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/*
* 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/String.h>
#include <AK/StringView.h>
#include <AK/Types.h>
namespace AK {
class Utf8View;
class Utf8CodePointIterator {
friend class Utf8View;
public:
Utf8CodePointIterator() = default;
~Utf8CodePointIterator() = default;
bool operator==(const Utf8CodePointIterator&) const;
bool operator!=(const Utf8CodePointIterator&) const;
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-(const Utf8CodePointIterator& other) const
{
return m_ptr - other.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(const unsigned char*, size_t);
const unsigned char* m_ptr { nullptr };
size_t m_length;
};
class Utf8View {
public:
using Iterator = Utf8CodePointIterator;
Utf8View() = default;
explicit Utf8View(String& string)
: m_string(string.view())
{
}
explicit Utf8View(StringView string)
: m_string(string)
{
}
~Utf8View() = default;
explicit Utf8View(String&&) = delete;
const StringView& as_string() const { return m_string; }
Utf8CodePointIterator begin() const;
Utf8CodePointIterator end() const;
Utf8CodePointIterator iterator_at_byte_offset(size_t) const;
const unsigned char* bytes() const { return begin_ptr(); }
size_t byte_length() const { return m_string.length(); }
size_t byte_offset_of(const Utf8CodePointIterator&) const;
size_t byte_offset_of(size_t code_point_offset) const;
Utf8View substring_view(size_t byte_offset, size_t byte_length) const;
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(const Utf8View&) const;
bool contains(u32) const;
Utf8View trim(const Utf8View& characters, TrimMode mode = TrimMode::Both) const;
size_t iterator_offset(const Utf8CodePointIterator& it) const
{
return byte_offset_of(it);
}
bool validate(size_t& valid_bytes) const;
bool validate() const
{
size_t valid_bytes;
return validate(valid_bytes);
}
size_t length() const
{
if (!m_have_length) {
m_length = calculate_length();
m_have_length = true;
}
return m_length;
}
private:
const unsigned char* begin_ptr() const;
const unsigned char* end_ptr() const;
size_t calculate_length() const;
StringView m_string;
mutable size_t m_length { 0 };
mutable bool m_have_length { false };
};
}
using AK::Utf8CodePointIterator;
using AK::Utf8View;
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