# `EEVM.Storage`
[🔗](https://github.com/mw2000/eevm/blob/main/lib/eevm/storage.ex#L1)

Persistent key-value storage for a single contract account: a mapping from
256-bit slot keys to 256-bit values.

Uninitialized slots return `0`. All values are masked to 256 bits on write.

# `t`

```elixir
@type t() :: %EEVM.Storage{slots: %{required(non_neg_integer()) => non_neg_integer()}}
```

# `load`

```elixir
@spec load(t(), non_neg_integer()) :: non_neg_integer()
```

Loads a value from a storage slot.

Returns 0 for uninitialized slots — the EVM treats all 2^256 slots as
existing with a default value of 0.

## Example

    iex> storage = EEVM.Storage.new()
    iex> EEVM.Storage.load(storage, 42)
    0

# `new`

```elixir
@spec new() :: t()
```

Creates a new empty storage.

# `new`

```elixir
@spec new(%{required(non_neg_integer()) => non_neg_integer()}) :: t()
```

Creates storage pre-loaded with initial slot values.

Useful for testing or simulating contract state.

## Example

    iex> storage = EEVM.Storage.new(%{0 => 42, 1 => 100})
    iex> EEVM.Storage.load(storage, 0)
    42

# `store`

```elixir
@spec store(t(), non_neg_integer(), non_neg_integer()) :: t()
```

Stores a value into a storage slot.

Returns the updated storage. Writing 0 to a slot is valid and keeps the
key in the map (in a production EVM, this could trigger a gas refund).

## Example

    iex> storage = EEVM.Storage.new() |> EEVM.Storage.store(0, 42)
    iex> EEVM.Storage.load(storage, 0)
    42

# `to_map`

```elixir
@spec to_map(t()) :: %{required(non_neg_integer()) => non_neg_integer()}
```

Returns the storage contents as a map for inspection.

---

*Consult [api-reference.md](api-reference.md) for complete listing*