bitty

-module(bitty).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/bitty.gleam").
-export([make_parser/1, run_parser/2, success/1, fail/1, from_result/1, map/2, then/2, one_of/1, attempt/1, cut/1, label/2, context/2, many/1, many1/1, repeat/2, optional/1, location/0, align/0, 'end'/0, advance_bits/3, read_uint/4, stop_expected/2, within_bytes/2, read_n_bytes/2, effective_byte_offset/1, within_bytes_partial/2, run/2, run_partial/2, run_with_location/2]).
-export_type([location/0, bitty_error/0, parser/1, state/0, step/1]).

-if(?OTP_RELEASE >= 27).
-define(MODULEDOC(Str), -moduledoc(Str)).
-define(DOC(Str), -doc(Str)).
-else.
-define(MODULEDOC(Str), -compile([])).
-define(DOC(Str), -compile([])).
-endif.

?MODULEDOC(
    " Zero-copy binary parser combinators for Gleam, targeting both BEAM and\n"
    " JavaScript. Build parsers by composing primitives from `bitty/bytes`,\n"
    " `bitty/bits`, and `bitty/num` with the combinators in this module.\n"
    " Parsers are designed for Gleam's `use` syntax.\n"
).

-type location() :: {location, integer(), integer()}.

-type bitty_error() :: {bitty_error,
        location(),
        list(binary()),
        list(binary()),
        gleam@option:option(binary())}.

-opaque parser(OZP) :: {parser, fun((state()) -> step(OZP))}.

-type state() :: {state, bitstring(), integer(), integer(), boolean()}.

-type step(OZQ) :: {continue, OZQ, state(), boolean()} |
    {stop, bitty_error(), boolean(), boolean()}.

-file("src/bitty.gleam", 51).
?DOC(false).
-spec make_parser(fun((state()) -> step(OZR))) -> parser(OZR).
make_parser(F) ->
    {parser, F}.

-file("src/bitty.gleam", 56).
?DOC(false).
-spec run_parser(parser(OZU), state()) -> step(OZU).
run_parser(Parser, State) ->
    (erlang:element(2, Parser))(State).

-file("src/bitty.gleam", 62).
?DOC(
    " Create a parser that always succeeds with the given value without\n"
    " consuming any input.\n"
).
-spec success(OZX) -> parser(OZX).
success(Value) ->
    {parser, fun(State) -> {continue, Value, State, false} end}.

-file("src/bitty.gleam", 68).
?DOC(
    " Create a parser that always fails with the given message without\n"
    " consuming any input.\n"
).
-spec fail(binary()) -> parser(any()).
fail(Message) ->
    {parser,
        fun(State) ->
            {stop,
                {bitty_error,
                    {location,
                        erlang:element(3, State),
                        erlang:element(4, State)},
                    [],
                    [],
                    {some, Message}},
                false,
                erlang:element(5, State)}
        end}.

-file("src/bitty.gleam", 87).
?DOC(
    " Convert a `Result(a, e)` into a parser: `Ok(value)` succeeds with the\n"
    " value, `Error(e)` fails with the inspected error as the message.\n"
    " Useful for lifting fallible conversions (e.g. `bit_array.to_string`)\n"
    " into a parser pipeline with `use` syntax.\n"
).
-spec from_result({ok, PAB} | {error, any()}) -> parser(PAB).
from_result(Result) ->
    case Result of
        {ok, Value} ->
            success(Value);

        {error, E} ->
            fail(gleam@string:inspect(E))
    end.

-file("src/bitty.gleam", 154).
?DOC(" Transform the result of a parser by applying `f` to the parsed value.\n").
-spec map(parser(PAW), fun((PAW) -> PAY)) -> parser(PAY).
map(Parser, F) ->
    {parser, fun(State) -> case (erlang:element(2, Parser))(State) of
                {continue, Value, State1, Consumed} ->
                    {continue, F(Value), State1, Consumed};

                {stop, Error, Consumed@1, Committed} ->
                    {stop, Error, Consumed@1, Committed}
            end end}.

