src/numbers/ordinalize/mod.rs

/// Orginalizes a `&str`
///
/// ```
///     use inflector::numbers::ordinalize::ordinalize;
///     let mock_string: &str = "a";
///     let expected_string: String = "a".to_owned();
///     let asserted_string: String = ordinalize(mock_string);
///     assert!(asserted_string == expected_string);
///
/// ```
/// ```
///     use inflector::numbers::ordinalize::ordinalize;
///     let mock_string: &str = "0.1";
///     let expected_string: String = "0.1".to_owned();
///     let asserted_string: String = ordinalize(mock_string);
///     assert!(asserted_string == expected_string);
///
/// ```
/// ```
///     use inflector::numbers::ordinalize::ordinalize;
///     let mock_string: &str = "-1";
///     let expected_string: String = "-1st".to_owned();
///     let asserted_string: String = ordinalize(mock_string);
///     assert!(asserted_string == expected_string);
///
/// ```
/// ```
///     use inflector::numbers::ordinalize::ordinalize;
///     let mock_string: &str = "0";
///     let expected_string: String = "0th".to_owned();
///     let asserted_string: String = ordinalize(mock_string);
///     assert!(asserted_string == expected_string);
///
/// ```
/// ```
///     use inflector::numbers::ordinalize::ordinalize;
///     let mock_string: &str = "1";
///     let expected_string: String = "1st".to_owned();
///     let asserted_string: String = ordinalize(mock_string);
///     assert!(asserted_string == expected_string);
///
/// ```
/// ```
///     use inflector::numbers::ordinalize::ordinalize;
///     let mock_string: &str = "2";
///     let expected_string: String = "2nd".to_owned();
///     let asserted_string: String = ordinalize(mock_string);
///     assert!(asserted_string == expected_string);
///
/// ```
/// ```
///     use inflector::numbers::ordinalize::ordinalize;
///     let mock_string: &str = "3";
///     let expected_string: String = "3rd".to_owned();
///     let asserted_string: String = ordinalize(mock_string);
///     assert!(asserted_string == expected_string);
///
/// ```
/// ```
///     use inflector::numbers::ordinalize::ordinalize;
///     let mock_string: &str = "9";
///     let expected_string: String = "9th".to_owned();
///     let asserted_string: String = ordinalize(mock_string);
///     assert!(asserted_string == expected_string);
///
/// ```
/// ```
///     use inflector::numbers::ordinalize::ordinalize;
///     let mock_string: &str = "12";
///     let expected_string: String = "12th".to_owned();
///     let asserted_string: String = ordinalize(mock_string);
///     assert!(asserted_string == expected_string);
///
/// ```
/// ```
///     use inflector::numbers::ordinalize::ordinalize;
///     let mock_string: &str = "12000";
///     let expected_string: String = "12000th".to_owned();
///     let asserted_string: String = ordinalize(mock_string);
///     assert!(asserted_string == expected_string);
///
/// ```
/// ```
///     use inflector::numbers::ordinalize::ordinalize;
///     let mock_string: &str = "12001";
///     let expected_string: String = "12001st".to_owned();
///     let asserted_string: String = ordinalize(mock_string);
///     assert!(asserted_string == expected_string);
///
/// ```
/// ```
///     use inflector::numbers::ordinalize::ordinalize;
///     let mock_string: &str = "12002";
///     let expected_string: String = "12002nd".to_owned();
///     let asserted_string: String = ordinalize(mock_string);
///     assert!(asserted_string == expected_string);
///
/// ```
/// ```
///     use inflector::numbers::ordinalize::ordinalize;
///     let mock_string: &str = "12003";
///     let expected_string: String = "12003rd".to_owned();
///     let asserted_string: String = ordinalize(mock_string);
///     assert!(asserted_string == expected_string);
///
/// ```
/// ```
///     use inflector::numbers::ordinalize::ordinalize;
///     let mock_string: &str = "12004";
///     let expected_string: String = "12004th".to_owned();
///     let asserted_string: String = ordinalize(mock_string);
///     assert!(asserted_string == expected_string);
///
/// ```
pub fn ordinalize(non_ordinalized_string: &str) -> String {
    let chars: Vec<char> = non_ordinalized_string.clone().chars().collect();
    let last_number: char = chars[chars.len() - 1];
    if is_ordinalizable(last_number) {
        return non_ordinalized_string.to_owned();
    }
    if chars.len() > 1 {
        if second_last_number_is_one(chars) {
            return format!("{}{}", non_ordinalized_string, "th");
        } else if string_contains_decimal(non_ordinalized_string.to_owned()) {
            return non_ordinalized_string.to_owned();
        }
    }
    match last_number {
        '1' => format!("{}{}", non_ordinalized_string, "st"),
        '2' => format!("{}{}", non_ordinalized_string, "nd"),
        '3' => format!("{}{}", non_ordinalized_string, "rd"),
        _ => format!("{}{}", non_ordinalized_string, "th"),
    }
}

fn is_ordinalizable(last_number: char) -> bool {
    !last_number.is_numeric()
}

fn second_last_number_is_one(chars: Vec<char>) -> bool {
    let second_last_number: char = chars[chars.len() - 2];
    second_last_number == '1'
}

fn string_contains_decimal(non_ordinalized_string: String) -> bool {
    non_ordinalized_string.contains('.')
}