Data.Express.Utils.TH

Template Haskell utilities.

Documentation

reallyDeriveCascading :: Name -> (Name -> DecsQ) -> Name -> DecsQ

deriveWhenNeeded :: Name -> (Name -> DecsQ) -> Name -> DecsQ

deriveWhenNeededOrWarn :: Name -> (Name -> DecsQ) -> Name -> DecsQ

typeConArgs :: Name -> Q [Name]

typeConArgsThat :: Name -> (Name -> Q Bool) -> Q [Name]

typeConCascadingArgsThat :: Name -> (Name -> Q Bool) -> Q [Name]

normalizeType :: Name -> Q (Type, [Type])

normalizeTypeUnits :: Name -> Q Type

isInstanceOf :: Name -> Name -> Q Bool

isntInstanceOf :: Name -> Name -> Q Bool

typeArity :: Name -> Q Int

Given a type name, return the number of arguments taken by that type. Examples in partially broken TH:

arity ''Int        === Q 0
arity ''Int->Int   === Q 0
arity ''Maybe      === Q 1
arity ''Either     === Q 2
arity ''Int->      === Q 1

This works for Data's and Newtype's and it is useful when generating typeclass instances.

typeConstructors :: Name -> Q [(Name, [Type])]

isTypeSynonym :: Name -> Q Bool

typeSynonymType :: Name -> Q Type

mergeIFns :: DecsQ -> DecsQ

mergeI :: DecsQ -> DecsQ -> DecsQ

lookupValN :: String -> Q Name

showJustName :: Name -> String

typeConstructorsArgNames :: Name -> Q [(Name, [Name])]

(|=>|) :: Cxt -> DecsQ -> DecsQ

(|++|) :: DecsQ -> DecsQ -> DecsQ

whereI :: DecsQ -> [Dec] -> DecsQ

module Language.Haskell.TH