-module(viva_tensor@layout).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/viva_tensor/layout.gleam").
-export_type([tensor_storage/0, tensor_device/0, tensor_dtype/0, tensor_memory_layout/0, tensor_layout/0]).

-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(
    " Tensor layout metadata.\n"
    "\n"
    " A tensor is not just its values. To interpret tensor storage correctly, every\n"
    " backend needs the same small contract: shape, strides, offset, dtype, device,\n"
    " and storage representation.\n"
).

-type tensor_storage() :: dense_storage | strided_storage | native_storage.

-type tensor_device() :: beam_cpu | native_cpu | {cuda_device, integer()}.

-type tensor_dtype() :: float64 |
    float32 |
    float16 |
    b_float16 |
    float8_e4_m3 |
    int8 |
    int4 |
    sparse_float16.

-type tensor_memory_layout() :: row_major |
    column_major |
    strided_layout |
    packed_fp8_layout |
    packed_sparse24_layout.

-type tensor_layout() :: {tensor_layout,
        tensor_storage(),
        tensor_device(),
        tensor_dtype(),
        list(integer()),
        list(integer()),
        integer(),
        integer(),
        integer(),
        boolean()}.