Refactor structure (#3)

- put sorting network implementations in separate files
- put tests for each network implementation in a separate file (allows for faster compilation)
- add githook to automatically create a single header implementation
- update readme
- add .clangformat

Author: quxflux

.clang-format

@@ -0,0 +1,68 @@
+---
+AlignConsecutiveAssignments: false
+AllowShortFunctionsOnASingleLine: Inline
+AllowShortIfStatementsOnASingleLine: Never
+AllowShortLambdasOnASingleLine: Inline
+AllowShortLoopsOnASingleLine: 'false'
+AlignConsecutiveDeclarations: 'false'
+AlwaysBreakAfterDefinitionReturnType: None
+AlwaysBreakAfterReturnType: None
+AlwaysBreakTemplateDeclarations: Yes
+BreakBeforeBinaryOperators: None
+BreakBeforeBraces: Custom
+BraceWrapping:
+  SplitEmptyRecord: false
+  AfterClass: true
+  AfterFunction: true
+  AfterNamespace: true
+  AfterStruct: true
+  AfterControlStatement: Always 
+  AfterEnum: true
+  AfterUnion: true
+  AfterExternBlock: true
+  BeforeCatch: true
+  BeforeElse: false
+  # BeforeLambdaBody: false
+  # BeforeWhile: false
+  SplitEmptyFunction: false
+  SplitEmptyNamespace: false
+BreakInheritanceList: BeforeColon
+BreakStringLiterals: 'true'
+ColumnLimit: '120'
+CompactNamespaces: 'false'
+ConstructorInitializerIndentWidth: '2'
+ContinuationIndentWidth: '2'
+DerivePointerAlignment: 'true'
+DisableFormat: 'false'
+IncludeBlocks: Regroup
+IndentCaseLabels: 'true'
+IndentWidth: '2'
+IndentWrappedFunctionNames: 'true'
+KeepEmptyLinesAtTheStartOfBlocks: 'false'
+Language: Cpp
+MaxEmptyLinesToKeep: '2'
+NamespaceIndentation: All
+PenaltyBreakAssignment: '50'
+PointerAlignment: Left
+ReflowComments: 'true'
+SortIncludes: 'false'
+SortUsingDeclarations: 'false'
+SpaceAfterCStyleCast: 'false'
+SpaceAfterLogicalNot: 'false'
+SpaceAfterTemplateKeyword: 'false'
+SpaceBeforeAssignmentOperators: 'true'
+SpaceBeforeCpp11BracedList: 'false'
+SpaceBeforeCtorInitializerColon: 'true'
+SpaceBeforeInheritanceColon: 'true'
+SpaceBeforeParens: ControlStatements
+SpaceInEmptyParentheses: 'false'
+SpacesBeforeTrailingComments: '2'
+SpacesInAngles: 'false'
+SpacesInCStyleCastParentheses: 'false'
+SpacesInParentheses: 'false'
+SpacesInSquareBrackets: 'false'
+Standard: Auto
+TabWidth: '0'
+UseTab: Never
+
+...

.githooks/pre-push

@@ -0,0 +1,12 @@
+#!/bin/sh
+
+echo 'Creating single header implementation'
+LOCAL_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
+py "$LOCAL_DIR/../scripts/make_single_header_impl.py"
+
+git add "single_header_impl"
+
+if ! git diff --quiet --cached single_header_impl; then
+    echo "Contents of single_header_impl changed. Please check whether these changes are correct."
+    exit -1
+fi

.gitignore

@@ -1,2 +1,4 @@
 .idea
-cmake-build*
+cmake-build*
+.vs
+out

CMakeLists.txt

@@ -39,10 +39,15 @@ endif()
 if(BUILD_TESTS)
   find_package(GTest REQUIRED)
   include(GoogleTest)
-  enable_testing()
 