-file("src/bitty.gleam", 171).
?DOC(
    " Sequence two parsers: run `parser`, then pass its result to `next` to\n"
    " get the second parser. Designed for Gleam's `use` syntax:\n"
    "\n"
    " ```gleam\n"
    " use length <- bitty.then(num.u8())\n"
    " use data <- bitty.then(bytes.take(length))\n"
    " bitty.success(data)\n"
    " ```\n"
).
-spec then(parser(PBA), fun((PBA) -> parser(PBC))) -> parser(PBC).
then(Parser, Next) ->
    {parser, fun(State) -> case (erlang:element(2, Parser))(State) of
                {continue, Value, State1, Consumed1} ->
                    case (erlang:element(2, (Next(Value))))(State1) of
                        {continue, Value2, State2, Consumed2} ->
                            {continue,
                                Value2,
                                State2,
                                Consumed1 orelse Consumed2};

                        {stop, Error, Consumed2@1, Committed2} ->
                            {stop,
                                Error,
                                Consumed1 orelse Consumed2@1,
                                Committed2 orelse erlang:element(5, State1)}
                    end;

                {stop, Error@1, Consumed, Committed} ->
                    {stop, Error@1, Consumed, Committed}
            end end}.

-file("src/bitty.gleam", 232).
-spec merge_errors(bitty_error(), bitty_error()) -> bitty_error().
merge_errors(E1, E2) ->
    Loc1 = (erlang:element(2, erlang:element(2, E1)) * 8) + erlang:element(
        3,
        erlang:element(2, E1)
    ),
    Loc2 = (erlang:element(2, erlang:element(2, E2)) * 8) + erlang:element(
        3,
        erlang:element(2, E2)
    ),
    case gleam@int:compare(Loc1, Loc2) of
        gt ->
            E1;

        lt ->
            E2;

        eq ->
            {bitty_error,
                erlang:element(2, E1),
                lists:append(erlang:element(3, E1), erlang:element(3, E2)),
                erlang:element(4, E1),
                erlang:element(5, E1)}
    end.

-file("src/bitty.gleam", 213).
-spec try_parsers(list(parser(PBJ)), state(), bitty_error()) -> step(PBJ).
try_parsers(Parsers, State, Last_error) ->
    case Parsers of
        [] ->
            {stop, Last_error, false, false};

        [Parser | Rest] ->
            case (erlang:element(2, Parser))(State) of
                {continue, _, _, _} = Success ->
                    Success;

                {stop, Error, Consumed, Committed} ->
                    case Consumed orelse Committed of
                        true ->
                            {stop, Error, Consumed, Committed};

                        false ->
                            try_parsers(
                                Rest,
                                State,
                                merge_errors(Last_error, Error)
                            )
                    end
            end
    end.

-file("src/bitty.gleam", 198).
?DOC(
    " Try each parser in order, returning the first success. A parser that\n"
    " consumes input before failing will **not** backtrack — wrap alternatives\n"
    " in `attempt` if backtracking is needed. Errors from non-consuming\n"
    " failures at the same position are merged.\n"
    "\n"
    " ```gleam\n"
    " let parser = bitty.one_of([\n"
    "   bitty.attempt(bytes.tag(<<0x01>>) |> bitty.map(fn(_) { \"one\" })),\n"
    "   bytes.tag(<<0x02>>) |> bitty.map(fn(_) { \"two\" }),\n"
    " ])\n"
    " let assert Ok(\"two\") = bitty.run(parser, on: <<0x02>>)\n"
    " ```\n"
).
-spec one_of(list(parser(PBF))) -> parser(PBF).
one_of(Parsers) ->
    {parser,
        fun(State) ->
            try_parsers(
                Parsers,
                State,
                {bitty_error,
                    {location,
                        erlang:element(3, State),
                        erlang:element(4, State)},
                    [],
                    [],
                    none}
            )
        end}.

