ghc-9.6.3: The GHC API

Safe Haskell | Safe-Inferred
Language | Haskell2010

GHC.Core.TyCo.Compare

Contents

- Type comparison
- Visiblity comparision

Description

Type equality and comparison

Synopsis

- eqType :: Type -> Type -> Bool
- eqTypeX :: RnEnv2 -> Type -> Type -> Bool
- eqTypes :: [Type] -> [Type] -> Bool
- nonDetCmpType :: Type -> Type -> Ordering
- nonDetCmpTypes :: [Type] -> [Type] -> Ordering
- nonDetCmpTypeX :: RnEnv2 -> Type -> Type -> Ordering
- nonDetCmpTypesX :: RnEnv2 -> [Type] -> [Type] -> Ordering
- nonDetCmpTc :: TyCon -> TyCon -> Ordering
- eqVarBndrs :: RnEnv2 -> [Var] -> [Var] -> Maybe RnEnv2
- pickyEqType :: Type -> Type -> Bool
- tcEqType :: HasDebugCallStack => Type -> Type -> Bool
- tcEqKind :: HasDebugCallStack => Kind -> Kind -> Bool
- tcEqTypeNoKindCheck :: Type -> Type -> Bool
- tcEqTypeVis :: Type -> Type -> Bool
- tcEqTyConApps :: TyCon -> [Type] -> TyCon -> [Type] -> Bool
- eqForAllVis :: ForAllTyFlag -> ForAllTyFlag -> Bool
- cmpForAllVis :: ForAllTyFlag -> ForAllTyFlag -> Ordering

# Type comparison

eqType :: Type -> Type -> Bool Source #

Type equality on source types. Does not look through `newtypes`, `PredType`s or type families, but it does look through type synonyms. This first checks that the kinds of the types are equal and then checks whether the types are equal, ignoring casts and coercions. (The kind check is a recursive call, but since all kinds have type `Type`, there is no need to check the types of kinds.) See also Note [Non-trivial definitional equality] in GHC.Core.TyCo.Rep.

eqTypeX :: RnEnv2 -> Type -> Type -> Bool Source #

Compare types with respect to a (presumably) non-empty `RnEnv2`.

eqTypes :: [Type] -> [Type] -> Bool Source #

Type equality on lists of types, looking through type synonyms but not newtypes.

nonDetCmpType :: Type -> Type -> Ordering Source #

nonDetCmpTypes :: [Type] -> [Type] -> Ordering Source #

nonDetCmpTypeX :: RnEnv2 -> Type -> Type -> Ordering Source #

nonDetCmpTypesX :: RnEnv2 -> [Type] -> [Type] -> Ordering Source #

nonDetCmpTc :: TyCon -> TyCon -> Ordering Source #

Compare two `TyCon`s. See Note [nonDetCmpType nondeterminism]

eqVarBndrs :: RnEnv2 -> [Var] -> [Var] -> Maybe RnEnv2 Source #

pickyEqType :: Type -> Type -> Bool Source #

Like `pickyEqTypeVis`, but returns a Bool for convenience

tcEqType :: HasDebugCallStack => Type -> Type -> Bool Source #

tcEqType implements typechecker equality It behaves just like eqType, but is implemented differently (for now)

tcEqKind :: HasDebugCallStack => Kind -> Kind -> Bool Source #

tcEqTypeNoKindCheck :: Type -> Type -> Bool Source #

Just like `tcEqType`, but will return True for types of different kinds as long as their non-coercion structure is identical.

tcEqTypeVis :: Type -> Type -> Bool Source #

Like `tcEqType`, but returns True if the visible part of the types are equal, even if they are really unequal (in the invisible bits)

tcEqTyConApps :: TyCon -> [Type] -> TyCon -> [Type] -> Bool Source #

Check whether two TyConApps are the same; if the number of arguments are different, just checks the common prefix of arguments.

# Visiblity comparision

eqForAllVis :: ForAllTyFlag -> ForAllTyFlag -> Bool Source #

Do these denote the same level of visibility? `Required` arguments are visible, others are not. So this function equates `Specified` and `Inferred`. Used for printing.

cmpForAllVis :: ForAllTyFlag -> ForAllTyFlag -> Ordering Source #

Do these denote the same level of visibility? `Required` arguments are visible, others are not. So this function equates `Specified` and `Inferred`. Used for printing.