defmodule Ash.Type.Function do
@moduledoc """
Represents a function.
If the type would be dumped to a native format, `:erlang.term_to_binary(term, [:safe])` is used.
Please keep in mind, this is *NOT SAFE* to use with external input.
More information available here: https://erlang.org/doc/man/erlang.html#binary_to_term-2
"""
use Ash.Type
@constraints [
arity: [
type: :pos_integer,
doc: "Enforces a specific arity on the provided function"
]
]
@impl true
def storage_type(_), do: :binary
@impl true
def constraints, do: @constraints
@impl true
def apply_constraints(term, constraints) do
if constraints[:arity] && not is_function(term, constraints[:arity]) do
{:error, message: "Expected a function of arity %{arity}", arity: constraints[:arity]}
else
{:ok, term}
end
end
@impl true
def matches_type?(v, _constraints) do
is_function(v)
end
@impl true
def cast_input(value, _) when is_function(value) do
{:ok, value}
end
def cast_input(_, _), do: :error
@impl true
def cast_stored(nil, _), do: {:ok, nil}
# sobelow_skip ["Misc.BinToTerm"]
def cast_stored(value, _) do
case Ecto.Type.load(:binary, value) do
{:ok, val} ->
case :erlang.binary_to_term(val, [:safe]) do
function when is_function(function) ->
function
_ ->
:error
end
other ->
other
end
rescue
_ ->
:error
end
@impl true
def dump_to_native(nil, _), do: {:ok, nil}
def dump_to_native(value, _) do
Ecto.Type.dump(:binary, :erlang.term_to_binary(value))
end
end