View Source Witchcraft.Setoid (Witchcraft v1.0.6-doma)
A setoid is a type with an equivalence relation.
This is most useful when equivalence of some data is not the same as equality.
Since some types have differing concepts of equality, this allows overriding
the behaviour from Kernel.==/2
. To get the Setoid ==
operator override,
simply use Witchcraft.Setoid
.
type-class
Type Class
An instance of Witchcraft.Setoid
must define Witchcraft.Setoid.equivalent?/2
Setoid [equivalent?/2]
Link to this section Summary
Link to this section Types
@type t() :: any()
Link to this section Functions
Compare two setoids and determine if they are equivalent.
Aliased as ==
.
examples
Examples
iex> equivalent?(1, 2)
false
iex> import Kernel, except: [==: 2, !=: 2]
...> %{a: 1} == %{a: 1, b: 2}
false
equivalent?(%Maybe.Just{just: 42}, %Maybe.Nothing{})
#=> false
equivalence-not-equality
Equivalence not equality
baby_harry = %Wizard{name: "Harry Potter", age: 10}
old_harry = %Wizard{name: "Harry Potter", age: 17}
def chosen_one?(some_wizard), do: equivalent?(baby_harry, some_wizard)
chosen_one?(old_harry)
#=> true
The opposite of equivalent?/2
.
examples
Examples
iex> nonequivalent?(1, 2)
true