-  add_executable(${SN_TESTS_EXECUTABLE_NAME} "test/test_case_gen.h" "test/sorting_network_tests.cpp")
+  add_executable(${SN_TESTS_EXECUTABLE_NAME}
+  "test/test_base.h"
+  "test/test_batcher_odd_even_merge_sort.cpp"
+  "test/test_bitonic_merge_sort.cpp"
+  "test/test_bose_nelson_sort.cpp"
+  "test/test_bubble_sort.cpp"
+  "test/test_insertion_sort.cpp"
+  "test/test_size_optimized_sort.cpp"
+  )
   target_link_libraries(${SN_TESTS_EXECUTABLE_NAME} GTest::gtest GTest::gtest_main metal project_options)
-
-  gtest_discover_tests(${SN_TESTS_EXECUTABLE_NAME})
 endif()

README.md

@@ -22,7 +22,7 @@ A single class `sorting_network` is available which encapsulates the implementat
 Following listing gives a few examples:
 
 ```cpp
-#include <sorting_network_cpp/sorting_network.hpp>
+#include <sorting_network_cpp/sorting_network.h>
 
 #include <array>
 #include <cstdint>
@@ -57,7 +57,7 @@ void example()
     // may be passed as follows:
 
     // custom comparators
-    sorting_network<N>{}(data, compare_and_swap<int, std::less<int>>{});
+    sorting_network<N>{}(data, compare_and_swap<int, std::less<>>{});
 
     // function objects
     struct predicate
@@ -90,20 +90,23 @@ quxflux::sorting_net::sorting_network<N, quxflux::sorting_net::type::bitonic_mer
 The compare and swap operation is the fundamental element a sorting network is composed of. The default implementation works well on scalar types, but if you want to specify a custom implementation (e.g. when hardware intrinsics should be used) you may do this by providing a compare and swap functor to the `sorting_network::operator()` as in following example:
 
 ```cpp
-#include <sorting_network_cpp/sorting_network.hpp>
+#include <sorting_network_cpp/sorting_network.h>
 
 #include <array>
 
 void example(std::array<float,3>& arr)
 {
-  quxflux::sorting_net::sorting_network<3>{}(arr, [](float& a, float& b){
+  quxflux::sorting_net::sorting_network<3>{}(arr.begin(), [](float& a, float& b){
     const auto b_cpy = b;
     b = std::max(a, b);
     a = std::min(a, b_cpy);
   });
 }
 ```
 
+## Single header implementation
+A single header implementation is available which allows experimenting with the sorting networks on [godbolt](https://godbolt.org/z/69WMqMY3c).
+
 ## Requirements
 A compiler with C++17 support
 
@@ -114,6 +117,11 @@ For the bare sorting functionality no dependencies are required. If you want to
 * Depending on the implementation of the comparator the performance advantage of a sorting net compared to a regular sorting algorithm (e.g. `std::sort`) may diminish or even result in worse performance. This can be seen in the [interactive benchmark results overview](https://raw.githack.com/quxflux/sorting_network_cpp/master/doc/data_explorer.htm) for the data type `Vec2i Z-order` which causes in most cases all variants of sorting networks being outperformed by `std::sort` (see [src/benchmark.cpp](src/benchmark.cpp) for the implementation of the aforementioned data type).
 * msvc will fail compiling larger `insertion_sort` networks in certain (unknown) configurations with `fatal error C1202: recursive type or function dependency context too complex`
 
+## Development notes
+* A pre-push [githook](https://git-scm.com/docs/githooks) is available in [.githooks](./.githooks/) which will automatically create the single header implementation. 
+To enable the hook execute 
+`git config --local core.hooksPath .githooks` in the repository directory (python required)
+
 ## References / Acknowledgements
 * ["A Sorting Problem"](https://dl.acm.org/doi/pdf/10.1145/321119.321126) by Bose et al.
 * ["Sorting networks and their applications"](https://core.ac.uk/download/pdf/192393620.pdf) by Batcher
@@ -125,4 +133,4 @@ For the bare sorting functionality no dependencies are required. If you want to
 * [Chart.js](https://www.chartjs.org/) and [Papa Parse](https://www.papaparse.com/) for the visualization of benchmark results
 
 ## License
-[GPLv3](LICENSE)
+[GPLv3](LICENSE)