| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Language.Souffle.Internal.Constraints
Description
A helper module for generating more user friendly type errors in the form of custom constraints. This is an internal module, not meant to be used directly.
Synopsis
- type family SimpleProduct (a :: Type) (f :: Type -> Type) :: Constraint where ...
Documentation
type family SimpleProduct (a :: Type) (f :: Type -> Type) :: Constraint where ... Source #
A helper type family used for generating a more user-friendly type error
for incompatible types when generically deriving marshalling code for
the Marshal typeclass.
The a type parameter is the original type, used when displaying the type error. The f type parameter should be equal to 'Rep a', used for analyzing the structure of the data type.
A type error is returned if the passed in type is not a simple product type consisting of only simple types like Int32, String and Text.
Equations
| SimpleProduct a f = (ProductLike a f, OnlySimpleFields a f) |