{- (c) The University of Glasgow 2006 (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 HsTypes: Abstract syntax: user-defined types -} {-# LANGUAGE DeriveDataTypeable #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE FlexibleInstances #-} {-# LANGUAGE StandaloneDeriving #-} {-# LANGUAGE TypeSynonymInstances #-} {-# LANGUAGE UndecidableInstances #-} -- Note [Pass sensitive types] -- in module PlaceHolder {-# LANGUAGE ConstraintKinds #-} {-# LANGUAGE CPP #-} module HsTypes ( HsType(..), LHsType, HsKind, LHsKind, HsTyVarBndr(..), LHsTyVarBndr, LHsQTyVars(..), HsImplicitBndrs(..), HsWildCardBndrs(..), LHsSigType, LHsSigWcType, LHsWcType, HsTupleSort(..), HsContext, LHsContext, HsTyLit(..), HsIPName(..), hsIPNameFS, HsAppType(..),LHsAppType, LBangType, BangType, HsSrcBang(..), HsImplBang(..), SrcStrictness(..), SrcUnpackedness(..), getBangType, getBangStrictness, ConDeclField(..), LConDeclField, pprConDeclFields, updateGadtResult, HsConDetails(..), FieldOcc(..), LFieldOcc, mkFieldOcc, AmbiguousFieldOcc(..), mkAmbiguousFieldOcc, rdrNameAmbiguousFieldOcc, selectorAmbiguousFieldOcc, unambiguousFieldOcc, ambiguousFieldOcc, HsWildCardInfo(..), mkAnonWildCardTy, wildCardName, sameWildCard, mkHsImplicitBndrs, mkHsWildCardBndrs, hsImplicitBody, mkEmptyImplicitBndrs, mkEmptyWildCardBndrs, mkHsQTvs, hsQTvExplicit, emptyLHsQTvs, isEmptyLHsQTvs, isHsKindedTyVar, hsTvbAllKinded, hsScopedTvs, hsWcScopedTvs, dropWildCards, hsTyVarName, hsAllLTyVarNames, hsLTyVarLocNames, hsLTyVarName, hsLTyVarLocName, hsExplicitLTyVarNames, splitLHsInstDeclTy, getLHsInstDeclHead, getLHsInstDeclClass_maybe, splitLHsPatSynTy, splitLHsForAllTy, splitLHsQualTy, splitLHsSigmaTy, splitHsFunType, splitHsAppsTy, splitHsAppTys, getAppsTyHead_maybe, hsTyGetAppHead_maybe, mkHsOpTy, mkHsAppTy, mkHsAppTys, ignoreParens, hsSigType, hsSigWcType, hsLTyVarBndrToType, hsLTyVarBndrsToTypes, -- Printing pprParendHsType, pprHsForAll, pprHsForAllTvs, pprHsForAllExtra, pprHsContext, pprHsContextNoArrow, pprHsContextMaybe ) where import {-# SOURCE #-} HsExpr ( HsSplice, pprSplice ) import PlaceHolder ( PostTc,PostRn,DataId,PlaceHolder(..) ) import Id ( Id ) import Name( Name ) import RdrName ( RdrName ) import NameSet ( NameSet, emptyNameSet ) import DataCon( HsSrcBang(..), HsImplBang(..), SrcStrictness(..), SrcUnpackedness(..) ) import TysPrim( funTyConName ) import Type import HsDoc import BasicTypes import SrcLoc import StaticFlags import Outputable import FastString import Maybes( isJust ) import Data.Data hiding ( Fixity ) import Data.Maybe ( fromMaybe ) import Control.Monad ( unless ) #if __GLASGOW_HASKELL > 710 import Data.Semigroup ( Semigroup ) import qualified Data.Semigroup as Semigroup #endif {- ************************************************************************ * * \subsection{Bang annotations} * * ************************************************************************ -} type LBangType name = Located (BangType name) type BangType name = HsType name -- Bangs are in the HsType data type getBangType :: LHsType a -> LHsType a getBangType (L _ (HsBangTy _ ty)) = ty getBangType ty = ty getBangStrictness :: LHsType a -> HsSrcBang getBangStrictness (L _ (HsBangTy s _)) = s getBangStrictness _ = (HsSrcBang Nothing NoSrcUnpack NoSrcStrict) {- ************************************************************************ * * \subsection{Data types} * * ************************************************************************ This is the syntax for types as seen in type signatures. Note [HsBSig binder lists] ~~~~~~~~~~~~~~~~~~~~~~~~~~ Consider a binder (or pattern) decorated with a type or kind, \ (x :: a -> a). blah forall (a :: k -> *) (b :: k). blah Then we use a LHsBndrSig on the binder, so that the renamer can decorate it with the variables bound by the pattern ('a' in the first example, 'k' in the second), assuming that neither of them is in scope already See also Note [Kind and type-variable binders] in RnTypes Note [HsType binders] ~~~~~~~~~~~~~~~~~~~~~ The system for recording type and kind-variable binders in HsTypes is a bit complicated. Here's how it works. * In a HsType, HsForAllTy represents an /explicit, user-written/ 'forall' e.g. forall a b. ... HsQualTy represents an /explicit, user-written/ context e.g. (Eq a, Show a) => ... The context can be empty if that's what the user wrote These constructors represent what the user wrote, no more and no less. * HsTyVarBndr describes a quantified type variable written by the user. For example f :: forall a (b :: *). blah here 'a' and '(b::*)' are each a HsTyVarBndr. A HsForAllTy has a list of LHsTyVarBndrs. * HsImplicitBndrs is a wrapper that gives the implicitly-quantified kind and type variables of the wrapped thing. It is filled in by the renamer. For example, if the user writes f :: a -> a the HsImplicitBinders binds the 'a' (not a HsForAllTy!). NB: this implicit quantification is purely lexical: we bind any type or kind variables that are not in scope. The type checker may subsequently quantify over further kind variables. * HsWildCardBndrs is a wrapper that binds the wildcard variables of the wrapped thing. It is filled in by the renamer f :: _a -> _ The enclosing HsWildCardBndrs binds the wildcards _a and _. * The explicit presence of these wrappers specifies, in the HsSyn, exactly where implicit quantification is allowed, and where wildcards are allowed. * LHsQTyVars is used in data/class declarations, where the user gives explicit *type* variable bindings, but we need to implicitly bind *kind* variables. For example class C (a :: k -> *) where ... The 'k' is implicitly bound in the hsq_tvs field of LHsQTyVars Note [The wildcard