geode/codegen/Broma/PEGTL-3.2.7/include/tao/pegtl/contrib/integer.hpp
2022-07-30 19:24:03 +03:00

468 lines
16 KiB
C++
Executable file

// Copyright (c) 2019-2022 Dr. Colin Hirsch and Daniel Frey
// Please see LICENSE for license or visit https://github.com/taocpp/PEGTL/
#ifndef TAO_PEGTL_CONTRIB_INTEGER_HPP
#define TAO_PEGTL_CONTRIB_INTEGER_HPP
#if !defined( __cpp_exceptions )
#error "Exception support required for tao/pegtl/contrib/integer.hpp"
#else
#include <cstdint>
#include <cstdlib>
#include <limits>
#include <string_view>
#include <type_traits>
#include "../ascii.hpp"
#include "../parse.hpp"
#include "../parse_error.hpp"
#include "../rules.hpp"
#include "analyze_traits.hpp"
namespace TAO_PEGTL_NAMESPACE
{
struct unsigned_rule_old
: plus< digit >
{
// Pre-3.0 version of this rule.
};
struct unsigned_rule_new
: if_then_else< one< '0' >, not_at< digit >, plus< digit > >
{
// New version that does not allow leading zeros.
};
struct signed_rule_old
: seq< opt< one< '-', '+' > >, plus< digit > >
{
// Pre-3.0 version of this rule.
};
struct signed_rule_new
: seq< opt< one< '-', '+' > >, if_then_else< one< '0' >, not_at< digit >, plus< digit > > >
{
// New version that does not allow leading zeros.
};
struct signed_rule_bis
: seq< opt< one< '-' > >, if_then_else< one< '0' >, not_at< digit >, plus< digit > > >
{};
struct signed_rule_ter
: seq< one< '-', '+' >, if_then_else< one< '0' >, not_at< digit >, plus< digit > > >
{};
namespace internal
{
[[nodiscard]] constexpr bool is_digit( const char c ) noexcept
{
// We don't use std::isdigit() because it might
// return true for other values on MS platforms.
return ( '0' <= c ) && ( c <= '9' );
}
template< typename Integer, Integer Maximum = ( std::numeric_limits< Integer >::max )() >
[[nodiscard]] constexpr bool accumulate_digit( Integer& result, const char digit ) noexcept
{
// Assumes that digit is a digit as per is_digit(); returns false on overflow.
static_assert( std::is_integral_v< Integer > );
constexpr Integer cutoff = Maximum / 10;
constexpr Integer cutlim = Maximum % 10;
const Integer c = digit - '0';
if( ( result > cutoff ) || ( ( result == cutoff ) && ( c > cutlim ) ) ) {
return false;
}
result *= 10;
result += c;
return true;
}
template< typename Integer, Integer Maximum = ( std::numeric_limits< Integer >::max )() >
[[nodiscard]] constexpr bool accumulate_digits( Integer& result, const std::string_view input ) noexcept
{
// Assumes input is a non-empty sequence of digits; returns false on overflow.
for( char c : input ) {
if( !accumulate_digit< Integer, Maximum >( result, c ) ) {
return false;
}
}
return true;
}
template< typename Integer, Integer Maximum = ( std::numeric_limits< Integer >::max )() >
[[nodiscard]] constexpr bool convert_positive( Integer& result, const std::string_view input ) noexcept
{
// Assumes result == 0 and that input is a non-empty sequence of digits; returns false on overflow.
static_assert( std::is_integral_v< Integer > );
return accumulate_digits< Integer, Maximum >( result, input );
}
template< typename Signed >
[[nodiscard]] constexpr bool convert_negative( Signed& result, const std::string_view input ) noexcept
{
// Assumes result == 0 and that input is a non-empty sequence of digits; returns false on overflow.
static_assert( std::is_signed_v< Signed > );
using Unsigned = std::make_unsigned_t< Signed >;
constexpr Unsigned maximum = static_cast< Unsigned >( ( std::numeric_limits< Signed >::max )() ) + 1;
Unsigned temporary = 0;
if( accumulate_digits< Unsigned, maximum >( temporary, input ) ) {
result = static_cast< Signed >( ~temporary ) + 1;
return true;
}
return false;
}
template< typename Unsigned, Unsigned Maximum = ( std::numeric_limits< Unsigned >::max )() >
[[nodiscard]] constexpr bool convert_unsigned( Unsigned& result, const std::string_view input ) noexcept
{
// Assumes result == 0 and that input is a non-empty sequence of digits; returns false on overflow.
static_assert( std::is_unsigned_v< Unsigned > );
return accumulate_digits< Unsigned, Maximum >( result, input );
}
template< typename Signed >
[[nodiscard]] constexpr bool convert_signed( Signed& result, const std::string_view input ) noexcept
{
// Assumes result == 0 and that input is an optional sign followed by a non-empty sequence of digits; returns false on overflow.