-file("src/bitty.gleam", 254).
?DOC(
    " Wrap a parser to allow backtracking on failure. If the inner parser\n"
    " fails after consuming input, `attempt` resets the consumed flag so\n"
    " that `one_of` can try the next alternative.\n"
    "\n"
    " ```gleam\n"
    " let parser = bitty.one_of([\n"
    "   bitty.attempt(bytes.tag(<<0xCA, 0xFE>>)),\n"
    "   bytes.tag(<<0xCA, 0x11>>),\n"
    " ])\n"
    " let assert Ok(Nil) = bitty.run(parser, on: <<0xCA, 0x11>>)\n"
    " ```\n"
).
-spec attempt(parser(PBN)) -> parser(PBN).
attempt(Parser) ->
    {parser, fun(State) -> case (erlang:element(2, Parser))(State) of
                {continue, _, _, _} = Success ->
                    Success;

                {stop, Error, _, Committed} ->
                    {stop, Error, false, Committed}
            end end}.

-file("src/bitty.gleam", 272).
?DOC(
    " Commit to the current parse path on success. After `cut`, a later\n"
    " failure will not backtrack past this point, producing better error\n"
    " messages. Typically used after matching a tag or discriminator.\n"
    "\n"
    " ```gleam\n"
    " use _ <- bitty.then(bitty.cut(bytes.tag(<<0x01>>)))\n"
    " use value <- bitty.then(num.u8())\n"
    " bitty.success(value)\n"
    " ```\n"
).
-spec cut(parser(PBQ)) -> parser(PBQ).
cut(Parser) ->
    {parser, fun(State) -> case (erlang:element(2, Parser))(State) of
                {continue, Value, State1, Consumed} ->
                    {continue,
                        Value,
                        {state,
                            erlang:element(2, State1),
                            erlang:element(3, State1),
                            erlang:element(4, State1),
                            true},
                        Consumed};

                {stop, Error, Consumed@1, Committed} ->
                    {stop, Error, Consumed@1, Committed}
            end end}.

-file("src/bitty.gleam", 290).
?DOC(
    " Replace the `expected` list in a parse error with `name`.\n"
    " Useful for giving user-friendly names to complex parsers.\n"
    "\n"
    " ```gleam\n"
    " let parser = num.u8() |> bitty.label(named: \"message type\")\n"
    " let assert Error(e) = bitty.run(parser, on: <<>>)\n"
    " assert e.expected == [\"message type\"]\n"
    " ```\n"
).
-spec label(parser(PBT), binary()) -> parser(PBT).
label(Parser, Name) ->
    {parser, fun(State) -> case (erlang:element(2, Parser))(State) of
                {continue, _, _, _} = Success ->
                    Success;

                {stop, Error, Consumed, Committed} ->
                    {stop,
                        {bitty_error,
                            erlang:element(2, Error),
                            [Name],
                            erlang:element(4, Error),
                            erlang:element(5, Error)},
                        Consumed,
                        Committed}
            end end}.

-file("src/bitty.gleam", 308).
?DOC(
    " Push `name` onto the error context stack on failure, creating a\n"
    " breadcrumb trail (e.g. `[\"TLS record\", \"handshake\", \"certificate\"]`).\n"
    "\n"
    " ```gleam\n"
    " let parser = num.u8() |> bitty.context(in: \"header\")\n"
    " let assert Error(e) = bitty.run(parser, on: <<>>)\n"
    " assert e.context == [\"header\"]\n"
    " ```\n"
).
-spec context(parser(PBW), binary()) -> parser(PBW).
context(Parser, Name) ->
    {parser, fun(State) -> case (erlang:element(2, Parser))(State) of
                {continue, _, _, _} = Success ->
                    Success;

                {stop, Error, Consumed, Committed} ->
                    {stop,
                        {bitty_error,
                            erlang:element(2, Error),
                            erlang:element(3, Error),
                            [Name | erlang:element(4, Error)],
                            erlang:element(5, Error)},
                        Consumed,
                        Committed}
            end end}.