story for types] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Types can have wildcards in them, to support partial type signatures, like f :: Int -> (_ , _a) -> _a A wildcard in a type can be * An anonymous wildcard, written '_' In HsType this is represented by HsWildCardTy. After the renamer, this contains a Name which uniquely identifies this particular occurrence. * A named wildcard, written '_a', '_foo', etc In HsType this is represented by (HsTyVar "_a") i.e. a perfectly ordinary type variable that happens to start with an underscore Note carefully: * When NamedWildCards is off, type variables that start with an underscore really /are/ ordinary type variables. And indeed, even when NamedWildCards is on you can bind _a explicitly as an ordinary type variable: data T _a _b = MkT _b _a Or even: f :: forall _a. _a -> _b Here _a is an ordinary forall'd binder, but (With NamedWildCards) _b is a named wildcard. (See the comments in Trac #10982) * All wildcards, whether named or anonymous, are bound by the HsWildCardBndrs construct, which wraps types that are allowed to have wildcards. * After type checking is done, we report what types the wildcards got unified with. -} type LHsContext name = Located (HsContext name) -- ^ 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnUnit' -- For details on above see note [Api annotations] in ApiAnnotation type HsContext name = [LHsType name] type LHsType name = Located (HsType name) -- ^ May have 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnComma' when -- in a list -- For details on above see note [Api annotations] in ApiAnnotation type HsKind name = HsType name type LHsKind name = Located (HsKind name) -- ^ 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnDcolon' -- For details on above see note [Api annotations] in ApiAnnotation -------------------------------------------------- -- LHsQTyVars -- The explicitly-quantified binders in a data/type declaration type LHsTyVarBndr name = Located (HsTyVarBndr name) -- See Note [HsType binders] data LHsQTyVars name -- See Note [HsType binders] = HsQTvs { hsq_implicit :: PostRn name [Name] -- implicit (dependent) variables , hsq_explicit :: [LHsTyVarBndr name] -- explicit variables -- See Note [HsForAllTy tyvar binders] , hsq_dependent :: PostRn name NameSet -- which explicit vars are dependent -- See Note [Dependent LHsQTyVars] in TcHsType } deriving( Typeable ) deriving instance (DataId name) => Data (LHsQTyVars name) mkHsQTvs :: [LHsTyVarBndr RdrName] -> LHsQTyVars RdrName mkHsQTvs tvs = HsQTvs { hsq_implicit = PlaceHolder, hsq_explicit = tvs , hsq_dependent = PlaceHolder } hsQTvExplicit :: LHsQTyVars name -> [LHsTyVarBndr name] hsQTvExplicit = hsq_explicit emptyLHsQTvs :: LHsQTyVars Name emptyLHsQTvs = HsQTvs [] [] emptyNameSet isEmptyLHsQTvs :: LHsQTyVars Name -> Bool isEmptyLHsQTvs (HsQTvs [] [] _) = True isEmptyLHsQTvs _ = False ------------------------------------------------ -- HsImplicitBndrs -- Used to quantify the binders of a type in cases -- when a HsForAll isn't appropriate: -- * Patterns in a type/data family instance (HsTyPats) -- * Type of a rule binder (RuleBndr) -- * Pattern type signatures (SigPatIn) -- In the last of these, wildcards can happen, so we must accommodate them data HsImplicitBndrs name thing -- See Note [HsType binders] = HsIB { hsib_vars :: PostRn name [Name] -- Implicitly-bound kind & type vars , hsib_body :: thing -- Main payload (type or list of types) } deriving (Typeable) data HsWildCardBndrs name thing -- See Note [HsType binders] -- See Note [The wildcard story for types] = HsWC { hswc_wcs :: PostRn name [Name] -- Wild cards, both named and anonymous , hswc_ctx :: Maybe SrcSpan -- Indicates whether hswc_body has an -- extra-constraint wildcard, and if so where -- e.g. (Eq a, _) => a -> a -- NB: the wildcard stays in HsQualTy inside the type! -- So for pretty printing purposes you can ignore -- hswc_ctx , hswc_body :: thing -- Main payload (type or list of types) } deriving( Typeable ) deriving instance (Data name, Data thing, Data (PostRn name [Name])) => Data (HsImplicitBndrs name thing) deriving instance (Data name, Data thing, Data (PostRn name [Name])) => Data (HsWildCardBndrs name thing) type LHsSigType name = HsImplicitBndrs name (LHsType name) -- Implicit only type LHsWcType name = HsWildCardBndrs name (LHsType name) -- Wildcard only type LHsSigWcType name = HsImplicitBndrs name (LHsWcType name) -- Both -- See Note [Representing type signatures] hsImplicitBody :: HsImplicitBndrs name thing -> thing hsImplicitBody (HsIB { hsib_body = body }) = body hsSigType :: LHsSigType name -> LHsType name hsSigType = hsImplicitBody hsSigWcType :: LHsSigWcType name -> LHsType name hsSigWcType sig_ty = hswc_body (hsib_body sig_ty) dropWildCards :: LHsSigWcType name -> LHsSigType name -- Drop the wildcard part of a LHsSigWcType dropWildCards sig_ty = sig_ty { hsib_body = hsSigWcType sig_ty } {- Note [Representing type signatures] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ HsSigType is used to represent an explicit user type signature such as f :: a -> a or g (x :: a -> a) = x A HsSigType is just a HsImplicitBndrs wrapping a LHsType. * The HsImplicitBndrs binds the /implicitly/ quantified tyvars * The LHsType binds the /explictly/ quantified tyvars E.g. For a signature like f :: forall (a::k). blah we get HsIB { hsib_vars = [k] , hsib_body = HsForAllTy { hst_bndrs = [(a::*)] , hst_body = blah } The implicit kind variable 'k' is bound by the HsIB; the explictly forall'd tyvar 'a' is bounnd by the HsForAllTy -} mkHsImplicitBndrs :: thing -> HsImplicitBndrs RdrName thing mkHsImplicitBndrs x = HsIB { hsib_body = x , hsib_vars = PlaceHolder } mkHsWildCardBndrs :: thing -> HsWildCardBndrs RdrName thing mkHsWildCardBndrs x = HsWC { hswc_body = x , hswc_wcs = PlaceHolder , hswc_ctx = Nothing } -- Add empty binders. This is a bit suspicious; what if -- the wrapped thing had free type variables? mkEmptyImplicitBndrs :: thing -> HsImplicitBndrs Name thing mkEmptyImplicitBndrs x = HsIB { hsib_body = x , hsib_vars = [] } mkEmptyWildCardBndrs :: thing -> HsWildCardBndrs Name thing mkEmptyWildCardBndrs x = HsWC { hswc_body = x , hswc_wcs = [] , hswc_ctx = Nothing } -------------------------------------------------- -- | These names are used early on to store the names of implicit -- parameters. They completely disappear after type-checking. newtype HsIPName = HsIPName FastString deriving( Eq, Data, Typeable ) hsIPNameFS :: HsIPName -> FastString hsIPNameFS (HsIPName n) = n instance Outputable HsIPName where ppr (HsIPName n) = char '?' <> ftext n -- Ordinary implicit parameters instance OutputableBndr HsIPName where pprBndr _ n = ppr n -- Simple for now pprInfixOcc n = ppr n pprPrefixOcc n = ppr n -------------------------------------------------- data HsTyVarBndr name = UserTyVar -- no explicit kinding (Located name) -- See Note [Located RdrNames] in HsExpr | KindedTyVar (Located name) (LHsKind name) -- The user-supplied kind signature -- ^ -- - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnOpen', -- 'ApiAnnotation.AnnDcolon', 'ApiAnnotation.AnnClose' -- For details on above see note [Api annotations] in ApiAnnotation deriving (Typeable) deriving instance (DataId name) => Data (HsTyVarBndr name) -- | Does this 'HsTyVarBndr' come with an explicit kind annotation? isHsKindedTyVar :: HsTyVarBndr name -> Bool isHsKindedTyVar (UserTyVar {}) = False isHsKindedTyVar (KindedTyVar {}) = True -- | Do all type variables in this 'LHsQTyVars' come with kind annotations? hsTvbAllKinded :: LHsQTyVars name -> Bool hsTvbAllKinded = all (isHsKindedTyVar . unLoc) . hsQTvExplicit data HsType name = HsForAllTy -- See Note [HsType binders] { hst_bndrs :: [LHsTyVarBndr name] -- Explicit, user-supplied 'forall a b c' , hst_body :: LHsType name -- body type } -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnForall', -- 'ApiAnnotation.AnnDot','ApiAnnotation.AnnDarrow' -- For details on above see note [Api annotations] in ApiAnnotation | HsQualTy -- See Note [HsType binders] { hst_ctxt :: LHsContext name -- Context C => blah , hst_body :: LHsType name } | HsTyVar (Located name) -- Type variable, type constructor, or data constructor -- see Note [Promotions (HsTyVar)] -- See Note [Located RdrNames] in HsExpr -- ^ - 'ApiAnnotation.AnnKeywordId' : None -- For details on above see note [Api annotations] in ApiAnnotation | HsAppsTy [LHsAppType name] -- Used only before renaming, -- Note [HsAppsTy] -- ^ - 'ApiAnnotation.AnnKeywordId' : None | HsAppTy (LHsType name) (LHsType name) -- ^ - 'ApiAnnotation.AnnKeywordId' : None -- For details on above see note [Api annotations] in ApiAnnotation | HsFunTy (LHsType name) -- function type (LHsType name) -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnRarrow', -- For details on above see note [Api annotations] in ApiAnnotation | HsListTy (LHsType name) -- Element type -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnOpen' @'['@, -- 'ApiAnnotation.AnnClose' @']'@ -- For details on above see note [Api annotations] in ApiAnnotation | HsPArrTy (LHsType name) -- Elem. type of parallel array: [:t:] -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnOpen' @'[:'@, -- 'ApiAnnotation.AnnClose' @':]'@ -- For details on above see note [Api annotations] in ApiAnnotation | HsTupleTy HsTupleSort [LHsType name] -- Element types (length gives arity) -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnOpen' @'(' or '(#'@, -- 'ApiAnnotation.AnnClose' @')' or '#)'@ -- For details on above see note [Api annotations] in ApiAnnotation | HsOpTy (LHsType name) (Located name) (LHsType name) -- ^ - 'ApiAnnotation.AnnKeywordId' : None -- For details on above see note [Api annotations] in ApiAnnotation | HsParTy (LHsType name) -- See Note [Parens in HsSyn] in HsExpr -- Parenthesis preserved for the precedence re-arrangement in RnTypes -- It's important that a * (b + c) doesn't get rearranged to (a*b) + c! -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnOpen' @'('@, -- 'ApiAnnotation.AnnClose' @')'@ -- For details on above see note [Api annotations] in ApiAnnotation | HsIParamTy HsIPName -- (?x :: ty) (LHsType name) -- Implicit parameters as they occur in contexts -- ^ -- > (?x :: ty) -- -- - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnDcolon' -- For details on above see note [Api annotations] in ApiAnnotation | HsEqTy (LHsType name) -- ty1 ~ ty2 (LHsType name) -- Always allowed even without TypeOperators, and has special kinding rule -- ^ -- > ty1 ~ ty2 -- -- - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnTilde' -- For details on above see note [Api annotations] in ApiAnnotation | HsKindSig (LHsType name) -- (ty :: kind) (LHsKind name) -- A type with a kind signature -- ^ -- > (ty :: kind) -- -- - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnOpen' @'('@, -- 'ApiAnnotation.AnnDcolon','ApiAnnotation.AnnClose' @')'@ -- For details on above see note [Api annotations] in ApiAnnotation | HsSpliceTy (HsSplice name) -- Includes quasi-quotes (PostTc name Kind) -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnOpen' @'$('@, -- 'ApiAnnotation.AnnClose' @')'@ -- For details on above see note [Api annotations] in ApiAnnotation | HsDocTy (LHsType name) LHsDocString -- A documented type -- ^ - 'ApiAnnotation.AnnKeywordId' : None -- For details on above see note [Api annotations] in ApiAnnotation | HsBangTy HsSrcBang (LHsType name) -- Bang-style type annotations -- ^ - 'ApiAnnotation.AnnKeywordId' : -- 'ApiAnnotation.AnnOpen' @'{-\# UNPACK' or '{-\# NOUNPACK'@, -- 'ApiAnnotation.AnnClose' @'#-}'@ -- 'ApiAnnotation.AnnBang' @\'!