view.hpp

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#ifndef __DCONV_VIEW_HPP__
#define __DCONV_VIEW_HPP__
 
// C++.
#include <string>
 
// C.
#include <cstring>
#include <cstddef>
 
#define likely(x)   __builtin_expect((x), 1)
#define unlikely(x) __builtin_expect((x), 0)
 
namespace dconv
{
    class View
    {
    public:
        explicit constexpr View (const char * s, size_t count)
        : _pos (s)
        , _end (s ? s + count : s)
        {
        }
 
        constexpr View (const char * first, const char * last)
        : _pos (first)
        , _end (last)
        {
        }
 
        explicit View (const char * s)
        : _pos (s)
        , _end (s ? s + std::char_traits <char>::length (s) : s)
        {
        }
 
        View (const View& other) noexcept = default;
 
        View& operator= (const View& other) noexcept = default;
 
        View (View&& other) noexcept = default;
 
        View& operator=(View&& other) noexcept = default;
 
        ~View () = default;
 
        inline int peek () const noexcept
        {
            if (likely (_pos < _end))
            {
                return static_cast <unsigned char> (*_pos);
            }
            return std::char_traits <char>::eof ();
        }
 
        inline int get () noexcept
        {
            if (likely (_pos < _end))
            {
                return static_cast <unsigned char> (*_pos++);
            }
            return std::char_traits <char>::eof ();
        }
 
        inline bool getIf (char expected) noexcept
        {
            if (likely (_pos < _end) && (*_pos == expected))
            {
                ++_pos;
                return true;
            }
            return false;
        }
 
        inline bool getIfNoCase (char expected) noexcept
        {
            if (likely (_pos < _end))
            {
                const char c = *_pos;
                if ((c | 32) == (expected | 32))
                {
                    ++_pos;
                    return true;
                }
            }
            return false;
        }
 
        inline const char * data () const noexcept
        {
            return _pos;
        }
 
        inline size_t size () const noexcept
        {
            return _end - _pos;
        }
 
    private:
        const char * _pos = nullptr;
 
        const char * _end = nullptr;
    };
}
 
#endif