libchain - C++17 std::string utility chain belt

Usage

Requirements

C++17 compiler (g++/clang++)
    Tested on g++-9 and clang++-9
CMake
make and/or ninja

Instructions

Building

mkdir Release && cd Release
cmake -DCMAKE_BUILD_TYPE=Release ..
cmake --build .

Examples

    #include <iostream>
    
    #include <chain/chain.hpp>
    
    int main()
    {
        using namespace chain;
    
        auto print_parts = [](auto& parts) {
            for (const auto& part : parts)
            {
                std::cout << part << " ";
            }
            std::cout << "\n";
        };
    
        // A simple csv split. split() only allocates space for the std::string_view
        // values that it returns, it does not make any copies of the input data.
        auto parts1 = str::split("1,2,3", ',');
        // parts1 = { "1", "2", "3" }
        print_parts(parts1);
    
        // A split mapped into integers.
        auto parts2 = str::split_map<int64_t>(
            "1,2,3", ',', [](std::string_view part) { return str::to_number<int64_t>(part).value_or(0); });
        // parts2 = { 1, 2, 3 }
        print_parts(parts2);
    
        // A pre-allocated split, for large splits to reduce allocations.
        std::vector<std::string_view> parts3{};
        parts3.reserve(128);
        str::split("1,2,3,...,128", ',', parts3);
        // parts3 = { "1", "2", "3", ... , "128" }
        print_parts(parts3);
    
        // A split with zero allocations.
        str::split_for_each("1,2,3,4,5", ',', [](std::string_view part) {
            // 1, 2, 3, 4, 5
            std::cout << part << ", ";
            // Can optionally provide a lambda that returns -> bool type,
            // returning true continues splitting, returning false stops splitting.
        });
        std::cout << "\n";
    
        // A simple csv join.
        std::vector<int64_t> parts4{1, 2, 3};
        auto                 joined1 = str::join(parts4, ',');
        // joined1 == "1,2,3"
        std::cout << joined1 << "\n";
    
        // A map join which squares its parts first.
        std::vector<int64_t> parts5{1, 2, 3};
        // "1,4,9"
        std::cout << str::map_join(parts5, ',', [](int64_t x) { return x * x; }) << "\n";
    
        // Simple consistent to number api, leverages std::optional instead of exceptions.
        auto value = str::to_number<uint64_t>("420").value_or(0);
        // value == 420
        std::cout << value << "\n";
    
        return 0;
    }

Support

File bug reports, feature requests and questions using GitHub Issues

Readme updates

To edit this file the template is located at .githooks/readme-template.md, editing it directly in the root README.md will be overwritten by the git pre-commit hook which automatically replaces the code portions of this file with the appropriate examples.

Code formatting

This library has a git pre-commit hook which is installed when cmake is invoked. Any files that are commited will automatically have clang-format run on them before.

jbaldwin/libchain