ladybird/AK/Utf8View.h

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/*
* Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#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;
ssize_t operator-(const Utf8CodepointIterator& other) const
{
return m_ptr - other.m_ptr;
}
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size_t code_point_length_in_bytes() const;
bool done() const { return m_length == 0; }
private:
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Utf8CodepointIterator(const unsigned char*, size_t);
const unsigned char* m_ptr { nullptr };
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size_t m_length;
};
class Utf8View {
public:
using Iterator = Utf8CodepointIterator;
Utf8View() = default;
explicit Utf8View(const String&);
explicit Utf8View(const StringView&);
explicit Utf8View(const char*);
~Utf8View() = default;
const StringView& as_string() const { return m_string; }
Utf8CodepointIterator begin() const;
Utf8CodepointIterator end() const;
const unsigned char* bytes() const { return begin_ptr(); }
int byte_length() const { return m_string.length(); }
size_t byte_offset_of(const Utf8CodepointIterator&) const;
Utf8View substring_view(int byte_offset, int byte_length) const;
bool is_empty() const { return m_string.is_empty(); }
bool starts_with(const Utf8View&) 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;