Shape is library that allows you to declaratively describe and validate your data structures.
To use add
[{:shape, "0.0.2"}]
to your mix dependencies.
Example Usage:
iex> alias Shape, as: S
nil
iex> S.validate(S.Num, 42)
:ok
iex> S.validate(S.Num, "42")
{:error, "42 is not a number"}
# Check list shape
iex> S.validate([S.Atom, S.Str, S.Int], [:a, "b", 1])
:ok
iex> S.validate([S.Int], [1, 2, 3])
:ok
iex> S.validate([S.Str, S.Int, S.Int], [:a, "b", 1])
{:error, ["a is not a string", "b is not a integer"]}
# Check map shape
iex> S.validate(%{S.Atom => S.Str}, %{o: "k"})
:ok
iex> S.validate(%{S.Atom => S.Int, S.Str => S.Int}, %{"o" => "k", "o" => :k})
{:error, ["o is not a atom", "k is not a integer"]}
# Check map key values rather than types
iex> S.validate(%{:o => S.Str, "o" => S.Str}, %{:o => "k", "o" => "k"})
:ok
iex> S.validate(%{:b => S.Str, "o" => S.Str}, %{:o => "k", "o" => "k"})
{:error, ["o is not equal to b"]}
# check Keyword list shape
iex> S.validate([o: S.Str, a: S.Str], [o: "k", a: "ok"])
:ok
iex> S.validate([o: S.Int, b: S.Str], [o: "k", a: "ok"])
{:error, ["a is not equal to b", "k is not a integer"]}