-file("src/bitty.gleam", 336).
-spec many_loop(parser(PCD), state(), list(PCD), boolean()) -> step(list(PCD)).
many_loop(Parser, State, Acc, Any_consumed) ->
    case (erlang:element(2, Parser))(
        {state,
            erlang:element(2, State),
            erlang:element(3, State),
            erlang:element(4, State),
            false}
    ) of
        {continue, Value, State1, true} ->
            many_loop(
                Parser,
                {state,
                    erlang:element(2, State1),
                    erlang:element(3, State1),
                    erlang:element(4, State1),
                    erlang:element(5, State1) orelse erlang:element(5, State)},
                [Value | Acc],
                true
            );

        {continue, _, _, false} ->
            {stop,
                {bitty_error,
                    {location,
                        erlang:element(3, State),
                        erlang:element(4, State)},
                    [<<"consuming parser in many"/utf8>>],
                    [],
                    none},
                Any_consumed,
                erlang:element(5, State)};

        {stop, _, false, false} ->
            {continue, lists:reverse(Acc), State, Any_consumed};

        {stop, Error, Consumed, Committed} ->
            {stop,
                Error,
                Any_consumed orelse Consumed,
                Committed orelse erlang:element(5, State)}
    end.

-file("src/bitty.gleam", 332).
?DOC(
    " Repeat a parser zero or more times, collecting results into a list.\n"
    " The inner parser **must** consume input on each iteration; a\n"
    " non-consuming parser causes an immediate error to prevent infinite loops.\n"
    " Stops when the parser fails without consuming input.\n"
    "\n"
    " ```gleam\n"
    " let assert Ok(values) =\n"
    "   bitty.run(bitty.many(num.u8()), on: <<1, 2, 3>>)\n"
    " assert values == [1, 2, 3]\n"
    " ```\n"
).
-spec many(parser(PBZ)) -> parser(list(PBZ)).
many(Parser) ->
    {parser, fun(State) -> many_loop(Parser, State, [], false) end}.

-file("src/bitty.gleam", 369).
?DOC(" Like `many`, but requires at least one successful match.\n").
-spec many1(parser(PCI)) -> parser(list(PCI)).
many1(Parser) ->
    _pipe = Parser,
    then(_pipe, fun(First) -> _pipe@1 = many(Parser),
            map(_pipe@1, fun(Rest) -> [First | Rest] end) end).

-file("src/bitty.gleam", 379).
-spec repeat_loop(parser(PCQ), state(), list(PCQ), integer(), boolean()) -> step(list(PCQ)).
repeat_loop(Parser, State, Acc, Remaining, Any_consumed) ->
    case Remaining =< 0 of
        true ->
            {continue, lists:reverse(Acc), State, Any_consumed};

        false ->
            case (erlang:element(2, Parser))(State) of
                {continue, Value, State1, Consumed} ->
                    repeat_loop(
                        Parser,
                        State1,
                        [Value | Acc],
                        Remaining - 1,
                        Any_consumed orelse Consumed
                    );

                {stop, Error, Consumed@1, Committed} ->
                    {stop, Error, Any_consumed orelse Consumed@1, Committed}
            end
    end.

-file("src/bitty.gleam", 375).
?DOC(" Run a parser exactly `count` times, collecting results into a list.\n").
-spec repeat(parser(PCM), integer()) -> parser(list(PCM)).
repeat(Parser, Count) ->
    {parser, fun(State) -> repeat_loop(Parser, State, [], Count, false) end}.

-file("src/bitty.gleam", 406).
?DOC(
    " Try a parser, returning `Some(value)` on success or `None` if it fails\n"
    " without consuming input. A consuming failure still propagates.\n"
).
-spec optional(parser(PCV)) -> parser(gleam@option:option(PCV)).
optional(Parser) ->
    {parser, fun(State) -> case (erlang:element(2, Parser))(State) of
                {continue, Value, State1, Consumed} ->
                    {continue, {some, Value}, State1, Consumed};

                {stop, _, false, false} ->
                    {continue, none, State, false};

                {stop, Error, Consumed@1, Committed} ->
                    {stop, Error, Consumed@1, Committed}
            end end}.

-file("src/bitty.gleam", 418).
?DOC(" Return the current `Location` in the input without consuming anything.\n").
-spec location() -> parser(location()).
location() ->
    {parser,
        fun(State) ->
            {continue,
                {location, erlang:element(3, State), erlang:element(4, State)},
                State,
                false}
        end}.