\'@ -- For details on above see note [Api annotations] in ApiAnnotation | HsRecTy [LConDeclField name] -- Only in data type declarations -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnOpen' @'{'@, -- 'ApiAnnotation.AnnClose' @'}'@ -- For details on above see note [Api annotations] in ApiAnnotation | HsCoreTy Type -- An escape hatch for tunnelling a *closed* -- Core Type through HsSyn. -- ^ - 'ApiAnnotation.AnnKeywordId' : None -- For details on above see note [Api annotations] in ApiAnnotation | HsExplicitListTy -- A promoted explicit list (PostTc name Kind) -- See Note [Promoted lists and tuples] [LHsType name] -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnOpen' @"'["@, -- 'ApiAnnotation.AnnClose' @']'@ -- For details on above see note [Api annotations] in ApiAnnotation | HsExplicitTupleTy -- A promoted explicit tuple [PostTc name Kind] -- See Note [Promoted lists and tuples] [LHsType name] -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnOpen' @"'("@, -- 'ApiAnnotation.AnnClose' @')'@ -- For details on above see note [Api annotations] in ApiAnnotation | HsTyLit HsTyLit -- A promoted numeric literal. -- ^ - 'ApiAnnotation.AnnKeywordId' : None -- For details on above see note [Api annotations] in ApiAnnotation | HsWildCardTy (HsWildCardInfo name) -- A type wildcard -- See Note [The wildcard story for types] -- ^ - 'ApiAnnotation.AnnKeywordId' : None -- For details on above see note [Api annotations] in ApiAnnotation deriving (Typeable) deriving instance (DataId name) => Data (HsType name) -- Note [Literal source text] in BasicTypes for SourceText fields in -- the following data HsTyLit = HsNumTy SourceText Integer | HsStrTy SourceText FastString deriving (Data, Typeable) newtype HsWildCardInfo name -- See Note [The wildcard story for types] = AnonWildCard (PostRn name (Located Name)) -- A anonymous wild card ('_'). A fresh Name is generated for -- each individual anonymous wildcard during renaming deriving (Typeable) deriving instance (DataId name) => Data (HsWildCardInfo name) type LHsAppType name = Located (HsAppType name) -- ^ 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnSimpleQuote' data HsAppType name = HsAppInfix (Located name) -- either a symbol or an id in backticks | HsAppPrefix (LHsType name) -- anything else, including things like (+) deriving (Typeable) deriving instance (DataId name) => Data (HsAppType name) instance OutputableBndr name => Outputable (HsAppType name) where ppr = ppr_app_ty TopPrec {- Note [HsForAllTy tyvar binders] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ After parsing: * Implicit => empty Explicit => the variables the user wrote After renaming * Implicit => the *type* variables free in the type Explicit => the variables the user wrote (renamed) Qualified currently behaves exactly as Implicit, but it is deprecated to use it for implicit quantification. In this case, GHC 7.10 gives a warning; see Note [Context quantification] in RnTypes, and Trac #4426. In GHC 8.0, Qualified will no longer bind variables and this will become an error. The kind variables bound in the hsq_implicit field come both a) from the kind signatures on the kind vars (eg k1) b) from the scope of the forall (eg k2) Example: f :: forall (a::k1) b. T a (b::k2) Note [Unit tuples] ~~~~~~~~~~~~~~~~~~ Consider the type type instance F Int = () We want to parse that "()" as HsTupleTy HsBoxedOrConstraintTuple [], NOT as HsTyVar unitTyCon Why? Because F might have kind (* -> Constraint), so we when parsing we don't know if that tuple is going to be a constraint tuple or an ordinary unit tuple. The HsTupleSort flag is specifically designed to deal with that, but it has to work for unit tuples too. Note [Promotions (HsTyVar)] ~~~~~~~~~~~~~~~~~~~~~~~~~~~ HsTyVar: A name in a type or kind. Here are the allowed namespaces for the name. In a type: Var: not allowed Data: promoted data constructor Tv: type variable TcCls before renamer: type constructor, class constructor, or promoted data constructor TcCls after renamer: type constructor or class constructor In a kind: Var, Data: not allowed Tv: kind variable TcCls: kind constructor or promoted type constructor Note [HsAppsTy] ~~~~~~~~~~~~~~~ How to parse Foo * Int ? Is it `(*) Foo Int` or `Foo GHC.Types.* Int`? There's no way to know until renaming. So we just take type expressions like this and put each component in a list, so be sorted out in the renamer. The sorting out is done by RnTypes.mkHsOpTyRn. This means that the parser should never produce HsAppTy or HsOpTy. Note [Promoted lists and tuples] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Notice the difference between HsListTy HsExplicitListTy HsTupleTy HsExplicitListTupleTy E.g. f :: [Int] HsListTy g3 :: T '[] All these use g2 :: T '[True] HsExplicitListTy g1 :: T '[True,False] g1a :: T [True,False] (can omit ' where unambiguous) kind of T :: [Bool] -> * This kind uses HsListTy! E.g. h :: (Int,Bool) HsTupleTy; f is a pair k :: S '(True,False) HsExplicitTypleTy; S is indexed by a type-level pair of booleans kind of S :: (Bool,Bool) -> * This kind uses HsExplicitTupleTy Note [Distinguishing tuple kinds] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Apart from promotion, tuples can have one of three different kinds: x :: (Int, Bool) -- Regular boxed tuples f :: Int# -> (# Int#, Int# #) -- Unboxed