vcpkg/toolsrc/include/vcpkg_Parse.h

#pragma once

#include <memory>
#include <unordered_map>

#include "vcpkg_expected.h"
#include "vcpkg_optional.h"

namespace vcpkg::Parse
{
    struct ParseControlErrorInfo
    {
        std::string name;
        std::vector<std::string> missing_fields;
        std::vector<std::string> extra_fields;
        std::error_code error;
    };

    template<class P>
    using ParseExpected = ExpectedT<std::unique_ptr<P>, std::unique_ptr<ParseControlErrorInfo>>;

    using RawParagraph = std::unordered_map<std::string, std::string>;

    struct ParagraphParser
    {
        ParagraphParser(RawParagraph&& fields) : fields(std::move(fields)) {}

        void required_field(const std::string& fieldname, std::string& out);
        std::string optional_field(const std::string& fieldname);
        std::unique_ptr<ParseControlErrorInfo> error_info(const std::string& name) const;

    private:
        RawParagraph&& fields;
        std::vector<std::string> missing_fields;
    };
}