-file("src/bitty.gleam", 431).
?DOC(
    " Skip remaining bits in the current byte to reach the next byte boundary.\n"
    " If already aligned, this is a no-op. Use after bit-level parsing to\n"
    " resume byte-aligned operations.\n"
).
-spec align() -> parser(nil).
align() ->
    {parser, fun(State) -> case erlang:element(4, State) =:= 0 of
                true ->
                    {continue, nil, State, false};

                false ->
                    {continue,
                        nil,
                        {state,
                            erlang:element(2, State),
                            erlang:element(3, State) + 1,
                            0,
                            erlang:element(5, State)},
                        true}
            end end}.

-file("src/bitty.gleam", 447).
?DOC(
    " Succeed only if all input has been consumed. Fails with\n"
    " `\"end of input\"` expected if bytes remain.\n"
).
-spec 'end'() -> parser(nil).
'end'() ->
    {parser,
        fun(State) ->
            Remaining = erlang:byte_size(erlang:element(2, State)) - erlang:element(
                3,
                State
            ),
            case (Remaining =:= 0) andalso (erlang:element(4, State) =:= 0) of
                true ->
                    {continue, nil, State, false};

                false ->
                    {stop,
                        {bitty_error,
                            {location,
                                erlang:element(3, State),
                                erlang:element(4, State)},
                            [<<"end of input"/utf8>>],
                            [],
                            none},
                        false,
                        erlang:element(5, State)}
            end
        end}.

-file("src/bitty.gleam", 527).
-spec within_bytes_check(state(), integer(), PDO, state()) -> step(PDO).
within_bytes_check(State, Byte_len, Value, Inner_end) ->
    case (erlang:element(3, Inner_end) =:= Byte_len) andalso (erlang:element(
        4,
        Inner_end
    )
    =:= 0) of
        true ->
            {continue,
                Value,
                {state,
                    erlang:element(2, State),
                    erlang:element(3, State) + Byte_len,
                    erlang:element(4, State),
                    erlang:element(5, State)},
                Byte_len > 0};

        false ->
            {stop,
                {bitty_error,
                    {location,
                        erlang:element(3, State) + erlang:element(3, Inner_end),
                        erlang:element(4, Inner_end)},
                    [<<<<"complete consumption of "/utf8,
                                (erlang:integer_to_binary(Byte_len))/binary>>/binary,
                            "-byte window"/utf8>>],
                    [],
                    none},
                true,
                erlang:element(5, State)}
    end.

-file("src/bitty.gleam", 583).
-spec within_bytes_stop(state(), bitty_error(), boolean(), boolean()) -> step(any()).
within_bytes_stop(State, Error, Consumed, Committed) ->
    {stop,
        {bitty_error,
            {location,
                erlang:element(3, State) + erlang:element(
                    2,
                    erlang:element(2, Error)
                ),
                erlang:element(3, erlang:element(2, Error))},
            erlang:element(3, Error),
            erlang:element(4, Error),
            erlang:element(5, Error)},
        Consumed,
        Committed orelse erlang:element(5, State)}.

-file("src/bitty.gleam", 675).
?DOC(false).
-spec advance_bits(integer(), integer(), integer()) -> {integer(), integer()}.
advance_bits(Byte_offset, Bit_offset, Count) ->
    Total_bits = Bit_offset + Count,
    {Byte_offset + (Total_bits div 8), Total_bits rem 8}.

-file("src/bitty.gleam", 634).
?DOC(false).
-spec read_uint(state(), integer(), integer(), boolean()) -> step(integer()).
read_uint(State, Remaining, Acc, Consumed) ->
    case Remaining =< 0 of
        true ->
            {continue, Acc, State, Consumed};

        false ->
            case gleam_stdlib:bit_array_slice(
                erlang:element(2, State),
                erlang:element(3, State),
                1
            ) of
                {ok, <<Byte>>} ->
                    Available = 8 - erlang:element(4, State),
                    To_read = gleam@int:min(Available, Remaining),
                    Shift = Available - To_read,
                    Mask = erlang:'bsl'(1, To_read) - 1,
                    Bits_val = erlang:'band'(erlang:'bsr'(Byte, Shift), Mask),
                    New_acc = erlang:'bor'(erlang:'bsl'(Acc, To_read), Bits_val),
                    {New_byte, New_bit} = advance_bits(
                        erlang:element(3, State),
                        erlang:element(4, State),
                        To_read
                    ),
                    New_state = {state,
                        erlang:element(2, State),
                        New_byte,
                        New_bit,
                        erlang:element(5, State)},
                    read_uint(New_state, Remaining - To_read, New_acc, Consumed);

