etl: initial commit

cpp/etl/CMakeLists.txt

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+# Get the exercise name from the current directory
+get_filename_component(exercise ${CMAKE_CURRENT_SOURCE_DIR} NAME)
+
+# Basic CMake project
+cmake_minimum_required(VERSION 2.8.11)
+
+# Name the project after the exercise
+project(${exercise} CXX)
+
+# Locate Boost libraries: unit_test_framework, date_time and regex
+set(Boost_USE_STATIC_LIBS ON)
+set(Boost_USE_MULTITHREADED ON)
+set(Boost_USE_STATIC_RUNTIME OFF)
+find_package(Boost 1.55 REQUIRED COMPONENTS unit_test_framework date_time regex)
+
+# Enable C++11 features on gcc/clang
+if("${CMAKE_CXX_COMPILER_ID}" MATCHES "(GNU|Clang)")
+    set(CMAKE_CXX_FLAGS "-std=c++11")
+endif()
+
+# Configure to run all the tests?
+if(${EXERCISM_RUN_ALL_TESTS})
+    add_definitions(-DEXERCISM_RUN_ALL_TESTS)
+endif()
+
+# Get a source filename from the exercise name by replacing -'s with _'s
+string(REPLACE "-" "_" file ${exercise})
+
+# Implementation could be only a header
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${file}.cpp)
+    set(exercise_cpp ${file}.cpp)
+else()
+    set(exercise_cpp "")
+endif()
+
+# Build executable from sources and headers
+add_executable(${exercise} ${file}_test.cpp ${exercise_cpp} ${file}.h)
+
+# We need boost includes
+target_include_directories(${exercise} PRIVATE ${Boost_INCLUDE_DIRS})
+
+# We need boost libraries
+target_link_libraries(${exercise} ${Boost_LIBRARIES})
+
+# Tell MSVC not to warn us about unchecked iterators in debug builds
+if(${MSVC})
+    set_target_properties(${exercise} PROPERTIES
+        COMPILE_DEFINITIONS_DEBUG _SCL_SECURE_NO_WARNINGS)
+endif()
+
+# Run the tests on every build
+add_custom_command(TARGET ${exercise} POST_BUILD COMMAND ${exercise})

cpp/etl/README.md

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+# Etl
+
+We are going to do the `Transform` step of an Extract-Transform-Load.
+
+### ETL
+Extract-Transform-Load (ETL) is a fancy way of saying, "We have some crufty, legacy data over in this system, and now we need it in this shiny new system over here, so
+we're going to migrate this."
+
+(Typically, this is followed by, "We're only going to need to run this
+once." That's then typically followed by much forehead slapping and
+moaning about how stupid we could possibly be.)
+
+### The goal
+We're going to extract some scrabble scores from a legacy system.
+
+The old system stored a list of letters per score:
+
+- 1 point: "A", "E", "I", "O", "U", "L", "N", "R", "S", "T",
+- 2 points: "D", "G",
+- 3 points: "B", "C", "M", "P",
+- 4 points: "F", "H", "V", "W", "Y",
+- 5 points: "K",
+- 8 points: "J", "X",
+- 10 points: "Q", "Z",
+
+The shiny new scrabble system instead stores the score per letter, which
+makes it much faster and easier to calculate the score for a word. It
+also stores the letters in lower-case regardless of the case of the
+input letters:
+
+- "a" is worth 1 point.
+- "b" is worth 3 points.
+- "c" is worth 3 points.
+- "d" is worth 2 points.
+- Etc.
+
+Your mission, should you choose to accept it, is to write a program that
+transforms the legacy data format to the shiny new format.
+
+### Notes
+
+A final note about scoring, Scrabble is played around the world in a
+variety of languages, each with its own unique scoring table. For
+example, an "A" is scored at 14 in the Basque-language version of the
+game while being scored at 9 in the Latin-language version.
+
+## Getting Started
+
+Make sure you have read the [getting started with C++](http://help.exercism.io/getting-started-with-cpp.html)
+page on the [exercism help site](http://help.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](http://butunclebob.com/ArticleS.UncleBob.TheThreeRulesOfTdd).
+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.
+
+```C++
+#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](http://en.cppreference.com/)
+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](http://www.slideshare.net/LegalizeAdulthood/c-traps-and-pitfalls-for-c-programmers).
+
+## Source
+
+The Jumpstart Lab team [view source](http://jumpstartlab.com)

