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construct/include/ircd/json/vector.h
2018-02-05 21:24:34 -08:00

165 lines
4.2 KiB
C++

// Matrix Construct
//
// Copyright (C) Matrix Construct Developers, Authors & Contributors
// Copyright (C) 2016-2018 Jason Volk <jason@zemos.net>
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice is present in all copies. The
// full license for this software is available in the LICENSE file.
#pragma once
#define HAVE_IRCD_JSON_VECTOR_H
namespace ircd::json
{
struct vector;
}
/// Interface for non-standard, non-delimited concatenations of objects
///
/// This class parses a "vector of objects" with a similar strategy and
/// interface to that of json::array etc. The elements of the vector are
/// JSON objects delimited only by their structure. This is primarily for
/// test vectors and internal use and should not be used in public facing
/// code.
///
/// As with json::array, the same stateless forward-iteration notice applies
/// here. This object will not perform well for random access.
///
struct ircd::json::vector
:string_view
{
struct const_iterator;
using value_type = const object;
using pointer = value_type *;
using reference = value_type &;
using iterator = const_iterator;
using size_type = size_t;
using difference_type = ptrdiff_t;
const_iterator end() const;
const_iterator begin() const;
const_iterator find(size_t i) const;
size_t count() const;
size_t size() const;
value_type at(const size_t &i) const;
value_type operator[](const size_t &i) const;
using string_view::string_view;
};
struct ircd::json::vector::const_iterator
{
using value_type = const object;
using pointer = value_type *;
using reference = value_type &;
using iterator = const_iterator;
using size_type = size_t;
using difference_type = ptrdiff_t;
using iterator_category = std::forward_iterator_tag;
protected:
friend class vector;
const char *start;
const char *stop;
object state;
const_iterator(const char *const &start, const char *const &stop)
:start{start}
,stop{stop}
{}
public:
value_type *operator->() const { return &state; }
value_type &operator*() const { return *operator->(); }
const_iterator &operator++();
friend bool operator==(const const_iterator &, const const_iterator &);
friend bool operator!=(const const_iterator &, const const_iterator &);
friend bool operator<=(const const_iterator &, const const_iterator &);
friend bool operator>=(const const_iterator &, const const_iterator &);
friend bool operator<(const const_iterator &, const const_iterator &);
friend bool operator>(const const_iterator &, const const_iterator &);
};
inline ircd::json::vector::value_type
ircd::json::vector::operator[](const size_t &i)
const
{
const auto it(find(i));
return it != end()? *it : object{};
}
inline ircd::json::vector::value_type
ircd::json::vector::at(const size_t &i)
const
{
const auto it(find(i));
return likely(it != end())? *it : throw not_found("indice %zu", i);
}
inline ircd::json::vector::const_iterator
ircd::json::vector::find(size_t i)
const
{
auto it(begin());
for(; it != end() && i; ++it, i--);
return it;
}
__attribute__((warning("Taking string_view::size() not the count() of vector elements")))
inline size_t
ircd::json::vector::size()
const
{
return count();
}
inline size_t
ircd::json::vector::count()
const
{
return std::distance(begin(), end());
}
inline bool
ircd::json::operator==(const vector::const_iterator &a, const vector::const_iterator &b)
{
return a.start == b.start;
}
inline bool
ircd::json::operator!=(const vector::const_iterator &a, const vector::const_iterator &b)
{
return a.start != b.start;
}
inline bool
ircd::json::operator<=(const vector::const_iterator &a, const vector::const_iterator &b)
{
return a.start <= b.start;
}
inline bool
ircd::json::operator>=(const vector::const_iterator &a, const vector::const_iterator &b)
{
return a.start >= b.start;
}
inline bool
ircd::json::operator<(const vector::const_iterator &a, const vector::const_iterator &b)
{
return a.start < b.start;
}
inline bool
ircd::json::operator>(const vector::const_iterator &a, const vector::const_iterator &b)
{
return a.start > b.start;
}