                _ ->
                    {stop,
                        {bitty_error,
                            {location,
                                erlang:element(3, State),
                                erlang:element(4, State)},
                            [<<(erlang:integer_to_binary(Remaining))/binary,
                                    " more bits"/utf8>>],
                            [],
                            none},
                        Consumed,
                        erlang:element(5, State)}
            end
    end.

-file("src/bitty.gleam", 709).
-spec read_n_bytes_unaligned(state(), integer(), bitstring(), boolean()) -> step(bitstring()).
read_n_bytes_unaligned(State, Remaining, Acc, Consumed) ->
    case Remaining =< 0 of
        true ->
            {continue, Acc, State, Consumed};

        false ->
            case read_uint(State, 8, 0, Consumed) of
                {continue, Byte_val, New_state, _} ->
                    read_n_bytes_unaligned(
                        New_state,
                        Remaining - 1,
                        <<Acc/bitstring, Byte_val>>,
                        Consumed
                    );

                {stop, Error, Consumed2, Committed} ->
                    {stop, Error, Consumed2, Committed}
            end
    end.

-file("src/bitty.gleam", 732).
?DOC(false).
-spec stop_expected(state(), binary()) -> step(any()).
stop_expected(State, Expected) ->
    {stop,
        {bitty_error,
            {location, erlang:element(3, State), erlang:element(4, State)},
            [Expected],
            [],
            none},
        false,
        erlang:element(5, State)}.

-file("src/bitty.gleam", 489).
-spec within_bytes_setup(
    state(),
    integer(),
    parser(PDF),
    fun((state(), bitstring(), step(PDF)) -> step(PDI))
) -> step(PDI).
within_bytes_setup(State, Byte_len, Inner, On_window) ->
    Remaining = erlang:byte_size(erlang:element(2, State)) - erlang:element(
        3,
        State
    ),
    case Remaining < Byte_len of
        true ->
            stop_expected(
                State,
                <<<<"at least "/utf8,
                        (erlang:integer_to_binary(Byte_len))/binary>>/binary,
                    " bytes"/utf8>>
            );

        false ->
            case gleam_stdlib:bit_array_slice(
                erlang:element(2, State),
                erlang:element(3, State),
                Byte_len
            ) of
                {ok, Window} ->
                    Inner_state = {state, Window, 0, 0, false},
                    On_window(
                        State,
                        Window,
                        (erlang:element(2, Inner))(Inner_state)
                    );

                _ ->
                    stop_expected(State, <<"valid slice"/utf8>>)
            end
    end.

-file("src/bitty.gleam", 516).
-spec within_bytes_run(state(), integer(), parser(PDL)) -> step(PDL).
within_bytes_run(State, Byte_len, Inner) ->
    within_bytes_setup(
        State,
        Byte_len,
        Inner,
        fun(St, _, Result) -> case Result of
                {continue, Value, Inner_end, _} ->
                    within_bytes_check(St, Byte_len, Value, Inner_end);

                {stop, Error, Consumed, Committed} ->
                    within_bytes_stop(St, Error, Consumed, Committed)
            end end
    ).

-file("src/bitty.gleam", 476).
?DOC(
    " Run `inner` on a zero-copy window of exactly `byte_len` bytes.\n"
    " The inner parser must consume the entire window or the parse fails.\n"
    " Requires byte alignment.\n"
    "\n"
    " ```gleam\n"
    " use length <- bitty.then(num.u8())\n"
    " use value <- bitty.then(bitty.within_bytes(length, run: bytes.rest()))\n"
    " bitty.success(value)\n"
    " ```\n"
).
-spec within_bytes(integer(), parser(PDC)) -> parser(PDC).
within_bytes(Byte_len, Inner) ->
    {parser,
        fun(State) ->
            gleam@bool:guard(
                Byte_len < 0,
                stop_expected(State, <<"non-negative byte length"/utf8>>),
                fun() -> case erlang:element(4, State) /= 0 of
                        true ->
                            stop_expected(State, <<"byte alignment"/utf8>>);

                        false ->
                            within_bytes_run(State, Byte_len, Inner)
                    end end
            )
        end}.

