CurryInfo: base-3.3.0 / Prelude.Data

class Data a where
  (===)  :: a -> a -> Bool
  aValue :: a

--- The class `Data` defines a strict equality operator `===`
--- and a non-deterministic operation `aValue` which yields
--- all values of the given type.
--- To ensure that the operator `===` always corresponds to the
--- syntactic equality of values and `aValue ` enumerates all values,
--- instances of `Data` are automatically derived and cannot be
--- defined in a valid Curry program.
--- For data types contain functional values, `Data` instances
--- are not derived.
--- Free variables have always a data context to ensure that possible
--- values for the type of the free variable can be enumerated.
---
--- Note that the class `Data` is different from the class `Eq`,
--- since the latter defines only an equivalence relation rather
--- than syntactic equality.

["(===) :: a -> a -> Bool","aValue :: a"]

Data