mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2024-08-17 09:20:28 +03:00
284 lines
8.0 KiB
C++
284 lines
8.0 KiB
C++
/*
|
|
* Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
|
|
* Copyright (c) 2021, Max Wipfli <mail@maxwipfli.ch>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <AK/Format.h>
|
|
#include <AK/StringView.h>
|
|
#include <AK/Types.h>
|
|
|
|
#ifndef KERNEL
|
|
# include <AK/DeprecatedString.h>
|
|
#endif
|
|
|
|
namespace AK {
|
|
|
|
class Utf8View;
|
|
|
|
class Utf8CodePointIterator {
|
|
friend class Utf8View;
|
|
|
|
public:
|
|
Utf8CodePointIterator() = default;
|
|
~Utf8CodePointIterator() = default;
|
|
|
|
bool operator==(Utf8CodePointIterator const&) const = default;
|
|
bool operator!=(Utf8CodePointIterator const&) const = default;
|
|
Utf8CodePointIterator& operator++();
|
|
u32 operator*() const;
|
|
// NOTE: This returns {} if the peek is at or past EOF.
|
|
Optional<u32> peek(size_t offset = 0) const;
|
|
|
|
ssize_t operator-(Utf8CodePointIterator const& other) const
|
|
{
|
|
return m_ptr - other.m_ptr;
|
|
}
|
|
|
|
u8 const* ptr() const { return m_ptr; }
|
|
|
|
// Note : These methods return the information about the underlying UTF-8 bytes.
|
|
// If the UTF-8 string encoding is not valid at the iterator's position, then the underlying bytes might be different from the
|
|
// decoded character's re-encoded bytes (which will be an `0xFFFD REPLACEMENT CHARACTER` with an UTF-8 length of three bytes).
|
|
// If your code relies on the decoded character being equivalent to the re-encoded character, use the `UTF8View::validate()`
|
|
// method on the view prior to using its iterator.
|
|
size_t underlying_code_point_length_in_bytes() const;
|
|
ReadonlyBytes underlying_code_point_bytes() const;
|
|
bool done() const { return m_length == 0; }
|
|
|
|
private:
|
|
Utf8CodePointIterator(u8 const* ptr, size_t length)
|
|
: m_ptr(ptr)
|
|
, m_length(length)
|
|
{
|
|
}
|
|
|
|
u8 const* m_ptr { nullptr };
|
|
size_t m_length { 0 };
|
|
};
|
|
|
|
class Utf8View {
|
|
public:
|
|
using Iterator = Utf8CodePointIterator;
|
|
|
|
Utf8View() = default;
|
|
|
|
explicit constexpr Utf8View(StringView string)
|
|
: m_string(string)
|
|
{
|
|
}
|
|
|
|
#ifndef KERNEL
|
|
explicit Utf8View(DeprecatedString& string)
|
|
: m_string(string.view())
|
|
{
|
|
}
|
|
|
|
explicit Utf8View(DeprecatedString&&) = delete;
|
|
#endif
|
|
|
|
~Utf8View() = default;
|
|
|
|
StringView as_string() const { return m_string; }
|
|
|
|
Utf8CodePointIterator begin() const { return { begin_ptr(), m_string.length() }; }
|
|
Utf8CodePointIterator end() const { return { end_ptr(), 0 }; }
|
|
Utf8CodePointIterator iterator_at_byte_offset(size_t) const;
|
|
|
|
Utf8CodePointIterator iterator_at_byte_offset_without_validation(size_t) const;
|
|
|
|
unsigned char const* bytes() const { return begin_ptr(); }
|
|
size_t byte_length() const { return m_string.length(); }
|
|
size_t byte_offset_of(Utf8CodePointIterator const&) const;
|
|
size_t byte_offset_of(size_t code_point_offset) const;
|
|
|
|
Utf8View substring_view(size_t byte_offset, size_t byte_length) const { return Utf8View { m_string.substring_view(byte_offset, byte_length) }; }
|
|
Utf8View substring_view(size_t byte_offset) const { return substring_view(byte_offset, byte_length() - byte_offset); }
|
|
Utf8View unicode_substring_view(size_t code_point_offset, size_t code_point_length) const;
|
|
Utf8View unicode_substring_view(size_t code_point_offset) const { return unicode_substring_view(code_point_offset, length() - code_point_offset); }
|
|
|
|
bool is_empty() const { return m_string.is_empty(); }
|
|
bool is_null() const { return m_string.is_null(); }
|
|
bool starts_with(Utf8View const&) const;
|
|
bool contains(u32) const;
|
|
|
|
Utf8View trim(Utf8View const& characters, TrimMode mode = TrimMode::Both) const;
|
|
|
|
size_t iterator_offset(Utf8CodePointIterator const& it) const
|
|
{
|
|
return byte_offset_of(it);
|
|
}
|
|
|
|
size_t length() const
|
|
{
|
|
if (!m_have_length) {
|
|
m_length = calculate_length();
|
|
m_have_length = true;
|
|
}
|
|
