sanctuary-useless
This package exports a single value, Useless
, the sole member of the
sanctuary-useless/Useless type:
// Useless :: Uselessconst Useless = ;
Useless
, as its name suggests, has no functionality. This makes it useful
for testing algebraic data types which satisfy various type classes.
The following assertion, in isolation, suggests that Identity a
satisfies
Z.Setoid
for all a
:
true;
Identity Useless
, though, does not satisfy Z.Setoid
, indicating that
a
is constrained in some way:
false; true;
Conversely, one can use Useless
to demonstrate universal quantification
where applicable:
true;