static_assert( std::is_signed_v< Signed > );
if( input[ 0 ] == '-' ) {
return convert_negative< Signed >( result, std::string_view( input.data() + 1, input.size() - 1 ) );
}
const auto offset = unsigned( input[ 0 ] == '+' );
return convert_positive< Signed >( result, std::string_view( input.data() + offset, input.size() - offset ) );
}
template< typename ParseInput >
[[nodiscard]] bool match_unsigned( ParseInput& in ) noexcept( noexcept( in.empty() ) )
{
if( !in.empty() ) {
const char c = in.peek_char();
if( is_digit( c ) ) {
in.bump_in_this_line();
if( c == '0' ) {
return in.empty() || ( !is_digit( in.peek_char() ) );
}
while( ( !in.empty() ) && is_digit( in.peek_char() ) ) {
in.bump_in_this_line();
}
return true;
}
}
return false;
}
template< typename ParseInput,
typename Unsigned,
Unsigned Maximum = ( std::numeric_limits< Unsigned >::max )() >
[[nodiscard]] bool match_and_convert_unsigned_with_maximum_throws( ParseInput& in, Unsigned& st )
{
// Assumes st == 0.
if( !in.empty() ) {
char c = in.peek_char();
if( is_digit( c ) ) {
if( c == '0' ) {
in.bump_in_this_line();
return in.empty() || ( !is_digit( in.peek_char() ) );
}
do {
if( !accumulate_digit< Unsigned, Maximum >( st, c ) ) {
throw TAO_PEGTL_NAMESPACE::parse_error( "integer overflow", in );
}
in.bump_in_this_line();
} while( ( !in.empty() ) && is_digit( c = in.peek_char() ) );
return true;
}
}
return false;
}
template< typename ParseInput,
typename Unsigned,
Unsigned Maximum = ( std::numeric_limits< Unsigned >::max )() >
[[nodiscard]] bool match_and_convert_unsigned_with_maximum_nothrow( ParseInput& in, Unsigned& st )
{
// Assumes st == 0.
if( !in.empty() ) {
char c = in.peek_char();
if( c == '0' ) {
if( ( in.size( 2 ) < 2 ) || ( !is_digit( in.peek_char( 1 ) ) ) ) {
in.bump_in_this_line();
return true;
}
return false;
}
if( is_digit( c ) ) {
unsigned b = 0;
do {
if( !accumulate_digit< Unsigned, Maximum >( st, c ) ) {
return false;
}
++b;
} while( ( !in.empty() ) && is_digit( c = in.peek_char( b ) ) );
in.bump_in_this_line( b );
return true;
}
}
return false;
}
} // namespace internal
struct unsigned_action
{
// Assumes that 'in' contains a non-empty sequence of ASCII digits.
template< typename ActionInput, typename Unsigned >
static void apply( const ActionInput& in, Unsigned& st )
{
// This function "only" offers basic exception safety.
st = 0;
if( !internal::convert_unsigned( st, in.string_view() ) ) {
throw parse_error( "unsigned integer overflow", in );
}
}
};
struct unsigned_rule
{
using rule_t = unsigned_rule;
using subs_t = empty_list;
template< typename ParseInput >
[[nodiscard]] static bool match( ParseInput& in ) noexcept( noexcept( in.empty() ) )
{
return internal::match_unsigned( in ); // Does not check for any overflow.
}
};
struct unsigned_rule_with_action
{
using rule_t = unsigned_rule_with_action;
using subs_t = empty_list;
template< apply_mode A,
rewind_mode M,
template< typename... >
class Action,
template< typename... >
class Control,
typename ParseInput,
typename... States >
[[nodiscard]] static auto match( ParseInput& in, States&&... /*unused*/ ) noexcept( noexcept( in.empty() ) ) -> std::enable_if_t< A == apply_mode::nothing, bool >
{
return internal::match_unsigned( in ); // Does not check for any overflow.
}
template< apply_mode A,
rewind_mode M,
template< typename... >
class Action,
template< typename... >
class Control,
typename ParseInput,
typename Unsigned >
[[nodiscard]] static auto match( ParseInput& in, Unsigned& st ) -> std::enable_if_t< ( A == apply_mode::action ) && std::is_unsigned_v< Unsigned >, bool >
{
// This function "only" offers basic exception safety.
st = 0;
return internal::match_and_convert_unsigned_with_maximum_throws( in, st ); // Throws on overflow.