return m_length;
|
|
}
|
|
|
|
constexpr bool validate() const
|
|
{
|
|
size_t valid_bytes = 0;
|
|
return validate(valid_bytes);
|
|
}
|
|
|
|
constexpr bool validate(size_t& valid_bytes) const
|
|
{
|
|
valid_bytes = 0;
|
|
|
|
for (auto it = m_string.begin(); it != m_string.end(); ++it) {
|
|
auto [byte_length, code_point, is_valid] = decode_leading_byte(static_cast<u8>(*it));
|
|
if (!is_valid)
|
|
return false;
|
|
|
|
for (size_t i = 1; i < byte_length; ++i) {
|
|
if (++it == m_string.end())
|
|
return false;
|
|
|
|
auto [code_point_bits, is_valid] = decode_continuation_byte(static_cast<u8>(*it));
|
|
if (!is_valid)
|
|
return false;
|
|
|
|
code_point <<= 6;
|
|
code_point |= code_point_bits;
|
|
}
|
|
|
|
if (!is_valid_code_point(code_point, byte_length))
|
|
return false;
|
|
|
|
valid_bytes += byte_length;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
private:
|
|
friend class Utf8CodePointIterator;
|
|
|
|
u8 const* begin_ptr() const { return reinterpret_cast<u8 const*>(m_string.characters_without_null_termination()); }
|
|
u8 const* end_ptr() const { return begin_ptr() + m_string.length(); }
|
|
size_t calculate_length() const;
|
|
|
|
struct Utf8EncodedByteData {
|
|
size_t byte_length { 0 };
|
|
u8 encoding_bits { 0 };
|
|
u8 encoding_mask { 0 };
|
|
u32 first_code_point { 0 };
|
|
u32 last_code_point { 0 };
|
|
};
|
|
|
|
static constexpr Array<Utf8EncodedByteData, 4> utf8_encoded_byte_data { {
|
|
{ 1, 0b0000'0000, 0b1000'0000, 0x0000, 0x007F },
|
|
{ 2, 0b1100'0000, 0b1110'0000, 0x0080, 0x07FF },
|
|
{ 3, 0b1110'0000, 0b1111'0000, 0x0800, 0xFFFF },
|
|
{ 4, 0b1111'0000, 0b1111'1000, 0x10000, 0x10FFFF },
|
|
} };
|
|
|
|
struct LeadingByte {
|
|
size_t byte_length { 0 };
|
|
u32 code_point_bits { 0 };
|
|
bool is_valid { false };
|
|
};
|
|
|
|
static constexpr LeadingByte decode_leading_byte(u8 byte)
|
|
{
|
|
for (auto const& data : utf8_encoded_byte_data) {
|
|
if ((byte & data.encoding_mask) != data.encoding_bits)
|
|
continue;
|
|
|
|
byte &= ~data.encoding_mask;
|
|
return { data.byte_length, byte, true };
|
|
}
|
|
|
|
return { .is_valid = false };
|
|
}
|
|
|
|
struct ContinuationByte {
|
|
u32 code_point_bits { 0 };
|
|
bool is_valid { false };
|
|
};
|
|
|
|
static constexpr ContinuationByte decode_continuation_byte(u8 byte)
|
|
{
|
|
constexpr u8 continuation_byte_encoding_bits = 0b1000'0000;
|
|
constexpr u8 continuation_byte_encoding_mask = 0b1100'0000;
|
|
|
|
if ((byte & continuation_byte_encoding_mask) == continuation_byte_encoding_bits) {
|
|
byte &= ~continuation_byte_encoding_mask;
|
|
return { byte, true };
|
|
}
|
|
|
|
return { .is_valid = false };
|
|
}
|
|
|
|
static constexpr bool is_valid_code_point(u32 code_point, size_t byte_length)
|
|
{
|
|
for (auto const& data : utf8_encoded_byte_data) {
|
|
if (code_point >= data.first_code_point && code_point <= data.last_code_point)
|
|
return byte_length == data.byte_length;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
StringView m_string;
|
|
mutable size_t m_length { 0 };
|
|
mutable bool m_have_length { false };
|
|
};
|
|
|
|
#ifndef KERNEL
|
|
class DeprecatedStringCodePointIterator {
|
|
public:
|
|
Optional<u32> next()
|
|
{
|
|
if (m_it.done())
|
|
return {};
|
|
auto value = *m_it;
|
|
++m_it;
|
|
return value;
|
|
}
|
|
|
|
[[nodiscard]] Optional<u32> peek() const
|
|
{
|
|
if (m_it.done())
|
|
return {};
|
|
return *m_it;
|
|
}
|
|
|
|
[[nodiscard]] size_t byte_offset() const
|
|
{
|
|
return Utf8View(m_string).byte_offset_of(m_it);
|
|
}
|
|
|
|
DeprecatedStringCodePointIterator(DeprecatedString string)
|
|
: m_string(move(string))
|
|
, m_it(Utf8View(m_string).begin())
|
|
{
|
|
}
|
|
|
|
private:
|
|
DeprecatedString m_string;
|
|
Utf8CodePointIterator m_it;
|
|
};
|
|
#endif
|
|
|
|
template<>
|
|
struct Formatter<Utf8View> : Formatter<StringView> {
|
|
ErrorOr<void> format(FormatBuilder&, Utf8View const&);
|
|
};
|
|
|
|
}
|
|
|
|
#if USING_AK_GLOBALLY
|
|
# ifndef KERNEL
|
|
using AK::DeprecatedStringCodePointIterator;
|
|
# endif
|
|
using AK::Utf8CodePointIterator;
|
|
using AK::Utf8View;
|
|
#endif
|