tuples g :: (Eq a, Ord a) => a -- Constraint tuples For convenience, internally we use a single constructor for all of these, namely HsTupleTy, but keep track of the tuple kind (in the first argument to HsTupleTy, a HsTupleSort). We can tell if a tuple is unboxed while parsing, because of the #. However, with -XConstraintKinds we can only distinguish between constraint and boxed tuples during type checking, in general. Hence the four constructors of HsTupleSort: HsUnboxedTuple -> Produced by the parser HsBoxedTuple -> Certainly a boxed tuple HsConstraintTuple -> Certainly a constraint tuple HsBoxedOrConstraintTuple -> Could be a boxed or a constraint tuple. Produced by the parser only, disappears after type checking -} data HsTupleSort = HsUnboxedTuple | HsBoxedTuple | HsConstraintTuple | HsBoxedOrConstraintTuple deriving (Data, Typeable) type LConDeclField name = Located (ConDeclField name) -- ^ May have 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnComma' when -- in a list -- For details on above see note [Api annotations] in ApiAnnotation data ConDeclField name -- Record fields have Haddoc docs on them = ConDeclField { cd_fld_names :: [LFieldOcc name], -- ^ See Note [ConDeclField names] cd_fld_type :: LBangType name, cd_fld_doc :: Maybe LHsDocString } -- ^ - 'ApiAnnotation.AnnKeywordId' : 'ApiAnnotation.AnnDcolon' -- For details on above see note [Api annotations] in ApiAnnotation deriving (Typeable) deriving instance (DataId name) => Data (ConDeclField name) instance (OutputableBndr name) => Outputable (ConDeclField name) where ppr (ConDeclField fld_n fld_ty _) = ppr fld_n <+> dcolon <+> ppr fld_ty -- HsConDetails is used for patterns/expressions *and* for data type -- declarations data HsConDetails arg rec = PrefixCon [arg] -- C p1 p2 p3 | RecCon rec -- C { x = p1, y = p2 } | InfixCon arg arg -- p1 `C` p2 deriving (Data, Typeable) instance (Outputable arg, Outputable rec) => Outputable (HsConDetails arg rec) where ppr (PrefixCon args) = text "PrefixCon" <+> ppr args ppr (RecCon rec) = text "RecCon:" <+> ppr rec ppr (InfixCon l r) = text "InfixCon:" <+> ppr [l, r] -- Takes details and result type of a GADT data constructor as created by the -- parser and rejigs them using information about fixities from the renamer. -- See Note [Sorting out the result type] in RdrHsSyn updateGadtResult :: (Monad m) => (SDoc -> m ()) -> SDoc -> HsConDetails (LHsType Name) (Located [LConDeclField Name]) -- ^ Original details -> LHsType Name -- ^ Original result type -> m (HsConDetails (LHsType Name) (Located [LConDeclField Name]), LHsType Name) updateGadtResult failWith doc details ty = do { let (arg_tys, res_ty) = splitHsFunType ty badConSig = text "Malformed constructor signature" ; case details of InfixCon {} -> pprPanic "updateGadtResult" (ppr ty) RecCon {} -> do { unless (null arg_tys) (failWith (doc <+> badConSig)) ; return (details, res_ty) } PrefixCon {} -> return (PrefixCon arg_tys, res_ty)} {- Note [ConDeclField names] ~~~~~~~~~~~~~~~~~~~~~~~~~ A ConDeclField contains a list of field occurrences: these always include the field label as the user wrote it. After the renamer, it will additionally contain the identity of the selector function in the second component. Due to DuplicateRecordFields, the OccName of the selector function may have been mangled, which is why we keep the original field label separately. For example, when DuplicateRecordFields is enabled data T = MkT { x :: Int } gives ConDeclField { cd_fld_names = [L _ (FieldOcc "x" $sel:x:MkT)], ... }. -} ----------------------- -- A valid type must have a for-all at the top of the type, or of the fn arg -- types --------------------- hsWcScopedTvs :: LHsSigWcType Name -> [Name] -- Get the lexically-scoped type variables of a HsSigType -- - the explicitly-given forall'd type variables -- - the implicitly-bound kind variables -- - the named wildcars; see Note [Scoping of named wildcards] -- because they scope in the same way hsWcScopedTvs sig_ty | HsIB { hsib_vars = vars, hsib_body = sig_ty1 } <- sig_ty , HsWC { hswc_wcs = nwcs, hswc_body = sig_ty2 } <- sig_ty1 = case sig_ty2 of L _ (HsForAllTy { hst_bndrs = tvs }) -> vars ++ nwcs ++ map hsLTyVarName tvs -- include kind variables only if the type is headed by forall -- (this is consistent with GHC 7 behaviour) _ -> nwcs hsScopedTvs :: LHsSigType Name -> [Name] -- Same as hsWcScopedTvs, but for a LHsSigType hsScopedTvs sig_ty | HsIB { hsib_vars = vars, hsib_body = sig_ty2 } <- sig_ty , L _ (HsForAllTy { hst_bndrs = tvs }) <- sig_ty2 = vars ++ map hsLTyVarName tvs | otherwise = [] {- Note [Scoping of named wildcards] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Consider f :: _a -> _a f x = let g :: _a -> _a g = ... in ... Currently, for better or worse, the "_a" variables are all the same. So although there is no explicit forall, the "_a" scopes over the definition. I don't know if this is a good idea, but there it is. -} --------------------- hsTyVarName :: HsTyVarBndr name -> name hsTyVarName (UserTyVar (L _ n)) = n hsTyVarName (KindedTyVar (L _ n) _) = n hsLTyVarName :: LHsTyVarBndr name -> name hsLTyVarName = hsTyVarName . unLoc hsExplicitLTyVarNames :: LHsQTyVars name -> [name] -- Explicit variables only hsExplicitLTyVarNames qtvs = map hsLTyVarName (hsQTvExplicit qtvs) hsAllLTyVarNames :: LHsQTyVars Name -> [Name] -- All variables hsAllLTyVarNames (HsQTvs { hsq_implicit = kvs, hsq_explicit = tvs }) = kvs ++ map hsLTyVarName tvs hsLTyVarLocName :: LHsTyVarBndr name -> Located name hsLTyVarLocName = fmap hsTyVarName hsLTyVarLocNames :: LHsQTyVars name -> [Located name] hsLTyVarLocNames qtvs = map hsLTyVarLocName (hsQTvExplicit qtvs) -- | Convert a LHsTyVarBndr to an equivalent LHsType. hsLTyVarBndrToType :: LHsTyVarBndr name -> LHsType name hsLTyVarBndrToType = fmap cvt where cvt (UserTyVar n) = HsTyVar n cvt (KindedTyVar (L name_loc n) kind) = HsKindSig (L name_loc (HsTyVar (L name_loc n))) kind -- | Convert a LHsTyVarBndrs to a list of types. -- Works on *type* variable only, no kind vars. hsLTyVarBndrsToTypes :: LHsQTyVars name -> [LHsType name] hsLTyVarBndrsToTypes (HsQTvs { hsq_explicit = tvbs }) = map hsLTyVarBndrToType tvbs --------------------- wildCardName :: HsWildCardInfo Name -> Name wildCardName (AnonWildCard (L _ n)) = n -- Two wild cards are the same when they have the same location sameWildCard :: Located (HsWildCardInfo name) -> Located (HsWildCardInfo name) -> Bool sameWildCard (L l1 (AnonWildCard _)) (L l2 (AnonWildCard _)) = l1 == l2 ignoreParens :: LHsType name -> LHsType name ignoreParens (L _ (HsParTy ty)) = ignoreParens ty ignoreParens (L _ (HsAppsTy [L _ (HsAppPrefix ty)])) = ignoreParens ty ignoreParens ty = ty {- ************************************************************************ * * Building types * * ************************************************************************ -} mkAnonWildCardTy :: HsType RdrName mkAnonWildCardTy = HsWildCardTy (AnonWildCard PlaceHolder) mkHsOpTy :: LHsType name -> Located name -> LHsType name -> HsType name mkHsOpTy ty1 op ty2 = HsOpTy ty1 op ty2 mkHsAppTy :: LHsType name -> LHsType name -> LHsType name mkHsAppTy t1 t2 = addCLoc t1 t2 (HsAppTy t1 t2) mkHsAppTys :: LHsType name -> [LHsType name] -> LHsType name mkHsAppTys = foldl mkHsAppTy {- ************************************************************************ * * Decomposing HsTypes * * ************************************************************************ -} --------------------------------- -- splitHsFunType decomposes a type (t1 -> t2 ... -> tn) -- Breaks up any parens in the result type: -- splitHsFunType (a -> (b -> c)) = ([a,b], c) -- Also deals with (->) t1 t2; that is why it only works on LHsType Name -- (see Trac #9096) splitHsFunType :: LHsType Name -> ([LHsType Name], LHsType Name) splitHsFunType (L _ (HsParTy ty)) = splitHsFunType ty splitHsFunType (L _ (HsFunTy x y)) | (args, res) <- splitHsFunType y = (x:args, res) splitHsFunType orig_ty@(L _ (HsAppTy t1 t2)) = go t1 [t2] where -- Look for (->) t1 t2, possibly with parenthesisation go (L _ (HsTyVar (L _ fn))) tys | fn == funTyConName , [t1,t2] <- tys , (args, res) <- splitHsFunType t2 = (t1:args, res) go (L _ (HsAppTy t1 t2)) tys = go t1 (t2:tys) go (L _ (HsParTy ty)) tys = go ty tys go _ _ = ([], orig_ty) -- Failure to match splitHsFunType other = ([], other) -------------------------------- -- | Retrieves the head of an HsAppsTy, if this can be done unambiguously, -- without consulting fixities. getAppsTyHead_maybe :: [LHsAppType name] -> Maybe (LHsType name, [LHsType name]) getAppsTyHead_maybe tys = case splitHsAppsTy tys of ([app1:apps], []) -> -- no symbols, some normal types Just (mkHsAppTys app1 apps, []) ([app1l:appsl, app1r:appsr], [L loc op]) -> -- one operator Just (L loc (HsTyVar (L loc op)), [mkHsAppTys app1l appsl, mkHsAppTys app1r appsr]) _ -> -- can't figure it out Nothing -- | Splits a [HsAppType name] (the payload of an HsAppsTy) into regions of prefix -- types (normal types) and infix operators. -- If @splitHsAppsTy tys = (non_syms, syms)@, then @tys@ starts with the first -- element of @non_syms@ followed by the first element of @syms@ followed by -- the next element of @non_syms@, etc. It is guaranteed that the non_syms list -- has one more element than the syms list. splitHsAppsTy :: [LHsAppType name] -> ([[LHsType name]], [Located name]) splitHsAppsTy = go [] [] [] where go acc acc_non acc_sym [] = (reverse (reverse acc : acc_non), reverse acc_sym) go acc acc_non acc_sym (L _ (HsAppPrefix ty) : rest) = go (ty : acc) acc_non acc_sym rest go acc acc_non acc_sym (L _ (HsAppInfix op) : rest) = go [] (reverse acc : acc_non) (op : acc_sym) rest -- Retrieve the name of the "head" of a nested type application -- somewhat like splitHsAppTys, but a little more thorough -- used to examine the result of a GADT-like datacon, so it doesn't handle -- *all* cases (like lists, tuples, (~), etc.) hsTyGetAppHead_maybe :: LHsType name -> Maybe (Located name, [LHsType name]) hsTyGetAppHead_maybe = go [] where go tys (L _ (HsTyVar ln)) = Just (ln, tys) go tys (L _ (HsAppsTy apps)) | Just (head, args) <- getAppsTyHead_maybe apps = go (args ++ tys) head go tys (L _ (HsAppTy l r)) = go (r : tys) l go tys (L _ (HsOpTy l (L loc n) r)) = Just (L loc n, l : r : tys) go tys (L _ (HsParTy t)) = go tys t go tys (L _ (HsKindSig t _)) = go tys t go _ _ = Nothing splitHsAppTys :: LHsType Name -> [LHsType Name] -> (LHsType Name, [LHsType Name]) -- no need to worry about HsAppsTy here splitHsAppTys (L _ (HsAppTy f a)) as = splitHsAppTys f (a:as) splitHsAppTys (L _ (HsParTy f)) as = splitHsAppTys f as splitHsAppTys f as = (f,as) -------------------------------- splitLHsPatSynTy :: LHsType name -> ( [LHsTyVarBndr name] , LHsContext name -- Required , LHsContext name -- Provided , LHsType name) -- Body splitLHsPatSynTy ty | L _ (HsQualTy { hst_ctxt = req, hst_body = ty2 }) <- ty1 , L _ (HsQualTy { hst_ctxt = prov, hst_body = ty3 }) <- ty2 = (tvs, req, prov, ty3) | L _ (HsQualTy { hst_ctxt = req, hst_body = ty2 }) <- ty1 = (tvs, req, noLoc [], ty2) | otherwise = (tvs, noLoc [], noLoc [], ty1) where (tvs, ty1) = splitLHsForAllTy ty splitLHsSigmaTy :: LHsType name -> ([LHsTyVarBndr name], LHsContext name, LHsType name) splitLHsSigmaTy ty | (tvs, ty1) <- splitLHsForAllTy ty , (ctxt, ty2) <- splitLHsQualTy