feat: add list-ops exercise

config.json

@@ -1109,6 +1109,14 @@
         "prerequisites": [],
         "difficulty": 5
       },
+      {
+        "slug": "list-ops",
+        "name": "List Ops",
+        "uuid": "9498d0bf-c411-4b3b-b0c7-a063aa7f0acc",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 5
+      },
       {
         "slug": "knapsack",
         "name": "Knapsack",

exercises/practice/list-ops/.docs/instructions.md

@@ -0,0 +1,19 @@
+# Instructions
+
+Implement basic list operations.
+
+In functional languages list operations like `length`, `map`, and `reduce` are very common.
+Implement a series of basic list operations, without using existing functions.
+
+The precise number and names of the operations to be implemented will be track dependent to avoid conflicts with existing names, but the general operations you will implement include:
+
+- `append` (_given two lists, add all items in the second list to the end of the first list_);
+- `concatenate` (_given a series of lists, combine all items in all lists into one flattened list_);
+- `filter` (_given a predicate and a list, return the list of all items for which `predicate(item)` is True_);
+- `length` (_given a list, return the total number of items within it_);
+- `map` (_given a function and a list, return the list of the results of applying `function(item)` on all items_);
+- `foldl` (_given a function, a list, and initial accumulator, fold (reduce) each item into the accumulator from the left_);
+- `foldr` (_given a function, a list, and an initial accumulator, fold (reduce) each item into the accumulator from the right_);
+- `reverse` (_given a list, return a list with all the original items, but in reversed order_).
+
+Note, the ordering in which arguments are passed to the fold functions (`foldl`, `foldr`) is significant.

exercises/practice/list-ops/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "vaeng"
+  ],
+  "files": {
+    "solution": [
+      "list_ops.cpp",
+      "list_ops.h"
+    ],
+    "test": [
+      "list_ops_test.cpp"
+    ],
+    "example": [
+      ".meta/example.cpp",
+      ".meta/example.h"
+    ]
+  },
+  "blurb": "Implement basic list operations."
+}

exercises/practice/list-ops/.meta/example.cpp

@@ -0,0 +1,5 @@
+#include "list_ops.h"
+
+namespace list_ops {
+
+}  // namespace list_ops

exercises/practice/list-ops/.meta/example.h

@@ -0,0 +1,82 @@
+#pragma once
+
+#include <functional>
+#include <vector>
+
+namespace list_ops {
+
+template <typename T>
+void append(std::vector<T>& left, const std::vector<T>& right) {
+    for (auto element : right) {
+        left.emplace_back(element);
+    }
+}
+
+template <typename T>
+std::vector<T> concat(const std::vector<std::vector<T>>& input) {
+    std::vector<T> result{};
+    for (auto vec : input) {
+        for (auto element : vec) {
+            result.emplace_back(element);
+        }
+    }
+    return result;
+}
+
+template <typename T, typename S>
+std::vector<T> filter(const std::vector<T>& input, S&& func) {
+    std::vector<T> result{};
+    for (auto element : input) {
+        if (func(element)) {
+            result.emplace_back(element);
+        }
+    }
+    return result;
+}
+
+template <typename T>
+size_t length(const std::vector<T>& input) {
+    size_t counter{};
+    for ([[maybe_unused]] const auto& element : input) {
+        ++counter;
+    }
+    return counter;
+}
+
+template <typename T, typename S>
+std::vector<T> map(const std::vector<T>& input, S&& func) {
+    std::vector<T> result{};
+    for (auto element : input) {
+        result.emplace_back(func(element));
+    }
+    return result;
+}
+
+template <typename T, typename S>
+T foldl(const std::vector<T>& input, T initial_value, S&& func) {
+    T accumulator{initial_value};
+    for (auto element : input) {
+        accumulator = func(accumulator, element);
+    }
+    return accumulator;
+}
+
+template <typename T, typename S>
+T foldr(const std::vector<T>& input, T initial_value, S&& func) {
+    T accumulator{initial_value};
+    for (unsigned i = input.size(); i-- > 0;) {
+        accumulator = func(accumulator, input.at(i));
+    }
+    return accumulator;
+}
+
+template <typename T>
+std::vector<T> reverse(const std::vector<T>& input) {
+    std::vector<T> result{};
+    for (unsigned i = input.size(); i-- > 0;) {
+        result.emplace_back(input.at(i));
+    }
+    return result;
+}
+
+}  // namespace list_ops

