construct/include/ircd/rfc1459.h

/*
 * charybdis: 21st Century IRC++d
 * rfc1459.h: RFC1459 Specification API
 *
 * Copyright (C) 2016 Charybdis Development Team
 * Copyright (C) 2016 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */

#pragma once
#define HAVE_IRCD_RFC1459_H

namespace ircd      {
namespace rfc1459   {

IRCD_EXCEPTION(ircd::error, error)
IRCD_EXCEPTION(error, syntax_error)

namespace character
{
	enum attr
	:uint
	{
		PRINT    = 0x00000001,
		CNTRL    = 0x00000002,
		ALPHA    = 0x00000004,
		PUNCT    = 0x00000008,
		DIGIT    = 0x00000010,
		SPACE    = 0x00000020,
		NICK     = 0x00000040,
		CHAN     = 0x00000080,
		KWILD    = 0x00000100,
		CHANPFX  = 0x00000200,
		USER     = 0x00000400,
		HOST     = 0x00000800,
		NONEOS   = 0x00001000,
		SERV     = 0x00002000,
		EOL      = 0x00004000,
		MWILD    = 0x00008000,
		LET      = 0x00010000,    // an actual letter
		FCHAN    = 0x00020000,    // a 'fake' channel char
	};

	using attr_t = std::underlying_type<attr>::type;

	extern const std::array<attr_t, 256> attrs;
	extern const std::array<unsigned char, 256> tolower_tab;
	extern const std::array<unsigned char, 256> toupper_tab;

	// Tests
	bool is(const uint8_t &c, const attr &attr);

	// Transforms
	const uint8_t &tolower(const uint8_t &c);
	const uint8_t &toupper(const uint8_t &c);

	// Get all characters for an attribute mask
	size_t gather(const attr &attr, uint8_t *const &buf, const size_t &max);
	std::string gather(const attr &attr);

	// Like gather() but with special considerations for boost::spirit's char_()
	size_t charset(const attr &attr, uint8_t *const &buf, const size_t &max);
	std::string charset(const attr &attr);
}

using character::is;
using character::toupper;
using character::tolower;
using character::gather;

inline bool is_print(const char &c)              { return is(c, character::PRINT);                 }
inline bool is_host(const char &c)               { return is(c, character::HOST);                  }
inline bool is_user(const char &c)               { return is(c, character::USER);                  }
inline bool is_chan(const char &c)               { return is(c, character::CHAN);                  }
inline bool is_chan_prefix(const char &c)        { return is(c, character::CHANPFX);               }
inline bool is_fake_chan(const char &c)          { return is(c, character::FCHAN);                 }
inline bool is_kwild(const char &c)              { return is(c, character::KWILD);                 }
inline bool is_mwild(const char &c)              { return is(c, character::MWILD);                 }
inline bool is_nick(const char &c)               { return is(c, character::NICK);                  }
inline bool is_letter(const char &c)             { return is(c, character::LET);                   }
inline bool is_digit(const char &c)              { return is(c, character::DIGIT);                 }
inline bool is_cntrl(const char &c)              { return is(c, character::CNTRL);                 }
inline bool is_alpha(const char &c)              { return is(c, character::ALPHA);                 }
inline bool is_space(const char &c)              { return is(c, character::SPACE);                 }
inline bool is_noneos(const char &c)             { return is(c, character::NONEOS);                }
inline bool is_eol(const char &c)                { return is(c, character::EOL);                   }
inline bool is_serv(const char &c)               { return is(c, character::SERV) || is_nick(c);    }
inline bool is_id(const char &c)                 { return is_digit(c) || is_letter(c);             }
inline bool is_alnum(const char &c)              { return is_digit(c) || is_alpha(c);              }
inline bool is_punct(const char &c)              { return !is_cntrl(c) && !is_alnum(c);            }
inline bool is_lower(const char &c)              { return is_alpha(c) && uint8_t(c) > 0x5f;        }
inline bool is_upper(const char &c)              { return is_alpha(c) && uint8_t(c) < 0x60;        }
inline bool is_graph(const char &c)              { return is_print(c) && uint8_t(c) != 0x32;       }
inline bool is_ascii(const char &c)              { return uint8_t(c) < 0x80;                       }
inline bool is_xdigit(const char &c)
{
	return is_digit(c) || ('a' <= c && c <= 'f') || ('A' <= c && c <= 'F');
}

struct less
{
	bool operator()(const char *const &a, const char *const &b) const;
	bool operator()(const std::string &a, const std::string &b) const;
	bool operator()(const std::string_view &a, const std::string_view &b) const;
};

struct nick
:string_view
{
	using string_view::string_view;
};

struct user
:string_view
{
	using string_view::string_view;
};

struct host
:string_view
{
	using string_view::string_view;
};

struct cmd
:string_view
{
	using string_view::string_view;
};

struct parv
:std::vector<string_view>
{
	using std::vector<string_view>::vector;
};

struct pfx
{
	struct nick nick;
	struct user user;
	struct host host;

	bool empty() const;
};

struct line
{
	struct pfx pfx;
	struct cmd cmd;
	struct parv parv;

	bool empty() const;
	auto operator[](const size_t &pos) const     { return parv.at(pos);                            }
	auto operator[](const size_t &pos)           { return parv.at(pos);                            }

	line(const char *&start, const char *const &stop);
	line() = default;
};

std::ostream &operator<<(std::ostream &, const pfx &);
std::ostream &operator<<(std::ostream &, const cmd &);
std::ostream &operator<<(std::ostream &, const parv &);
std::ostream &operator<<(std::ostream &, const line &);   // unterminated


inline bool
less::operator()(const std::string_view &a,
                 const std::string_view &b)
const
{
	return std::lexicographical_compare(begin(a), end(a), begin(b), end(b), []
	(const char &a, const char &b)
	{
		return tolower(a) < tolower(b);
	});
}

inline bool
less::operator()(const std::string &a,
                 const std::string &b)
const
{
	return std::lexicographical_compare(begin(a), end(a), begin(b), end(b), []
	(const char &a, const char &b)
	{
		return tolower(a) < tolower(b);
	});
}

inline bool
less::operator()(const char *const &a,
                 const char *const &b)
const
{
	return std::lexicographical_compare(a, a + strlen(a), b, b + strlen(b), []
	(const char &a, const char &b)
	{
		return tolower(a) < tolower(b);
	});
}

inline const uint8_t &
character::tolower(const uint8_t &c)
{
	return tolower_tab[c];
}

inline const uint8_t &
character::toupper(const uint8_t &c)
{
	return toupper_tab[c];
}

inline bool
character::is(const uint8_t &c,
              const attr &attr)
{
	return (attrs[c] & attr) == attr;
}

} // namespace rfc1459
} // namespace ircd