ty1 = (tvs, ctxt, ty2) splitLHsForAllTy :: LHsType name -> ([LHsTyVarBndr name], LHsType name) splitLHsForAllTy (L _ (HsForAllTy { hst_bndrs = tvs, hst_body = body })) = (tvs, body) splitLHsForAllTy body = ([], body) splitLHsQualTy :: LHsType name -> (LHsContext name, LHsType name) splitLHsQualTy (L _ (HsQualTy { hst_ctxt = ctxt, hst_body = body })) = (ctxt, body) splitLHsQualTy body = (noLoc [], body) splitLHsInstDeclTy :: LHsSigType Name -> ([Name], LHsContext Name, LHsType Name) -- Split up an instance decl type, returning the pieces splitLHsInstDeclTy (HsIB { hsib_vars = itkvs , hsib_body = inst_ty }) | (tvs, cxt, body_ty) <- splitLHsSigmaTy inst_ty = (itkvs ++ map hsLTyVarName tvs, cxt, body_ty) -- Return implicitly bound type and kind vars -- For an instance decl, all of them are in scope where getLHsInstDeclHead :: LHsSigType name -> LHsType name getLHsInstDeclHead inst_ty | (_tvs, _cxt, body_ty) <- splitLHsSigmaTy (hsSigType inst_ty) = body_ty getLHsInstDeclClass_maybe :: LHsSigType name -> Maybe (Located name) -- Works on (HsSigType RdrName) getLHsInstDeclClass_maybe inst_ty = do { let head_ty = getLHsInstDeclHead inst_ty ; (cls, _) <- hsTyGetAppHead_maybe head_ty ; return cls } {- ************************************************************************ * * FieldOcc * * ************************************************************************ -} type LFieldOcc name = Located (FieldOcc name) -- | Represents an *occurrence* of an unambiguous field. We store -- both the 'RdrName' the user originally wrote, and after the -- renamer, the selector function. data FieldOcc name = FieldOcc { rdrNameFieldOcc :: Located RdrName -- ^ See Note [Located RdrNames] in HsExpr , selectorFieldOcc :: PostRn name name } deriving Typeable deriving instance Eq (PostRn name name) => Eq (FieldOcc name) deriving instance Ord (PostRn name name) => Ord (FieldOcc name) deriving instance (Data name, Data (PostRn name name)) => Data (FieldOcc name) instance Outputable (FieldOcc name) where ppr = ppr . rdrNameFieldOcc mkFieldOcc :: Located RdrName -> FieldOcc RdrName mkFieldOcc rdr = FieldOcc rdr PlaceHolder -- | Represents an *occurrence* of a field that is potentially -- ambiguous after the renamer, with the ambiguity resolved by the -- typechecker. We always store the 'RdrName' that the user -- originally wrote, and store the selector function after the renamer -- (for unambiguous occurrences) or the typechecker (for ambiguous -- occurrences). -- -- See Note [HsRecField and HsRecUpdField] in HsPat and -- Note [Disambiguating record fields] in TcExpr. -- See Note [Located RdrNames] in HsExpr data AmbiguousFieldOcc name = Unambiguous (Located RdrName) (PostRn name name) | Ambiguous (Located RdrName) (PostTc name name) deriving (Typeable) deriving instance ( Data name , Data (PostRn name name) , Data (PostTc name name)) => Data (AmbiguousFieldOcc name) instance Outputable (AmbiguousFieldOcc name) where ppr = ppr . rdrNameAmbiguousFieldOcc instance OutputableBndr (AmbiguousFieldOcc name) where pprInfixOcc = pprInfixOcc . rdrNameAmbiguousFieldOcc pprPrefixOcc = pprPrefixOcc . rdrNameAmbiguousFieldOcc mkAmbiguousFieldOcc :: Located RdrName -> AmbiguousFieldOcc RdrName mkAmbiguousFieldOcc rdr = Unambiguous rdr PlaceHolder rdrNameAmbiguousFieldOcc :: AmbiguousFieldOcc name -> RdrName rdrNameAmbiguousFieldOcc (Unambiguous (L _ rdr) _) = rdr rdrNameAmbiguousFieldOcc (Ambiguous (L _ rdr) _) = rdr selectorAmbiguousFieldOcc :: AmbiguousFieldOcc Id -> Id selectorAmbiguousFieldOcc (Unambiguous _ sel) = sel selectorAmbiguousFieldOcc (Ambiguous _ sel) = sel unambiguousFieldOcc :: AmbiguousFieldOcc Id -> FieldOcc Id unambiguousFieldOcc (Unambiguous rdr sel) = FieldOcc rdr sel unambiguousFieldOcc (Ambiguous rdr sel) = FieldOcc rdr sel ambiguousFieldOcc :: FieldOcc name -> AmbiguousFieldOcc name ambiguousFieldOcc (FieldOcc rdr sel) = Unambiguous rdr sel {- ************************************************************************ * * \subsection{Pretty printing} * * ************************************************************************ -} instance (OutputableBndr name) => Outputable (HsType name) where ppr ty = pprHsType ty instance Outputable HsTyLit where ppr = ppr_tylit instance (OutputableBndr name) => Outputable (LHsQTyVars name) where ppr (HsQTvs { hsq_explicit = tvs }) = interppSP tvs instance (OutputableBndr name) => Outputable (HsTyVarBndr name) where ppr (UserTyVar n) = ppr n ppr (KindedTyVar n k) = parens $ hsep [ppr n, dcolon, ppr k] instance (Outputable thing) => Outputable (HsImplicitBndrs name thing) where ppr (HsIB { hsib_body = ty }) = ppr ty instance (Outputable thing) => Outputable (HsWildCardBndrs name thing) where ppr (HsWC { hswc_body = ty }) = ppr ty instance Outputable (HsWildCardInfo name) where ppr (AnonWildCard _) = char '_' pprHsForAll :: OutputableBndr name => [LHsTyVarBndr name] -> LHsContext name -> SDoc pprHsForAll = pprHsForAllExtra Nothing -- | Version of 'pprHsForAll' that can also print an extra-constraints -- wildcard, e.g. @_ => a -> Bool@ or @(Show a, _) => a -> String@. This -- underscore will be printed when the 'Maybe SrcSpan' argument is a 'Just' -- containing the location of the extra-constraints wildcard. A special -- function for this is needed, as the extra-constraints wildcard is removed -- from the actual context and type, and stored in a separate field, thus just -- printing the type will not print the extra-constraints wildcard. pprHsForAllExtra :: OutputableBndr name => Maybe SrcSpan -> [LHsTyVarBndr name] -> LHsContext name -> SDoc pprHsForAllExtra extra qtvs cxt = pprHsForAllTvs qtvs <+> pprHsContextExtra show_extra (unLoc cxt) where show_extra = isJust extra pprHsForAllTvs :: OutputableBndr name => [LHsTyVarBndr name] -> SDoc pprHsForAllTvs qtvs | show_forall = forAllLit <+> interppSP qtvs <> dot | otherwise = empty where show_forall = opt_PprStyle_Debug || not (null qtvs) pprHsContext :: (OutputableBndr name) => HsContext name -> SDoc pprHsContext = maybe empty (<+> darrow) . pprHsContextMaybe pprHsContextNoArrow :: (OutputableBndr name) => HsContext name -> SDoc pprHsContextNoArrow = fromMaybe empty . pprHsContextMaybe pprHsContextMaybe :: (OutputableBndr name) => HsContext name -> Maybe SDoc pprHsContextMaybe [] = Nothing pprHsContextMaybe [L _ pred] = Just $ ppr_mono_ty FunPrec pred pprHsContextMaybe cxt = Just $ parens (interpp'SP cxt) -- True <=> print an extra-constraints wildcard, e.g. @(Show a, _) =>@ pprHsContextExtra :: (OutputableBndr name) => Bool -> HsContext name -> SDoc pprHsContextExtra show_extra ctxt | not show_extra = pprHsContext ctxt | null ctxt = char '_' <+> darrow | otherwise = parens (sep (punctuate comma ctxt')) <+> darrow where ctxt' = map ppr ctxt ++ [char '_'] pprConDeclFields :: OutputableBndr name => [LConDeclField name] -> SDoc pprConDeclFields fields = braces (sep (punctuate comma (map ppr_fld fields))) where ppr_fld (L _ (ConDeclField { cd_fld_names = ns, cd_fld_type = ty, cd_fld_doc = doc })) = ppr_names ns <+> dcolon <+> ppr ty <+> ppr_mbDoc doc ppr_names [n] = ppr n ppr_names ns = sep (punctuate comma (map ppr ns)) {- Note [Printing KindedTyVars] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Trac #3830 reminded me that we should really only print the kind signature on a KindedTyVar if the kind signature was put there by the programmer. During kind inference GHC now adds a PostTcKind to UserTyVars, rather than converting to KindedTyVars as before. (As it happens, the message in #3830 comes out a different way now, and the problem doesn't show up; but having the flag on a KindedTyVar seems like the Right Thing anyway.) -} -- Printing works more-or-less as for Types pprHsType, pprParendHsType :: (OutputableBndr name) => HsType name -> SDoc pprHsType ty = ppr_mono_ty TopPrec (prepare ty) pprParendHsType ty = ppr_mono_ty TyConPrec ty -- Before printing a type, remove outermost HsParTy parens prepare :: HsType name -> HsType name prepare (HsParTy ty) = prepare (unLoc ty) prepare (HsAppsTy [L _ (HsAppPrefix (L _ ty))]) = prepare ty prepare ty = ty ppr_mono_lty :: (OutputableBndr name) => TyPrec -> LHsType name -> SDoc ppr_mono_lty ctxt_prec ty = ppr_mono_ty ctxt_prec (unLoc ty) ppr_mono_ty :: (OutputableBndr name) => TyPrec -> HsType name -> SDoc ppr_mono_ty ctxt_prec (HsForAllTy { hst_bndrs = tvs, hst_body = ty }) = maybeParen ctxt_prec FunPrec $ sep [pprHsForAllTvs tvs, ppr_mono_lty TopPrec ty] ppr_mono_ty ctxt_prec (HsQualTy { hst_ctxt = L _ ctxt, hst_body = ty }) = maybeParen ctxt_prec FunPrec $ sep [pprHsContext ctxt, ppr_mono_lty TopPrec ty] ppr_mono_ty _ (HsBangTy b ty) = ppr b <> ppr_mono_lty TyConPrec ty ppr_mono_ty _ (HsRecTy flds) = pprConDeclFields flds ppr_mono_ty _ (HsTyVar (L _ name))= pprPrefixOcc name ppr_mono_ty prec (HsFunTy ty1 ty2) = ppr_fun_ty prec ty1 ty2 ppr_mono_ty _ (HsTupleTy con tys) = tupleParens std_con (pprWithCommas ppr tys) where std_con = case con of HsUnboxedTuple -> UnboxedTuple _ -> BoxedTuple ppr_mono_ty _ (HsKindSig ty kind) = parens (ppr_mono_lty TopPrec ty <+> dcolon <+> ppr kind) ppr_mono_ty _ (HsListTy ty) = brackets (ppr_mono_lty TopPrec ty) ppr_mono_ty _ (HsPArrTy ty) = paBrackets (ppr_mono_lty TopPrec ty) ppr_mono_ty prec (HsIParamTy n ty) = maybeParen prec FunPrec (ppr n <+> dcolon <+> ppr_mono_lty TopPrec ty) ppr_mono_ty _ (HsSpliceTy s _) = pprSplice s ppr_mono_ty _ (HsCoreTy ty) = ppr ty ppr_mono_ty _ (HsExplicitListTy _ tys) = quote $ brackets (interpp'SP tys) ppr_mono_ty _ (HsExplicitTupleTy _ tys) = quote $ parens (interpp'SP tys) ppr_mono_ty _ (HsTyLit t) = ppr_tylit t ppr_mono_ty _ (HsWildCardTy (AnonWildCard _)) = char '_' ppr_mono_ty ctxt_prec (HsEqTy ty1 ty2) = maybeParen ctxt_prec TyOpPrec $ ppr_mono_lty TyOpPrec ty1 <+> char '~' <+> ppr_mono_lty TyOpPrec ty2 ppr_mono_ty ctxt_prec (HsAppsTy tys) = maybeParen ctxt_prec TyConPrec $ hsep (map (ppr_app_ty TopPrec . unLoc) tys) ppr_mono_ty ctxt_prec (HsAppTy fun_ty arg_ty) = maybeParen ctxt_prec TyConPrec $ hsep [ppr_mono_lty FunPrec fun_ty, ppr_mono_lty TyConPrec arg_ty] ppr_mono_ty ctxt_prec (HsOpTy ty1 (L _ op) ty2) = maybeParen ctxt_prec TyOpPrec $ sep [ ppr_mono_lty TyOpPrec ty1 , sep [pprInfixOcc op, ppr_mono_lty TyOpPrec ty2 ] ] ppr_mono_ty _ (HsParTy ty) = parens (ppr_mono_lty TopPrec ty) -- Put the parens in where the user did -- But we still use the precedence stuff to add parens because -- toHsType doesn't put in any HsParTys, so we may still need them ppr_mono_ty ctxt_prec (HsDocTy ty doc) = maybeParen ctxt_prec TyOpPrec $ ppr_mono_lty TyOpPrec ty <+> ppr (unLoc doc) -- we pretty print Haddock comments on types as if they were -- postfix operators -------------------------- ppr_fun_ty :: (OutputableBndr name) => TyPrec -> LHsType name -> LHsType name -> SDoc ppr_fun_ty ctxt_prec ty1 ty2 = let p1 = ppr_mono_lty FunPrec ty1 p2 = ppr_mono_lty TopPrec ty2 in maybeParen ctxt_prec FunPrec $ sep [p1, text "->" <+> p2] -------------------------- ppr_app_ty :: OutputableBndr name => TyPrec -> HsAppType name -> SDoc ppr_app_ty _ (HsAppInfix (L _ n)) = pprInfixOcc n ppr_app_ty _ (HsAppPrefix (L _ (HsTyVar (L _ n)))) = pprPrefixOcc n ppr_app_ty ctxt (HsAppPrefix ty) = ppr_mono_lty ctxt ty -------------------------- ppr_tylit :: HsTyLit -> SDoc ppr_tylit (HsNumTy _ i) = integer i ppr_tylit (HsStrTy _ s) = text (show s)