cpp/etl/etl_test.cpp

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+#include "etl.h"
+#define BOOST_TEST_MAIN
+#include <boost/test/unit_test.hpp>
+
+namespace boost
+{
+
+// teach Boost.Test how to print std::pair
+template <typename K, typename V>
+inline wrap_stringstream&
+operator<<(wrap_stringstream& wrapped, std::pair<const K, V> const& item)
+{
+    return wrapped << '<' << item.first << ',' << item.second << '>';
+}
+
+}
+
+#define REQUIRE_EQUAL_CONTAINERS(left_, right_) \
+    BOOST_REQUIRE_EQUAL_COLLECTIONS(left_.begin(), left_.end(), right_.begin(), right_.end())
+
+BOOST_AUTO_TEST_CASE(transforms_one_value)
+{
+    const std::map<int, std::vector<char>> old{{1, {'A'}}};
+
+    const auto actual = etl::transform(old);
+
+    const std::map<char, int> expected{{'a', 1}};
+    REQUIRE_EQUAL_CONTAINERS(expected, actual);
+}
+
+#if defined(EXERCISM_RUN_ALL_TESTS)
+BOOST_AUTO_TEST_CASE(transforms_more_values)
+{
+    const std::map<int, std::vector<char>> old{{1, {'A', 'E', 'I', 'O', 'U'}}};
+
+    const auto actual = etl::transform(old);
+
+    const std::map<char, int> expected{{'a', 1}, {'e', 1}, {'i', 1}, {'o', 1}, {'u', 1}};
+    REQUIRE_EQUAL_CONTAINERS(expected, actual);
+}
+
+BOOST_AUTO_TEST_CASE(transforms_more_keys)
+{
+    const std::map<int, std::vector<char>> old{{1, {'A', 'E'}}, {2, {'D', 'G'}}};
+
+    const auto actual = etl::transform(old);
+
+    const std::map<char, int> expected{{'a', 1}, {'e', 1}, {'d', 2}, {'g', 2}};
+    REQUIRE_EQUAL_CONTAINERS(expected, actual);
+}
+
+BOOST_AUTO_TEST_CASE(transforms_a_full_dataset)
+{
+    const std::map<int, std::vector<char>> old{
+        {1, {'A', 'E', 'I', 'O', 'U', 'L', 'N', 'R', 'S', 'T'}},
+        {2, {'D', 'G'}},
+        {3, {'B', 'C', 'M', 'P'}},
+        {4, {'F', 'H', 'V', 'W', 'Y'}},
+        {5, {'K'}},
+        {8, {'J', 'X'}},
+        {10, {'Q', 'Z'}}
+    };
+
+    const auto actual = etl::transform(old);
+
+    const std::map<char, int> expected{
+        {'a', 1}, {'b', 3},  {'c', 3}, {'d', 2}, {'e', 1},
+        {'f', 4}, {'g', 2},  {'h', 4}, {'i', 1}, {'j', 8},
+        {'k', 5}, {'l', 1},  {'m', 3}, {'n', 1}, {'o', 1},
+        {'p', 3}, {'q', 10}, {'r', 1}, {'s', 1}, {'t', 1},
+        {'u', 1}, {'v', 4},  {'w', 4}, {'x', 8}, {'y', 4},
+        {'z', 10}
+    };
+    REQUIRE_EQUAL_CONTAINERS(expected, actual);
+}
+#endif