Rerefined.Predicate.Common

Handy utilities for defining predicates.

Re-exports

module Rerefined.Predicate

newtype Typeably a

Wrapper for using with DerivingVia for instances which may be defined using the data type's Typeable instance.

The Typeable version of Generically.

Constructors

Typeably a

Instances

Typeable a => Predicate (Typeably a :: Type)

Fill out predicate metadata using its Typeable instance.

Do not use this for combinator predicates. Doing so will incur insidious Typeable contexts for the wrapped predicate(s).

Defined in Rerefined.Predicate

Methods

predicateName :: Proxy# (Typeably a) -> Int -> ShowS

class Typeable (a :: k)

The class Typeable allows a concrete representation of a type to be calculated.

Minimal complete definition

typeRep#

proxy# :: forall {k} (a :: k). Proxy# a

Witness for an unboxed Proxy# value, which has no runtime representation.

Predicate validation

validateFail :: forall p. Predicate p => Proxy# p -> String -> [RefineFailure String] -> Maybe (RefineFailure String)

Shortcut for returning a predicate validation failure.

validateBool :: Predicate p => Proxy# p -> String -> Bool -> Maybe (RefineFailure String)

Shortcut for simply validating a Bool.

Predicate name

predicateName1 :: forall p. Predicate p => String -> Int -> ShowS

predicateName2 :: forall l r. (Predicate l, Predicate r) => String -> Int -> ShowS