-file("src/bitty.gleam", 697).
-spec read_n_bytes_aligned(state(), integer()) -> step(bitstring()).
read_n_bytes_aligned(State, Count) ->
    case gleam_stdlib:bit_array_slice(
        erlang:element(2, State),
        erlang:element(3, State),
        Count
    ) of
        {ok, Bytes} ->
            {continue,
                Bytes,
                {state,
                    erlang:element(2, State),
                    erlang:element(3, State) + Count,
                    erlang:element(4, State),
                    erlang:element(5, State)},
                Count > 0};

        _ ->
            stop_expected(
                State,
                <<(erlang:integer_to_binary(Count))/binary, " bytes"/utf8>>
            )
    end.

-file("src/bitty.gleam", 685).
?DOC(false).
-spec read_n_bytes(state(), integer()) -> step(bitstring()).
read_n_bytes(State, Count) ->
    gleam@bool:guard(
        Count < 0,
        stop_expected(State, <<"non-negative byte count"/utf8>>),
        fun() -> case erlang:element(4, State) =:= 0 of
                true ->
                    read_n_bytes_aligned(State, Count);

                false ->
                    read_n_bytes_unaligned(State, Count, <<>>, Count > 0)
            end end
    ).

-file("src/bitty.gleam", 746).
?DOC(false).
-spec effective_byte_offset(state()) -> integer().
effective_byte_offset(State) ->
    case erlang:element(4, State) /= 0 of
        true ->
            erlang:element(3, State) + 1;

        false ->
            erlang:element(3, State)
    end.

-file("src/bitty.gleam", 561).
-spec within_bytes_partial_check(state(), integer(), PDQ, state(), bitstring()) -> step({PDQ,
    bitstring()}).
within_bytes_partial_check(State, Byte_len, Value, Inner_end, Window) ->
    Effective_inner_offset = effective_byte_offset(Inner_end),
    Unconsumed = Byte_len - Effective_inner_offset,
    Leftover = case gleam_stdlib:bit_array_slice(
        Window,
        Effective_inner_offset,
        Unconsumed
    ) of
        {ok, Rest} ->
            Rest;

        _ ->
            <<>>
    end,
    {continue,
        {Value, Leftover},
        {state,
            erlang:element(2, State),
            erlang:element(3, State) + Byte_len,
            erlang:element(4, State),
            erlang:element(5, State)},
        Byte_len > 0}.

-file("src/bitty.gleam", 618).
-spec within_bytes_partial_run(state(), integer(), parser(PDX)) -> step({PDX,
    bitstring()}).
within_bytes_partial_run(State, Byte_len, Inner) ->
    within_bytes_setup(
        State,
        Byte_len,
        Inner,
        fun(St, Window, Result) -> case Result of
                {continue, Value, Inner_end, _} ->
                    within_bytes_partial_check(
                        St,
                        Byte_len,
                        Value,
                        Inner_end,
                        Window
                    );

                {stop, Error, Consumed, Committed} ->
                    within_bytes_stop(St, Error, Consumed, Committed)
            end end
    ).

-file("src/bitty.gleam", 602).
?DOC(
    " Like `within_bytes`, but the inner parser may stop early. Returns the\n"
    " parsed value and any unconsumed bytes from the window as a tuple.\n"
    " Requires byte alignment.\n"
).
-spec within_bytes_partial(integer(), parser(PDU)) -> parser({PDU, bitstring()}).
within_bytes_partial(Byte_len, Inner) ->
    {parser,
        fun(State) ->
            gleam@bool:guard(
                Byte_len < 0,
                stop_expected(State, <<"non-negative byte length"/utf8>>),
                fun() -> case erlang:element(4, State) /= 0 of
                        true ->
                            stop_expected(State, <<"byte alignment"/utf8>>);

                        false ->
                            within_bytes_partial_run(State, Byte_len, Inner)
                    end end
            )
        end}.

