defmodule Ethers.Types do
@moduledoc "EVM types and compound type definitions"
require Logger
@typedoc """
Ethereum address in its hex format with 0x or in its binary format
## Examples
- `"0xdAC17F958D2ee523a2206206994597C13D831ec7"`
- `<<218, 193, 127, 149, 141, 46, 229, 35, 162, 32, 98, 6, 153, 69, 151, 193, 61, 131, 30, 199>>`
"""
@type t_address :: <<_::336>> | <<_::160>>
@typedoc """
keccak hash in its hex format with 0x
## Examples
- `"0xd4288c8e733eb71a39fe2e8dd4912ce54d8d26d9874f30309b26b4b071260422"`
"""
@type t_hash :: <<_::528>>
@type t_bitsizes :: unquote(8..256//8 |> Enum.reduce(&{:|, [], [&1, &2]}))
@type t_bytesizes :: unquote(1..32 |> Enum.reduce(&{:|, [], [&1, &2]}))
@type t_evm_types ::
{:uint, t_bitsizes()}
| {:int, t_bitsizes()}
| {:bytes, t_bytesizes()}
| :bytes
| :string
| :address
| {:array, t_evm_types()}
| {:array, t_evm_types(), non_neg_integer()}
| {:tuple, [t_evm_types()]}
@valid_bitsize_range 8..256//8
defguardp valid_bitsize(bitsize) when bitsize >= 8 and bitsize <= 256 and rem(bitsize, 8) == 0
defguardp valid_bytesize(bytesize) when bytesize >= 1 and bytesize <= 32
@doc """
Converts EVM data types to typespecs for documentation
"""
def to_elixir_type(:address) do
quote do: Ethers.Types.t_address()
end
def to_elixir_type({:array, sub_type, _element_count}) do
to_elixir_type({:array, sub_type})
end
def to_elixir_type({:array, sub_type}) do
sub_type = to_elixir_type(sub_type)
quote do
[unquote(sub_type)]
end
end
def to_elixir_type({:bytes, size}) when valid_bytesize(size) do
quote do: <<_::unquote(size * 8)>>
end
def to_elixir_type(:bytes) do
quote do: binary()
end
def to_elixir_type(:bool) do
quote do: boolean()
end
def to_elixir_type(:function) do
raise "Function type not supported!"
end
def to_elixir_type({:ufixed, _element_count, _precision}) do
quote do: float()
end
def to_elixir_type({:fixed, _element_count, _precision}) do
quote do: float()
end
def to_elixir_type({:int, _}) do
quote do: integer
end
def to_elixir_type(:string) do
quote do: String.t()
end
def to_elixir_type({:tuple, sub_types}) do
sub_types = Enum.map(sub_types, &to_elixir_type/1)
quote do: {unquote_splicing(sub_types)}
end
def to_elixir_type({:uint, _}) do
quote do: non_neg_integer
end
def to_elixir_type(unknown) do
Logger.warning("Unknown type #{inspect(unknown)}")
quote do: term
end
@doc """
Returns the maximum possible value in the given type if supported.
## Examples
iex> Ethers.Types.max({:uint, 8})
255
iex> Ethers.Types.max({:int, 8})
127
iex> Ethers.Types.max({:uint, 16})
65535
iex> Ethers.Types.max({:int, 16})
32767
iex> Ethers.Types.max({:uint, 128})
340282366920938463463374607431768211455
iex> Ethers.Types.max({:int, 128})
170141183460469231731687303715884105727
"""
def max(type)
Enum.each(@valid_bitsize_range, fn bitsize ->
{int_res, uint_res} =
Enum.reduce(1..bitsize, {1, 1}, fn _bsize, {_, acc} -> {acc, 2 * acc} end)
def max({:uint, unquote(bitsize)}) do
unquote(uint_res - 1)
end
def max({:int, unquote(bitsize)}) do
unquote(int_res - 1)
end
end)
@doc """
Returns the minimum possible value in the given type if supported.
