answers

code_example_study/examples/studying_of_lucianos_advent_code_ver2.rs

@@ -248,4 +248,213 @@ fn main() {
 //    - Internally, `try_into()` calls the `try_from` method implemented for the target type `T`, passing `self` (the string slice) as the argument.
 //    - The `try_from` method performs the conversion and returns a `Result<T, Error>`, which is then returned by `try_into()`.
 //
-// By implementing the `TryFrom` trait for a type, you enable the use of the `try_into()` method for converting values of other types into the implementing type. This provides a convenient and idiomatic way to perform type conversions that may fail, using the `Result` type to handle success or failure.
+// By implementing the `TryFrom` trait for a type, you enable the use of the `try_into()` method for converting values of other types into the implementing type. This provides a convenient and idiomatic way to perform type conversions that may fail, using the `Result` type to handle success or failure.
+
+
+
+
+// S
+//
+// I have the following Rust code.
+//
+// """
+//
+// use std::str::FromStr; enum Instr { Mask(String), Mem(u64, u64), } impl FromStr for Instr { //implementing FromStr trait, will make the parse() method available type Err = String; fn from_str(s: &str) -> Result<Self, Self::Err> { if s.starts_with("mask") { Ok(Instr::Mask(s[7..].to_string())) } else if s.starts_with("mem") { let addr_value = &mut s[4..].split("] = "); let addr: u64 = addr_value.next().unwrap().parse().unwrap(); let value: u64 = addr_value.next().unwrap().parse().unwrap(); Ok(Instr::Mem(addr, value)) } else { Err(format!("Invalid line found: {s}")) } } } fn main() { //problem : //y2020 - Day 14: Docking Data // mask = 000000000000000000000000000000X1001X // mem[42] = 100 // mask = 00000000000000000000000000000000X0XX // mem[26] = 1 // ... let mask: Instr = "mask = 000000000000000X1001X".parse().unwrap(); assert_eq!(mask, Instr::Mask("000000000000000X1001X".to_string())); let mem: Instr = "mem[42] = 100".parse().unwrap(); assert_eq!(mem, Instr::Mem(42, 100)); }
+//
+// """
+//
+// It fails with the following error message :
+//
+// """
+//
+// error[E0369]: binary operation == cannot be applied to type Instr
+//
+// --> code_example_study/examples/studying_of_lucianos_advent_code_ver1.rs:45:5
+//
+// |
+//
+// 45 | assert_eq!(mask, Instr::Mask("000000000000000X1001X".to_string()));
+//
+// | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+//
+// | |
+//
+// | Instr
+//
+// | Instr
+//
+// |
+//
+// note: an implementation of PartialEq might be missing for Instr
+//
+// --> code_example_study/examples/studying_of_lucianos_advent_code_ver1.rs:14:1
+//
+// |
+//
+// 14 | enum Instr {
+//
+// | ^^^^^^^^^^ must implement PartialEq
+//
+// = note: this error originates in the macro assert_eq (in Nightly builds, run with -Z macro-backtrace for more info)
+//
+// help: consider annotating Instr with #[derive(PartialEq)]
+//
+// |
+//
+// 14 + #[derive(PartialEq)]
+//
+// 15 | enum Instr {
+//
+// |
+//
+// error[E0277]: Instr doesn't implement Debug
+//
+// --> code_example_study/examples/studying_of_lucianos_advent_code_ver1.rs:45:5
+//
+// |
+//
+// 45 | assert_eq!(mask, Instr::Mask("000000000000000X1001X".to_string()));
+//
+// | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Instr cannot be formatted using {:?}
+//
+// |
+//
+// = help: the trait Debug is not implemented for Instr
+//
+// = note: add #[derive(Debug)] to Instr or manually impl Debug for Instr
+//
+// = note: this error originates in the macro assert_eq (in Nightly builds, run with -Z macro-backtrace for more info)
+//
+// help: consider annotating Instr with #[derive(Debug)]
+//
+// |
+//
+// 14 + #[derive(Debug)]
+//
+// 15 | enum Instr {
+//
+// |
+//
+// error[E0369]: binary operation == cannot be applied to type Instr
+//
+// --> code_example_study/examples/studying_of_lucianos_advent_code_ver1.rs:48:5
+//
+// |
+//
+// 48 | assert_eq!(mem, Instr::Mem(42, 100));
+//
+// | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+//
+// | |
+//
+// | Instr
+//
+// | Instr
+//
+// |
+//
+// note: an implementation of PartialEq might be missing for Instr
+//
+// --> code_example_study/examples/studying_of_lucianos_advent_code_ver1.rs:14:1
+//
+// |
+//
+// 14 | enum Instr {
+//
+// | ^^^^^^^^^^ must implement PartialEq
+//
+// = note: this error originates in the macro assert_eq (in Nightly builds, run with -Z macro-backtrace for more info)
+//
+// help: consider annotating Instr with #[derive(PartialEq)]
+//
+// |
+//
+// 14 + #[derive(PartialEq)]
+//
+// 15 | enum Instr {
+//
+// |
+//
+// error[E0277]: Instr doesn't implement Debug
+//
+// --> code_example_study/examples/studying_of_lucianos_advent_code_ver1.rs:48:5
+//
+// |
+//
+// 48 | assert_eq!(mem, Instr::Mem(42, 100));
+//
+// | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Instr cannot be formatted using {:?}
+//
+// |
+//
+// = help: the trait Debug is not implemented for Instr
+//
+// = note: add #[derive(Debug)] to Instr or manually impl Debug for Instr
+//
+// = note: this error originates in the macro assert_eq (in Nightly builds, run with -Z macro-backtrace for more info)
+//
+// help: consider annotating Instr with #[derive(Debug)]
+//
+// |
+//
+// 14 + #[derive(Debug)]
+//
+// 15 | enum Instr {
+//
+// |
+//
+// """
+//
+// What would be your suggestions?
+
+// The error messages suggest that the `Instr` enum is missing implementations for the `PartialEq` and `Debug` traits, which are required for using `assert_eq!` and printing the enum values with `{:?}` respectively.
+//
+// To fix this, you can derive the `PartialEq` and `Debug` traits for the `Instr` enum by adding the `#[derive(PartialEq, Debug)]` attribute above the enum definition. Here's the updated code:
+//
+// ```rust
+// use std::str::FromStr;
+//
+// #[derive(PartialEq, Debug)]
+// enum Instr {
+//     Mask(String),
+//     Mem(u64, u64),
+// }
+//
+// impl FromStr for Instr {
+//     // implementing FromStr trait, will make the parse() method available
+//     type Err = String;
+//
+//     fn from_str(s: &str) -> Result<Self, Self::Err> {
+//         if s.starts_with("mask") {
+//             Ok(Instr::Mask(s[7..].to_string()))
+//         } else if s.starts_with("mem") {
+//             let addr_value = &mut s[4..].split("] = ");
+//             let addr: u64 = addr_value.next().unwrap().parse().unwrap();
+//             let value: u64 = addr_value.next().unwrap().parse().unwrap();
+//             Ok(Instr::Mem(addr, value))
+//         } else {
+//             Err(format!("Invalid line found: {s}"))
+//         }
+//     }
+// }
+//
+// fn main() {
+//     // problem:
+//     // y2020 - Day 14: Docking Data
+//     // mask = 000000000000000000000000000000X1001X
+//     // mem[42] = 100
+//     // mask = 00000000000000000000000000000000X0XX
+//     // mem[26] = 1
+//     // ...
+//
+//     let mask: Instr = "mask = 000000000000000X1001X".parse().unwrap();
+//     assert_eq!(mask, Instr::Mask("000000000000000X1001X".to_string()));
+//
+//     let mem: Instr = "mem[42] = 100".parse().unwrap();
+//     assert_eq!(mem, Instr::Mem(42, 100));
+// }
+// ```
+//
+// By adding `#[derive(PartialEq, Debug)]` above the `Instr` enum definition, the Rust compiler will automatically generate the necessary implementations for the `PartialEq` and `Debug` traits.
+//
+// With these changes, the code should compile without any errors, and the `assert_eq!` statements should pass successfully.