-file("src/bitty.gleam", 753).
-spec remaining_slice(state()) -> bitstring().
remaining_slice(State) ->
    Offset = effective_byte_offset(State),
    Remaining = erlang:byte_size(erlang:element(2, State)) - Offset,
    case gleam_stdlib:bit_array_slice(
        erlang:element(2, State),
        Offset,
        Remaining
    ) of
        {ok, Rest} ->
            Rest;

        _ ->
            <<>>
    end.

-file("src/bitty.gleam", 762).
-spec new_state(bitstring()) -> state().
new_state(Input) ->
    {state, Input, 0, 0, false}.

-file("src/bitty.gleam", 145).
-spec do_run(parser(PAS), bitstring()) -> {ok, {PAS, state()}} |
    {error, bitty_error()}.
do_run(Parser, Input) ->
    State = new_state(Input),
    case (erlang:element(2, Parser))(State) of
        {continue, Value, Final_state, _} ->
            {ok, {Value, Final_state}};

        {stop, Error, _, _} ->
            {error, Error}
    end.

-file("src/bitty.gleam", 101).
?DOC(
    " Run a parser on the given input, requiring it to consume all bytes.\n"
    " Returns `Error` if parsing fails or if unconsumed input remains.\n"
    "\n"
    " ```gleam\n"
    " let assert Ok(byte) = bitty.run(num.u8(), on: <<0xFF>>)\n"
    " assert byte == 255\n"
    " ```\n"
).
-spec run(parser(PAG), bitstring()) -> {ok, PAG} | {error, bitty_error()}.
run(Parser, Input) ->
    gleam@result:'try'(
        do_run(Parser, Input),
        fun(_use0) ->
            {Value, Final_state} = _use0,
            Remaining = erlang:byte_size(erlang:element(2, Final_state)) - erlang:element(
                3,
                Final_state
            ),
            case (Remaining =:= 0) andalso (erlang:element(4, Final_state) =:= 0) of
                true ->
                    {ok, Value};

                false ->
                    {error,
                        {bitty_error,
                            {location,
                                erlang:element(3, Final_state),
                                erlang:element(4, Final_state)},
                            [<<"end of input"/utf8>>],
                            [],
                            none}}
            end
        end
    ).

-file("src/bitty.gleam", 126).
?DOC(
    " Run a parser on the given input, returning the parsed value and any\n"
    " unconsumed bytes. Does not require all input to be consumed.\n"
    "\n"
    " ```gleam\n"
    " let assert Ok(#(byte, rest)) =\n"
    "   bitty.run_partial(num.u8(), on: <<0xAA, 0xBB>>)\n"
    " assert byte == 0xAA\n"
    " assert rest == <<0xBB>>\n"
    " ```\n"
).
-spec run_partial(parser(PAK), bitstring()) -> {ok, {PAK, bitstring()}} |
    {error, bitty_error()}.
run_partial(Parser, Input) ->
    gleam@result:'try'(
        do_run(Parser, Input),
        fun(_use0) ->
            {Value, Final_state} = _use0,
            {ok, {Value, remaining_slice(Final_state)}}
        end
    ).

-file("src/bitty.gleam", 136).
?DOC(
    " Like `run_partial`, but also returns the `Location` where the parser\n"
    " stopped. Useful for incremental or streaming parsing.\n"
).
-spec run_with_location(parser(PAO), bitstring()) -> {ok,
        {PAO, location(), bitstring()}} |
    {error, bitty_error()}.
run_with_location(Parser, Input) ->
    gleam@result:'try'(
        do_run(Parser, Input),
        fun(_use0) ->
            {Value, Final_state} = _use0,
            Loc = {location,
                erlang:element(3, Final_state),
                erlang:element(4, Final_state)},
            {ok, {Value, Loc, remaining_slice(Final_state)}}
        end
    ).