## Examples
iex> Ethers.Types.min({:uint, 8})
0
iex> Ethers.Types.min({:int, 8})
-128
iex> Ethers.Types.min({:uint, 16})
0
iex> Ethers.Types.min({:int, 16})
-32768
iex> Ethers.Types.min({:int, 24})
-8388608
iex> Ethers.Types.min({:int, 128})
-170141183460469231731687303715884105728
"""
def min(type)
def min({:uint, bitsize}) when valid_bitsize(bitsize), do: 0
Enum.each(@valid_bitsize_range, fn bitsize ->
int_res = Enum.reduce(1..(bitsize - 1), 1, fn _bsize, acc -> 2 * acc end)
def min({:int, unquote(bitsize)}) do
unquote(-int_res)
end
end)
@doc """
Returns the default value in the given type if supported.
## Examples
iex> Ethers.Types.default(:address)
"0x0000000000000000000000000000000000000000"
iex> Ethers.Types.default({:int, 32})
0
iex> Ethers.Types.default({:uint, 8})
0
iex> Ethers.Types.default({:int, 128})
0
iex> Ethers.Types.default(:string)
""
iex> Ethers.Types.default(:bytes)
""
iex> Ethers.Types.default({:bytes, 8})
<<0, 0, 0, 0, 0, 0, 0, 0>>
"""
def default({type, _}) when type in [:int, :uint], do: 0
def default(:address), do: "0x0000000000000000000000000000000000000000"
def default(type) when type in [:string, :bytes], do: ""
def default({:bytes, size}) when valid_bytesize(size), do: <<0::size*8>>
@doc """
Checks if a given data matches a given solidity type
## Examples
iex> Ethers.Types.matches_type?(false, :bool)
true
iex> Ethers.Types.matches_type?(200, {:uint, 8})
true
iex> Ethers.Types.matches_type?(400, {:uint, 8})
false
iex> Ethers.Types.matches_type?("0xdAC17F958D2ee523a2206206994597C13D831ec7", :address)
true
"""
@spec matches_type?(term(), t_evm_types()) :: boolean()
def matches_type?(value, type)
def matches_type?(value, {:uint, _bsize} = type),
do: is_integer(value) and value >= 0 and value <= max(type)
def matches_type?(value, {:int, _bsize} = type),
do: is_integer(value) and value >= min(type) and value <= max(type)
def matches_type?(value, :address) when is_binary(value) do
byte_size(value) == 20 or (byte_size(value) == 42 and String.starts_with?(value, "0x"))
end
def matches_type?(_value, :address), do: false
def matches_type?(value, :string), do: is_binary(value) and String.valid?(value)
def matches_type?(value, :bytes), do: is_binary(value)
def matches_type?(value, {:bytes, size}) when valid_bytesize(size),
do: is_binary(value) && byte_size(value) == size
def matches_type?(_value, {:bytes, size}),
do: raise(ArgumentError, "Invalid size: #{inspect(size)} (must be 1 <= size <= 32)")
def matches_type?(value, :bool), do: is_boolean(value)
def matches_type?(values, {:array, sub_type, element_count}) do
matches_type?(values, {:array, sub_type}) and Enum.count(values) == element_count
end
def matches_type?(values, {:array, sub_type}) do
is_list(values) and Enum.all?(values, &matches_type?(&1, sub_type))
end
def matches_type?(values, {:tuple, sub_types}) do
if is_tuple(values) and tuple_size(values) == Enum.count(sub_types) do
Enum.zip(sub_types, Tuple.to_list(values))
|> Enum.all?(fn {type, value} -> matches_type?(value, type) end)
else
false
end
end
@doc """
Validates and creates typed values to use with functions or events.
Typed values are useful when there are multiple overloads of same function or event and you need
to specify one of them to be used.
Also raises with ArgumentError in case value does not match the given type.
## Examples
iex> Ethers.Types.typed({:uint, 256}, 5)
{:typed, {:uint, 256}, 5}
iex> Ethers.Types.typed(:bytes, <<0, 1, 2>>)
{:typed, :bytes, <<0, 1, 2>>}
"""
@spec typed(term(), t_evm_types() | nil) :: {:typed, term(), term()} | no_return()
def typed(type, nil), do: {:typed, type, nil}
def typed(type, value) do
if matches_type?(value, type) do
{:typed, type, value}
else
raise ArgumentError, "Value #{inspect(value)} does not match type #{inspect(type)}"
end
end
end
