Language.Haskell.TH.Lens

Lenses and Traversals for working with Template Haskell

Documentation

class HasName t where

Has a Name

Methods

name :: Lens' t Name

Extract (or modify) the Name of something

Instances

HasName Name

HasName TyVarBndr

HasName Con

class HasTypeVars t where

Provides for the extraction of free type variables, and alpha renaming.

Methods

typeVarsEx :: Set Name -> Traversal' t Name

When performing substitution into this traversal you're not allowed to substitute in a name that is bound internally or you'll violate the Traversal laws, when in doubt generate your names with newName.

Instances

HasTypeVars Type

HasTypeVars Name

HasTypeVars Pred

HasTypeVars TyVarBndr

HasTypeVars Con

HasTypeVars t => HasTypeVars [t]

class SubstType t where

Provides substitution for types

Methods

substType :: Map Name Type -> t -> t

Perform substitution for types

Instances

SubstType Type

SubstType Pred

SubstType t => SubstType [t]

typeVars :: HasTypeVars t => Traversal' t Name

Traverse free type variables

substTypeVars :: HasTypeVars t => Map Name Name -> t -> t

Substitute using a map of names in for free type variables

conFields :: Traversal' Con StrictType

Provides a Traversal of the types of each field of a constructor.

conNamedFields :: Traversal' Con VarStrictType

Traversal of the types of the named fields of a constructor.