-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Structural assertions on generic data representations.
--   
--   Please see README.md.
@package generic-data-asserts
@version 0.2.0


-- | Descriptive type errors for generic representation assertion failures.
--   
--   These are potentially useful separately from the asserts, in places
--   where we're unable to perform asserts which evaluate to
--   <tt>Constraint</tt>s e.g. type families, so we expose them neatly
--   here.
module Generic.Data.Rep.Error
type GAssertError a msg = TypeError ('Text "Assertion on generic representation failed for type: " :<>: 'ShowType a :$$: 'Text "Message: " :<>: 'Text msg)
type GAssertErrorVoid a = GAssertError a "not non-void type (>=1 constructor)"
type GAssertErrorSum a = GAssertError a "not non-sum type (1 constructor)"
type GAssertErrorNotSum a = GAssertError a "not sum type (>=2 constructors)"
type GAssertErrorNotEnum a = GAssertError a "not enum type (all empty constructors)"


-- | Structural assertions on generic data representation.
module Generic.Data.Rep.Assert
type family StripD1 a

-- | Type is not void i.e. has at least one constructor.
type GAssertNotVoid a = Assert (IsNotVoid (StripD1 (Rep a))) (GAssertErrorVoid a)
type family IsNotVoid a

-- | Type is not a sum type i.e. has at most one constructor.
--   
--   Permits void types.
type GAssertNotSum a = Assert (IsNotSum (StripD1 (Rep a))) (GAssertErrorSum a)
type family IsNotSum a

-- | Type is a sum type i.e. has &gt;=2 constructors.
--   
--   Permits void types.
type GAssertSum a = Assert (IsSum (StripD1 (Rep a))) (GAssertErrorNotSum a)
type family IsSum a

-- | Type has only empty constructors.
--   
--   Permits void types.
type GAssertEnum a = Assert (IsEnum (StripD1 (Rep a))) (GAssertErrorNotEnum a)
type family IsEnum a
type family ConsIsEmpty a

-- | Type level boolean AND.
type family And l r