diff options
| -rw-r--r-- | exercises/quizzes/quiz2.rs | 45 | ||||
| -rw-r--r-- | solutions/quizzes/quiz2.rs | 108 |
2 files changed, 130 insertions, 23 deletions
diff --git a/exercises/quizzes/quiz2.rs b/exercises/quizzes/quiz2.rs index e01e3f1..fd6bc77 100644 --- a/exercises/quizzes/quiz2.rs +++ b/exercises/quizzes/quiz2.rs @@ -11,10 +11,11 @@ // - Uppercase the string // - Trim the string // - Append "bar" to the string a specified amount of times +// // The exact form of this will be: -// - The input is going to be a Vector of a 2-length tuple, +// - The input is going to be a vector of a 2-length tuple, // the first element is the string, the second one is the command. -// - The output element is going to be a Vector of strings. +// - The output element is going to be a vector of strings. enum Command { Uppercase, @@ -25,15 +26,8 @@ enum Command { mod my_module { use super::Command; - // TODO: Complete the function signature! - pub fn transformer(input: ???) -> ??? { - // TODO: Complete the output declaration! - let mut output: ??? = vec![]; - for (string, command) in input.iter() { - // TODO: Complete the function body. You can do it! - } - output - } + // TODO: Complete the function. + // pub fn transformer(input: ???) -> ??? { ??? } } fn main() { @@ -43,20 +37,27 @@ fn main() { #[cfg(test)] mod tests { // TODO: What do we need to import to have `transformer` in scope? - use ???; + // use ???; use super::Command; #[test] fn it_works() { - let output = transformer(vec![ - ("hello".into(), Command::Uppercase), - (" all roads lead to rome! ".into(), Command::Trim), - ("foo".into(), Command::Append(1)), - ("bar".into(), Command::Append(5)), - ]); - assert_eq!(output[0], "HELLO"); - assert_eq!(output[1], "all roads lead to rome!"); - assert_eq!(output[2], "foobar"); - assert_eq!(output[3], "barbarbarbarbarbar"); + let input = vec![ + ("hello".to_string(), Command::Uppercase), + (" all roads lead to rome! ".to_string(), Command::Trim), + ("foo".to_string(), Command::Append(1)), + ("bar".to_string(), Command::Append(5)), + ]; + let output = transformer(input); + + assert_eq!( + output, + [ + "HELLO", + "all roads lead to rome!", + "foobar", + "barbarbarbarbarbar", + ] + ); } } diff --git a/solutions/quizzes/quiz2.rs b/solutions/quizzes/quiz2.rs index 4e18198..0d2a513 100644 --- a/solutions/quizzes/quiz2.rs +++ b/solutions/quizzes/quiz2.rs @@ -1 +1,107 @@ -// Solutions will be available before the stable release. Thank you for testing the beta version 🥰 +// This is a quiz for the following sections: +// - Strings +// - Vecs +// - Move semantics +// - Modules +// - Enums +// +// Let's build a little machine in the form of a function. As input, we're going +// to give a list of strings and commands. These commands determine what action +// is going to be applied to the string. It can either be: +// - Uppercase the string +// - Trim the string +// - Append "bar" to the string a specified amount of times +// +// The exact form of this will be: +// - The input is going to be a vector of a 2-length tuple, +// the first element is the string, the second one is the command. +// - The output element is going to be a vector of strings. + +enum Command { + Uppercase, + Trim, + Append(usize), +} + +mod my_module { + use super::Command; + + // The solution with a loop. Check out `transformer_iter` for a version + // with iterators. + pub fn transformer(input: Vec<(String, Command)>) -> Vec<String> { + let mut output = Vec::new(); + + for (mut string, command) in input { + // Create the new string. + let new_string = match command { + Command::Uppercase => string.to_uppercase(), + Command::Trim => string.trim().to_string(), + Command::Append(n) => { + for _ in 0..n { + string += "bar"; + } + string + } + }; + + // Push the new string to the output vector. + output.push(new_string); + } + + output + } + + // Equivalent to `transform` but uses an iterator instead of a loop for + // comparison. Don't worry, we will practice iterators later ;) + pub fn transformer_iter(input: Vec<(String, Command)>) -> Vec<String> { + input + .into_iter() + .map(|(mut string, command)| match command { + Command::Uppercase => string.to_uppercase(), + Command::Trim => string.trim().to_string(), + Command::Append(n) => { + for _ in 0..n { + string += "bar"; + } + string + } + }) + .collect() + } +} + +fn main() { + // You can optionally experiment here. +} + +#[cfg(test)] +mod tests { + // Import `transformer`. + use super::my_module::transformer; + + use super::my_module::transformer_iter; + use super::Command; + + #[test] + fn it_works() { + for transformer in [transformer, transformer_iter] { + let input = vec![ + ("hello".to_string(), Command::Uppercase), + (" all roads lead to rome! ".to_string(), Command::Trim), + ("foo".to_string(), Command::Append(1)), + ("bar".to_string(), Command::Append(5)), + ]; + let output = transformer(input); + + assert_eq!( + output, + [ + "HELLO", + "all roads lead to rome!", + "foobar", + "barbarbarbarbarbar", + ] + ); + } + } +} |