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mboulard's solution

to Bob in the Rust Track

Published at May 04 2021 · 0 comments
Instructions
Test suite
Solution

Bob is a lackadaisical teenager. In conversation, his responses are very limited.

Bob answers 'Sure.' if you ask him a question, such as "How are you?".

He answers 'Whoa, chill out!' if you YELL AT HIM (in all capitals).

He answers 'Calm down, I know what I'm doing!' if you yell a question at him.

He says 'Fine. Be that way!' if you address him without actually saying anything.

He answers 'Whatever.' to anything else.

Bob's conversational partner is a purist when it comes to written communication and always follows normal rules regarding sentence punctuation in English.

Rust Installation

Refer to the exercism help page for Rust installation and learning resources.

Writing the Code

Execute the tests with:

$ cargo test

All but the first test have been ignored. After you get the first test to pass, open the tests source file which is located in the tests directory and remove the #[ignore] flag from the next test and get the tests to pass again. Each separate test is a function with #[test] flag above it. Continue, until you pass every test.

If you wish to run all ignored tests without editing the tests source file, use:

$ cargo test -- --ignored

To run a specific test, for example some_test, you can use:

$ cargo test some_test

If the specific test is ignored use:

$ cargo test some_test -- --ignored

To learn more about Rust tests refer to the online test documentation

Make sure to read the Modules chapter if you haven't already, it will help you with organizing your files.

Further improvements

After you have solved the exercise, please consider using the additional utilities, described in the installation guide, to further refine your final solution.

To format your solution, inside the solution directory use

cargo fmt

To see, if your solution contains some common ineffective use cases, inside the solution directory use

cargo clippy --all-targets

Submitting the solution

Generally you should submit all files in which you implemented your solution (src/lib.rs in most cases). If you are using any external crates, please consider submitting the Cargo.toml file. This will make the review process faster and clearer.

Feedback, Issues, Pull Requests

The exercism/rust repository on GitHub is the home for all of the Rust exercises. If you have feedback about an exercise, or want to help implement new exercises, head over there and create an issue. Members of the rust track team are happy to help!

If you want to know more about Exercism, take a look at the contribution guide.

Source

Inspired by the 'Deaf Grandma' exercise in Chris Pine's Learn to Program tutorial. http://pine.fm/LearnToProgram/?Chapter=06

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.

bob.rs

fn process_response_case(phrase: &str, expected_response: &str) {
    assert_eq!(bob::reply(phrase), expected_response);
}

#[test]
/// stating something
fn test_stating_something() {
    process_response_case("Tom-ay-to, tom-aaaah-to.", "Whatever.");
}

#[test]
#[ignore]
/// ending with whitespace
fn test_ending_with_whitespace() {
    process_response_case("Okay if like my  spacebar  quite a bit?   ", "Sure.");
}

#[test]
#[ignore]
/// shouting numbers
fn test_shouting_numbers() {
    process_response_case("1, 2, 3 GO!", "Whoa, chill out!");
}

#[test]
#[ignore]
/// other whitespace
fn test_other_whitespace() {
    process_response_case("\r\r 	", "Fine. Be that way!");
}

#[test]
#[ignore]
/// shouting with special characters
fn test_shouting_with_special_characters() {
    process_response_case(
        "ZOMG THE %^*@#$(*^ ZOMBIES ARE COMING!!11!!1!",
        "Whoa, chill out!",
    );
}

#[test]
#[ignore]
/// talking forcefully
fn test_talking_forcefully() {
    process_response_case("Hi there!", "Whatever.");
}

#[test]
#[ignore]
/// prattling on
fn test_prattling_on() {
    process_response_case("Wait! Hang on. Are you going to be OK?", "Sure.");
}

#[test]
#[ignore]
/// forceful question
fn test_forceful_question() {
    process_response_case("WHAT'S GOING ON?", "Calm down, I know what I'm doing!");
}

#[test]
#[ignore]
/// shouting with no exclamation mark
fn test_shouting_with_no_exclamation_mark() {
    process_response_case("I HATE THE DENTIST", "Whoa, chill out!");
}

#[test]
#[ignore]
/// asking gibberish
fn test_asking_gibberish() {
    process_response_case("fffbbcbeab?", "Sure.");
}

