View Source TypeCheck.Builtin.None (TypeCheck v0.13.7)
The 'none' type has no inhabitants. In other words, no value will typecheck against this type.
This means that we always return a problem tuple with :no_match as reason in its check.
It also means that the StreamData-generator will not generate any values;
instead, it will filter away values that would have been produced by none(),
meaning that if you attempt to use none() directly in a generator, you might get a StreamData.FilterTooNarrowError.
However, it's still possible to combine it with other types like :ok | :error | none() and e.g. use the resulting generator of that.
Summary
Types
(This type is managed by TypeCheck,
which allows checking values against the type at runtime.)
Full definition:
problem_tuple :: {t(), :no_match, %{}, val :: any()}@type t() :: %TypeCheck.Builtin.None{}
(This type is managed by TypeCheck,
which allows checking values against the type at runtime.)
Full definition:
t :: %TypeCheck.Builtin.None{}