exercises/practice/list-ops/.meta/tests.toml

@@ -0,0 +1,106 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[485b9452-bf94-40f7-a3db-c3cf4850066a]
+description = "append entries to a list and return the new list -> empty lists"
+
+[2c894696-b609-4569-b149-8672134d340a]
+description = "append entries to a list and return the new list -> list to empty list"
+
+[e842efed-3bf6-4295-b371-4d67a4fdf19c]
+description = "append entries to a list and return the new list -> empty list to list"
+
+[71dcf5eb-73ae-4a0e-b744-a52ee387922f]
+description = "append entries to a list and return the new list -> non-empty lists"
+
+[28444355-201b-4af2-a2f6-5550227bde21]
+description = "concatenate a list of lists -> empty list"
+
+[331451c1-9573-42a1-9869-2d06e3b389a9]
+description = "concatenate a list of lists -> list of lists"
+
+[d6ecd72c-197f-40c3-89a4-aa1f45827e09]
+description = "concatenate a list of lists -> list of nested lists"
+
+[0524fba8-3e0f-4531-ad2b-f7a43da86a16]
+description = "filter list returning only values that satisfy the filter function -> empty list"
+
+[88494bd5-f520-4edb-8631-88e415b62d24]
+description = "filter list returning only values that satisfy the filter function -> non-empty list"
+
+[1cf0b92d-8d96-41d5-9c21-7b3c37cb6aad]
+description = "returns the length of a list -> empty list"
+
+[d7b8d2d9-2d16-44c4-9a19-6e5f237cb71e]
+description = "returns the length of a list -> non-empty list"
+
+[c0bc8962-30e2-4bec-9ae4-668b8ecd75aa]
+description = "return a list of elements whose values equal the list value transformed by the mapping function -> empty list"
+
+[11e71a95-e78b-4909-b8e4-60cdcaec0e91]
+description = "return a list of elements whose values equal the list value transformed by the mapping function -> non-empty list"
+
+[613b20b7-1873-4070-a3a6-70ae5f50d7cc]
+description = "folds (reduces) the given list from the left with a function -> empty list"
+include = false
+
+[e56df3eb-9405-416a-b13a-aabb4c3b5194]
+description = "folds (reduces) the given list from the left with a function -> direction independent function applied to non-empty list"
+include = false
+
+[d2cf5644-aee1-4dfc-9b88-06896676fe27]
+description = "folds (reduces) the given list from the left with a function -> direction dependent function applied to non-empty list"
+include = false
+
+[36549237-f765-4a4c-bfd9-5d3a8f7b07d2]
+description = "folds (reduces) the given list from the left with a function -> empty list"
+reimplements = "613b20b7-1873-4070-a3a6-70ae5f50d7cc"
+
+[7a626a3c-03ec-42bc-9840-53f280e13067]
+description = "folds (reduces) the given list from the left with a function -> direction independent function applied to non-empty list"
+reimplements = "e56df3eb-9405-416a-b13a-aabb4c3b5194"
+
+[d7fcad99-e88e-40e1-a539-4c519681f390]
+description = "folds (reduces) the given list from the left with a function -> direction dependent function applied to non-empty list"
+reimplements = "d2cf5644-aee1-4dfc-9b88-06896676fe27"
+
+[aeb576b9-118e-4a57-a451-db49fac20fdc]
+description = "folds (reduces) the given list from the right with a function -> empty list"
+include = false
+
+[c4b64e58-313e-4c47-9c68-7764964efb8e]
+description = "folds (reduces) the given list from the right with a function -> direction independent function applied to non-empty list"
+include = false
+
+[be396a53-c074-4db3-8dd6-f7ed003cce7c]
+description = "folds (reduces) the given list from the right with a function -> direction dependent function applied to non-empty list"
+include = false
+
+[17214edb-20ba-42fc-bda8-000a5ab525b0]
+description = "folds (reduces) the given list from the right with a function -> empty list"
+reimplements = "aeb576b9-118e-4a57-a451-db49fac20fdc"
+
+[e1c64db7-9253-4a3d-a7c4-5273b9e2a1bd]
+description = "folds (reduces) the given list from the right with a function -> direction independent function applied to non-empty list"
+reimplements = "c4b64e58-313e-4c47-9c68-7764964efb8e"
+
+[8066003b-f2ff-437e-9103-66e6df474844]
+description = "folds (reduces) the given list from the right with a function -> direction dependent function applied to non-empty list"
+reimplements = "be396a53-c074-4db3-8dd6-f7ed003cce7c"
+
+[94231515-050e-4841-943d-d4488ab4ee30]
+description = "reverse the elements of the list -> empty list"
+
+[fcc03d1e-42e0-4712-b689-d54ad761f360]
+description = "reverse the elements of the list -> non-empty list"
+
+[40872990-b5b8-4cb8-9085-d91fc0d05d26]
+description = "reverse the elements of the list -> list of lists is not flattened"