my_qustions_and_ai_answers/ the concepts of free and malloc in c help Rust programming

@@ -0,0 +1,19 @@
+The concepts of `free()` and `malloc()` from C are related to manual memory management, where the programmer is responsible for allocating and deallocating memory. However, Rust takes a different approach to memory management.
+
+In Rust, memory management is handled through ownership, borrowing, and lifetimes. Rust enforces strict rules at compile-time to ensure memory safety and prevent common issues like null or dangling pointer dereferences, buffer overflows, and memory leaks.
+
+Here are some key differences and concepts in Rust:
+
+1. Ownership: In Rust, every value has an owner, and there can only be one owner at a time. When the owner goes out of scope, the value is automatically deallocated. This eliminates the need for manual memory management using functions like `malloc()` and `free()`.
+
+2. Borrowing: Rust allows borrowing of values through references. You can have multiple immutable references or a single mutable reference to a value at a time. This helps prevent data races and ensures safe concurrent access to data.
+
+3. Lifetimes: Rust uses lifetimes to ensure that references are valid and do not outlive the data they refer to. The compiler tracks the lifetimes of references and ensures that they are used correctly, preventing issues like dangling references.
+
+4. Smart Pointers: Rust provides smart pointers, such as `Box<T>`, `Rc<T>`, and `Arc<T>`, which are used for heap allocation and automatic memory management. These smart pointers handle the allocation and deallocation of memory safely and efficiently.
+
+5. RAII (Resource Acquisition Is Initialization): Rust follows the RAII principle, where resources (such as memory) are acquired during the initialization of an object and automatically released when the object goes out of scope. This helps in writing safe and leak-free code.
+
+While the concepts of `free()` and `malloc()` are not directly applicable in Rust, understanding memory management and how Rust ensures memory safety through ownership, borrowing, and lifetimes is crucial for effective Rust programming.
+
+Rust's approach to memory management aims to provide the benefits of manual memory management, such as fine-grained control and performance, while also ensuring memory safety and preventing common programming errors at compile-time.