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0ndorio's solution

to Bob in the C++ Track

Published at Jul 13 2018 · 1 comment
Instructions
Test suite
Solution

Note:

This solution was written on an old version of Exercism. The tests below might not correspond to the solution code, and the exercise may have changed since this code was written.

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

Bob answers 'Sure.' if you ask him a question.

He answers 'Whoa, chill out!' if you yell at him.

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

He answers 'Whatever.' to anything else.

Getting Started

Make sure you have read the C++ page on exercism.io. This covers the basic information on setting up the development environment expected by the exercises.

Passing the Tests

Get the first test compiling, linking and passing by following the three rules of test-driven development. Create just enough structure by declaring namespaces, functions, classes, etc., to satisfy any compiler errors and get the test to fail. Then write just enough code to get the test to pass. Once you've done that, uncomment the next test by moving the following line past the next test.

#if defined(EXERCISM_RUN_ALL_TESTS)

This may result in compile errors as new constructs may be invoked that you haven't yet declared or defined. Again, fix the compile errors minimally to get a failing test, then change the code minimally to pass the test, refactor your implementation for readability and expressiveness and then go on to the next test.

Try to use standard C++11 facilities in preference to writing your own low-level algorithms or facilities by hand. CppReference is a wiki reference to the C++ language and standard library. If you are new to C++, but have programmed in C, beware of C traps and pitfalls.

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_test.cpp

#include "bob.h"
#define BOOST_TEST_MAIN
#include <boost/test/unit_test.hpp>

BOOST_AUTO_TEST_CASE(stating_something)
{
    BOOST_REQUIRE_EQUAL("Whatever.", bob::hey("Tom-ay-to, tom-aaaah-to."));
}

#if defined(EXERCISM_RUN_ALL_TESTS)
BOOST_AUTO_TEST_CASE(shouting)
{
    BOOST_REQUIRE_EQUAL("Whoa, chill out!", bob::hey("WATCH OUT!"));
}

BOOST_AUTO_TEST_CASE(asking_a_question)
{
    BOOST_REQUIRE_EQUAL("Sure.", bob::hey("Does this cryogenic chamber make me look fat?"));
}

BOOST_AUTO_TEST_CASE(talking_forcefully)
{
    BOOST_REQUIRE_EQUAL("Whatever.", bob::hey("Let's go make out behind the gym!"));
}

BOOST_AUTO_TEST_CASE(using_acronyms_in_regular_speech)
{
    BOOST_REQUIRE_EQUAL("Whatever.", bob::hey("It's OK if you don't want to go to the DMV."));
}

BOOST_AUTO_TEST_CASE(forceful_questions)
{
    BOOST_REQUIRE_EQUAL("Whoa, chill out!", bob::hey("WHAT THE HELL WERE YOU THINKING?"));
}

BOOST_AUTO_TEST_CASE(shouting_numbers)
{
    BOOST_REQUIRE_EQUAL("Whoa, chill out!", bob::hey("1, 2, 3 GO!"));
}

BOOST_AUTO_TEST_CASE(only_numbers)
{
    BOOST_REQUIRE_EQUAL("Whatever.", bob::hey("1, 2, 3"));
}

BOOST_AUTO_TEST_CASE(question_with_only_numbers)
{
    BOOST_REQUIRE_EQUAL("Sure.", bob::hey("4?"));
}

BOOST_AUTO_TEST_CASE(shouting_with_special_characters)
{
    BOOST_REQUIRE_EQUAL("Whoa, chill out!", bob::hey("ZOMG THE %^*@#$(*^ ZOMBIES ARE COMING!!11!!1!"));
}

BOOST_AUTO_TEST_CASE(shouting_with_no_exclamation_mark)
{
    BOOST_REQUIRE_EQUAL("Whoa, chill out!", bob::hey("I HATE YOU"));
}

BOOST_AUTO_TEST_CASE(statement_containing_question_mark)
{
    BOOST_REQUIRE_EQUAL("Whatever.", bob::hey("Ending with a ? means a question."));
}

BOOST_AUTO_TEST_CASE(prattling_on)
{
    BOOST_REQUIRE_EQUAL("Sure.", bob::hey("Wait! Hang on.  Are you going to be OK?"));
}

BOOST_AUTO_TEST_CASE(question_with_trailing_whitespace)
{
    BOOST_REQUIRE_EQUAL("Sure.", bob::hey("Are you ok? "));
}

BOOST_AUTO_TEST_CASE(silence)
{
    BOOST_REQUIRE_EQUAL("Fine. Be that way!", bob::hey(""));
}

BOOST_AUTO_TEST_CASE(prolonged_silence)
{
    BOOST_REQUIRE_EQUAL("Fine. Be that way!", bob::hey("   "));
}

BOOST_AUTO_TEST_CASE(not_all_silence)                                                                         
{                                                                                                             
	BOOST_REQUIRE_EQUAL("Whatever.", bob::hey(" A bit of silence can be nice.  "));                           
}
#endif
#include "bob.h"

#include <algorithm>
#include <boost/algorithm/string.hpp>

#if FALSE // work around for exercisms one file rule
    #ifndef BOB_H
    #define BOB_H

    #include <string>

    class bob
    {
    public:

        static std::string hey(const std::string &request);

    private:

        static bool isQuestion(const std::string &request);
        static bool isYelling(const std::string &request);
        static bool hasNoContent(const std::string &request);
    };

    #endif /* BOB_H */
#endif

std::string bob::hey(const std::string &request)
{
    std::string response = "Whatever.";

    if (hasNoContent(request)) {
        response = "Fine. Be that way!";
    } else if (isYelling(request)) {
        response = "Whoa, chill out!";
    } else if (isQuestion(request)) {
        response = "Sure.";
    }

    return response;
}

bool bob::isQuestion(const std::string &request)
{
    auto trimmedRequest = boost::algorithm::trim_copy(request);
    return trimmedRequest.back() == '?';
}

bool bob::isYelling(const std::string &request)
{
    auto containsLetters = [](const char chr) {
        return std::isalpha(chr);
    };

    auto containsNotYelledLetters = [](const char chr) {
        return std::islower(chr) && std::isalpha(chr);
    };

    auto hasLetters = std::count_if(request.begin(), request.end(), containsLetters);
    auto isYelled = std::none_of(request.begin(), request.end(), containsNotYelledLetters);

    return hasLetters && isYelled;
}

bool bob::hasNoContent(const std::string &request)
{
    auto hasNoRealContent = std::all_of(request.begin(), request.end(),
        [](const char chr) {
            return std::isspace(chr) || std::ispunct(chr);
        }
    );

    return hasNoRealContent;
}

Community comments

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Avatar of NobbZ

Do you really need boost-lib for this simple task or can you imagine a way to solve this only using std-stuff?

What can you learn from this solution?

A huge amount can be learned from reading other people’s code. This is why we wanted to give exercism users the option of making their solutions public.

Here are some questions to help you reflect on this solution and learn the most from it.

  • What compromises have been made?
  • Are there new concepts here that you could read more about to improve your understanding?