exercises/practice/list-ops/CMakeLists.txt

@@ -0,0 +1,64 @@
+# Get the exercise name from the current directory
+get_filename_component(exercise ${CMAKE_CURRENT_SOURCE_DIR} NAME)
+
+# Basic CMake project
+cmake_minimum_required(VERSION 3.5.1)
+
+# Name the project after the exercise
+project(${exercise} CXX)
+
+# 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 ${file}.cpp)
+else()
+    set(exercise_cpp "")
+endif()
+
+# Use the common Catch library?
+if(EXERCISM_COMMON_CATCH)
+    # For Exercism track development only
+    add_executable(${exercise} ${file}_test.cpp ${exercise_cpp} ${file}.h $<TARGET_OBJECTS:catchlib>)
+elseif(EXERCISM_TEST_SUITE)
+    # The Exercism test suite is being run, the Docker image already
+    # includes a pre-built version of Catch.
+    find_package(Catch2 REQUIRED)
+    add_executable(${exercise} ${file}_test.cpp ${exercise_cpp} ${file}.h)
+    target_link_libraries(${exercise} PRIVATE Catch2::Catch2WithMain)
+    # When Catch is installed system wide we need to include a different
+    # header, we need this define to use the correct one.
+    target_compile_definitions(${exercise} PRIVATE EXERCISM_TEST_SUITE)
+else()
+    # Build executable from sources and headers
+    add_executable(${exercise} ${file}_test.cpp ${exercise_cpp} ${file}.h test/tests-main.cpp)
+endif()
+
+set_target_properties(${exercise} PROPERTIES
+    CXX_STANDARD 17
+    CXX_STANDARD_REQUIRED OFF
+    CXX_EXTENSIONS OFF
+)
+
+set(CMAKE_BUILD_TYPE Debug)
+
+if("${CMAKE_CXX_COMPILER_ID}" MATCHES "(GNU|Clang)")
+    set_target_properties(${exercise} PROPERTIES
+        COMPILE_FLAGS "-Wall -Wextra -Wpedantic -Werror"
+    )
+endif()
+
+# Configure to run all the tests?
+if(${EXERCISM_RUN_ALL_TESTS})
+    target_compile_definitions(${exercise} PRIVATE EXERCISM_RUN_ALL_TESTS)
+endif()
+
+# 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_target(test_${exercise} ALL DEPENDS ${exercise} COMMAND ${exercise})

exercises/practice/list-ops/list_ops.cpp

@@ -0,0 +1,5 @@
+#include "list_ops.h"
+
+namespace list_ops {
+
+}  // namespace list_ops

exercises/practice/list-ops/list_ops.h

@@ -0,0 +1,5 @@
+#pragma once
+
+namespace list_ops {
+
+}  // namespace list_ops