mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2024-11-22 15:40:19 +00:00
82 lines
3.4 KiB
C++
82 lines
3.4 KiB
C++
/*
|
|
* Copyright (c) 2022, David Tuin <davidot@serenityos.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <AK/StringView.h>
|
|
|
|
namespace AK {
|
|
|
|
static constexpr char floating_point_decimal_separator = '.';
|
|
|
|
enum class FloatingPointError {
|
|
None,
|
|
NoOrInvalidInput,
|
|
OutOfRange,
|
|
RoundedDownToZero
|
|
};
|
|
|
|
template<FloatingPoint T>
|
|
struct FloatingPointParseResults {
|
|
char const* end_ptr { nullptr };
|
|
FloatingPointError error = FloatingPointError::None;
|
|
T value {};
|
|
|
|
[[nodiscard]] bool parsed_value() const
|
|
{
|
|
// All other errors do indicate out of range but did produce a valid value.
|
|
return error != FloatingPointError::NoOrInvalidInput;
|
|
}
|
|
};
|
|
|
|
/// This function finds the first floating point within [start, end). The accepted format is
|
|
/// intentionally as lenient as possible. If your format is stricter you must validate it
|
|
/// first. The format accepts:
|
|
/// - An optional sign, both + and - are supported
|
|
/// - 0 or more decimal digits, with leading zeros allowed [1]
|
|
/// - A decimal point '.', which can have no digits after it
|
|
/// - 0 or more decimal digits, unless the first digits [1] doesn't have any digits,
|
|
/// then this must have at least one
|
|
/// - An exponent 'e' or 'E' followed by an optional sign '+' or '-' and at least one digit
|
|
/// This function additionally detects out of range values which have been rounded to
|
|
/// [-]infinity or 0 and gives the next character to read after the floating point.
|
|
template<FloatingPoint T = double>
|
|
FloatingPointParseResults<T> parse_first_floating_point(char const* start, char const* end);
|
|
|
|
/// This function finds the first floating point starting at start up to the first '\0'.
|
|
/// The format is identical to parse_first_floating_point above.
|
|
template<FloatingPoint T = double>
|
|
FloatingPointParseResults<T> parse_first_floating_point_until_zero_character(char const* start);
|
|
|
|
/// This function will return either a floating point, or an empty optional if the given StringView
|
|
/// does not a floating point or contains more characters beyond the floating point. For the format
|
|
/// check the comment on parse_first_floating_point.
|
|
template<FloatingPoint T = double>
|
|
Optional<T> parse_floating_point_completely(char const* start, char const* end);
|
|
|
|
/// This function finds the first floating point as a hex float within [start, end).
|
|
/// The accepted format is intentionally as lenient as possible. If your format is
|
|
/// stricter you must validate it first. The format accepts:
|
|
/// - An optional sign, both + and - are supported
|
|
/// - Optionally either 0x or OX
|
|
/// - 0 or more hexadecimal digits, with leading zeros allowed [1]
|
|
/// - A decimal point '.', which can have no digits after it
|
|
/// - 0 or more hexadecimal digits, unless the first digits [1] doesn't have any digits,
|
|
/// then this must have at least one
|
|
/// - An exponent 'p' or 'P' followed by an optional sign '+' or '-' and at least one decimal digit
|
|
/// NOTE: The exponent is _not_ hexadecimal and gives powers of 2 not 16.
|
|
/// This function additionally detects out of range values which have been rounded to
|
|
/// [-]infinity or 0 and gives the next character to read after the floating point.
|
|
template<FloatingPoint T = double>
|
|
FloatingPointParseResults<T> parse_first_hexfloat_until_zero_character(char const* start);
|
|
|
|
}
|
|
|
|
#if USING_AK_GLOBALLY
|
|
using AK::parse_first_floating_point;
|
|
using AK::parse_first_hexfloat_until_zero_character;
|
|
using AK::parse_floating_point_completely;
|
|
#endif
|