#[test]
#[ignore]
/// question with no letters
fn test_question_with_no_letters() {
    process_response_case("4?", "Sure.");
}

#[test]
#[ignore]
/// no letters
fn test_no_letters() {
    process_response_case("1, 2, 3", "Whatever.");
}

#[test]
#[ignore]
/// statement containing question mark
fn test_statement_containing_question_mark() {
    process_response_case("Ending with ? means a question.", "Whatever.");
}

//NEW
#[test]
#[ignore]
/// multiple line question
fn test_multiple_line_question() {
    process_response_case(
        "\rDoes this cryogenic chamber make me look fat?\rNo.",
        "Whatever.",
    );
}

#[test]
#[ignore]
/// non-question ending with whitespace
fn test_nonquestion_ending_with_whitespace() {
    process_response_case(
        "This is a statement ending with whitespace      ",
        "Whatever.",
    );
}

#[test]
#[ignore]
/// shouting
fn test_shouting() {
    process_response_case("WATCH OUT!", "Whoa, chill out!");
}

#[test]
#[ignore]
/// non-letters with question
fn test_nonletters_with_question() {
    process_response_case(":) ?", "Sure.");
}

#[test]
#[ignore]
/// shouting gibberish
fn test_shouting_gibberish() {
    process_response_case("FCECDFCAAB", "Whoa, chill out!");
}

#[test]
#[ignore]
/// asking a question
fn test_asking_a_question() {
    process_response_case("Does this cryogenic chamber make me look fat?", "Sure.");
}

#[test]
#[ignore]
/// asking a numeric question
fn test_asking_a_numeric_question() {
    process_response_case("You are, what, like 15?", "Sure.");
}

#[test]
#[ignore]
/// silence
fn test_silence() {
    process_response_case("", "Fine. Be that way!");
}

#[test]
#[ignore]
/// starting with whitespace
fn test_starting_with_whitespace() {
    process_response_case("         hmmmmmmm...", "Whatever.");
}

#[test]
#[ignore]
/// using acronyms in regular speech
fn test_using_acronyms_in_regular_speech() {
    process_response_case(
        "It's OK if you don't want to go work for NASA.",
        "Whatever.",
    );
}

#[test]
#[ignore]
/// alternate silence
fn test_alternate_silence() {
    process_response_case("										", "Fine. Be that way!");
}

#[test]
#[ignore]
/// prolonged silence
fn test_prolonged_silence() {
    process_response_case("          ", "Fine. Be that way!");
}
pub fn reply(message: &str) -> &str {
    //
    decide_reply(determine_category(message))
}

enum Category {
    Question,
    Yelled,
    YelledQuestion,
    NothingSaid,
    AnythingElse,
}

fn determine_category(s: &str) -> Category {
    //
    let s = s.trim();

    if s.is_empty() {
        println!("s is empty.");
        return Category::NothingSaid;
    }

    let ends_with_question_mark =
        match s.chars().last() {
            Some(ch) => ch == '?',
            _ => false,
        };

    // There is a trait for &str further down
    let is_all_caps = s.is_all_caps();

    if ends_with_question_mark {
        return if is_all_caps {
            Category::YelledQuestion
        } else {
            Category::Question
        };
    }

    if is_all_caps {
        return Category::Yelled;
    }

    Category::AnythingElse
}

fn decide_reply(cat: Category) -> &'static str {
    // This is where the Artificial Intelligence team
    // can change Bob's behaviors.
    match cat {
        Category::Question => "Sure.",
        Category::Yelled => "Whoa, chill out!",
        Category::YelledQuestion => "Calm down, I know what I'm doing!",
        Category::NothingSaid => "Fine. Be that way!",
        Category::AnythingElse => "Whatever.",
    }
}

// I am reading chap. 10 of the Rust "Book", so here's a trait.
trait CaseCheck {
    fn is_all_caps(&self) -> bool;
}

impl CaseCheck for &str {
    fn is_all_caps(&self) -> bool {
        //
        let mut iter = self.chars();

        // The goal of this spaghetti is to test characters only once.
        while let Some(ch) = iter.next() {
            if ch.is_uppercase() {
                while let Some(ch) = iter.next() {
                    if ch.is_lowercase() {
                        return false;
                    }
                }
                return true;
            }
        }
        false
    }
}

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