}
};
template< typename Unsigned, Unsigned Maximum >
struct maximum_action
{
// Assumes that 'in' contains a non-empty sequence of ASCII digits.
static_assert( std::is_unsigned_v< Unsigned > );
template< typename ActionInput, typename Unsigned2 >
static void apply( const ActionInput& in, Unsigned2& st )
{
// This function "only" offers basic exception safety.
st = 0;
if( !internal::convert_unsigned< Unsigned, Maximum >( st, in.string_view() ) ) {
throw parse_error( "unsigned integer overflow", in );
}
}
};
template< typename Unsigned, Unsigned Maximum = ( std::numeric_limits< Unsigned >::max )() >
struct maximum_rule
{
using rule_t = maximum_rule;
using subs_t = empty_list;
static_assert( std::is_unsigned_v< Unsigned > );
template< typename ParseInput >
[[nodiscard]] static bool match( ParseInput& in )
{
Unsigned st = 0;
return internal::match_and_convert_unsigned_with_maximum_nothrow< ParseInput, Unsigned, Maximum >( in, st );
}
};
template< typename Unsigned, Unsigned Maximum = ( std::numeric_limits< Unsigned >::max )() >
struct maximum_rule_with_action
{
using rule_t = maximum_rule_with_action;
using subs_t = empty_list;
static_assert( std::is_unsigned_v< Unsigned > );
template< apply_mode A,
rewind_mode M,
template< typename... >
class Action,
template< typename... >
class Control,
typename ParseInput,
typename... States >
[[nodiscard]] static auto match( ParseInput& in, States&&... /*unused*/ ) -> std::enable_if_t< A == apply_mode::nothing, bool >
{
Unsigned st = 0;
return internal::match_and_convert_unsigned_with_maximum_throws< ParseInput, Unsigned, Maximum >( in, st );
}
template< apply_mode A,
rewind_mode M,
template< typename... >
class Action,
template< typename... >
class Control,
typename ParseInput,
typename Unsigned2 >
[[nodiscard]] static auto match( ParseInput& in, Unsigned2& st ) -> std::enable_if_t< ( A == apply_mode::action ) && std::is_same_v< Unsigned, Unsigned2 >, bool >
{
// This function "only" offers basic exception safety.
st = 0;
return internal::match_and_convert_unsigned_with_maximum_throws< ParseInput, Unsigned, Maximum >( in, st );
}
};
struct signed_action
{
// Assumes that 'in' contains a non-empty sequence of ASCII digits,
// with optional leading sign; with sign, in.size() must be >= 2.
template< typename ActionInput, typename Signed >
static void apply( const ActionInput& in, Signed& st )
{
// This function "only" offers basic exception safety.
st = 0;
if( !internal::convert_signed( st, in.string_view() ) ) {
throw parse_error( "signed integer overflow", in );
}
}
};
struct signed_rule
{
using rule_t = signed_rule;
using subs_t = empty_list;
template< typename ParseInput >
[[nodiscard]] static bool match( ParseInput& in ) noexcept( noexcept( in.empty() ) )
{
return TAO_PEGTL_NAMESPACE::parse< signed_rule_new >( in ); // Does not check for any overflow.
}
};
namespace internal
{
template< typename Rule >
struct signed_action_action
: nothing< Rule >
{};
template<>
struct signed_action_action< signed_rule_new >
: signed_action
{};
} // namespace internal
struct signed_rule_with_action
{
using rule_t = signed_rule_with_action;
using subs_t = empty_list;
template< apply_mode A,
rewind_mode M,
template< typename... >
class Action,
template< typename... >
class Control,
typename ParseInput,
typename... States >
[[nodiscard]] static auto match( ParseInput& in, States&&... /*unused*/ ) noexcept( noexcept( in.empty() ) ) -> std::enable_if_t< A == apply_mode::nothing, bool >
{
return TAO_PEGTL_NAMESPACE::parse< signed_rule_new >( in ); // Does not check for any overflow.
}
template< apply_mode A,
rewind_mode M,
template< typename... >
class Action,
template< typename... >
class Control,
typename ParseInput,
typename Signed >
[[nodiscard]] static auto match( ParseInput& in, Signed& st ) -> std::enable_if_t< ( A == apply_mode::action ) && std::is_signed_v< Signed >, bool >
{
return TAO_PEGTL_NAMESPACE::parse< signed_rule_new, internal::signed_action_action >( in, st ); // Throws on overflow.
}
};
template< typename Name >
struct analyze_traits< Name, unsigned_rule >
: analyze_any_traits<>
{};
template< typename Name >
struct analyze_traits< Name, unsigned_rule_with_action >
: analyze_any_traits<>
{};
template< typename Name, typename Integer, Integer Maximum >
struct analyze_traits< Name, maximum_rule< Integer, Maximum > >
: analyze_any_traits<>
{};
template< typename Name, typename Integer, Integer Maximum >
struct analyze_traits< Name, maximum_rule_with_action< Integer, Maximum > >
: analyze_any_traits<>
{};
template< typename Name >
struct analyze_traits< Name, signed_rule >
: analyze_any_traits<>
{};
template< typename Name >
struct analyze_traits< Name, signed_rule_with_action >
: analyze_any_traits<>
{};
} // namespace TAO_PEGTL_NAMESPACE
#endif
#endif