serenity/Userland/Libraries/LibTextCodec/Decoder.h

/*
 * Copyright (c) 2020-2021, Andreas Kling <kling@serenityos.org>
 * Copyright (c) 2022, Jelle Raaijmakers <jelle@gmta.nl>
 * Copyright (c) 2023, Sam Atkins <atkinssj@serenityos.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#pragma once

#include <AK/Forward.h>
#include <AK/Function.h>
#include <AK/Optional.h>
#include <AK/String.h>

namespace TextCodec {

class Decoder {
public:
    virtual ErrorOr<void> process(StringView, Function<ErrorOr<void>(u32)> on_code_point) = 0;
    virtual ErrorOr<String> to_utf8(StringView);

protected:
    virtual ~Decoder() = default;
};

class UTF8Decoder final : public Decoder {
public:
    virtual ErrorOr<void> process(StringView, Function<ErrorOr<void>(u32)> on_code_point) override;
    virtual ErrorOr<String> to_utf8(StringView) override;
};

class UTF16BEDecoder final : public Decoder {
public:
    virtual ErrorOr<void> process(StringView, Function<ErrorOr<void>(u32)> on_code_point) override;
    virtual ErrorOr<String> to_utf8(StringView) override;
};

class UTF16LEDecoder final : public Decoder {
public:
    virtual ErrorOr<void> process(StringView, Function<ErrorOr<void>(u32)> on_code_point) override;
    virtual ErrorOr<String> to_utf8(StringView) override;
};

class Latin1Decoder final : public Decoder {
public:
    virtual ErrorOr<void> process(StringView, Function<ErrorOr<void>(u32)> on_code_point) override;
};

class Latin2Decoder final : public Decoder {
public:
    virtual ErrorOr<void> process(StringView, Function<ErrorOr<void>(u32)> on_code_point) override;
};

class HebrewDecoder final : public Decoder {
public:
    virtual ErrorOr<void> process(StringView, Function<ErrorOr<void>(u32)> on_code_point) override;
};

class CyrillicDecoder final : public Decoder {
public:
    virtual ErrorOr<void> process(StringView, Function<ErrorOr<void>(u32)> on_code_point) override;
};

class Koi8RDecoder final : public Decoder {
public:
    virtual ErrorOr<void> process(StringView, Function<ErrorOr<void>(u32)> on_code_point) override;
};

class Latin9Decoder final : public Decoder {
public:
    virtual ErrorOr<void> process(StringView, Function<ErrorOr<void>(u32)> on_code_point) override;
};

class MacRomanDecoder final : public Decoder {
public:
    virtual ErrorOr<void> process(StringView, Function<ErrorOr<void>(u32)> on_code_point) override;
};

class TurkishDecoder final : public Decoder {
public:
    virtual ErrorOr<void> process(StringView, Function<ErrorOr<void>(u32)> on_code_point) override;
};

class XUserDefinedDecoder final : public Decoder {
public:
    virtual ErrorOr<void> process(StringView, Function<ErrorOr<void>(u32)> on_code_point) override;
};

Optional<Decoder&> decoder_for(StringView encoding);
Optional<StringView> get_standardized_encoding(StringView encoding);

// This returns the appropriate Unicode decoder for the sniffed BOM or nothing if there is no appropriate decoder.
Optional<Decoder&> bom_sniff_to_decoder(StringView);

// NOTE: This has an obnoxious name to discourage usage. Only use this if you absolutely must! For example, XHR in LibWeb uses this.
// This will use the given decoder unless there is a byte order mark in the input, in which we will instead use the appropriate Unicode decoder.
ErrorOr<String> convert_input_to_utf8_using_given_decoder_unless_there_is_a_byte_order_mark(Decoder&, StringView);

}