% (c) The GRASP Project, Glasgow University, 1992-2002
%
\begin{code}
-{-# OPTIONS -w #-}
--- The above warning supression flag is a temporary kludge.
--- While working on this module you are encouraged to remove it and fix
--- any warnings in the module. See
--- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
--- for details
-
module TcRnTypes(
TcRnIf, TcRn, TcM, RnM, IfM, IfL, IfG, -- The monad is opaque outside this module
TcRef,
IfGblEnv(..), IfLclEnv(..),
-- Ranamer types
- ErrCtxt, RecFieldEnv,
+ ErrCtxt, RecFieldEnv(..),
ImportAvails(..), emptyImportAvails, plusImportAvails,
WhereFrom(..), mkModDeps,
TcTyThing(..), pprTcTyThingCategory, RefinementVisibility(..),
-- Template Haskell
- ThStage(..), topStage, topSpliceStage,
- ThLevel, impLevel, topLevel,
+ ThStage(..), topStage, topAnnStage, topSpliceStage,
+ ThLevel, impLevel, outerLevel, thLevel,
-- Arrows
ArrowCtxt(NoArrowCtxt), newArrowScope, escapeArrowScope,
-- Insts
- Inst(..), InstOrigin(..), InstLoc(..),
- pprInstLoc, pprInstArising, instLocSpan, instLocOrigin,
+ Inst(..), EqInstCo, InstOrigin(..), InstLoc(..),
+ pprInstLoc, pprInstArising, instLocSpan, instLocOrigin, setInstLoc,
LIE, emptyLIE, unitLIE, plusLIE, consLIE, instLoc, instSpan,
plusLIEs, mkLIE, isEmptyLIE, lieToList, listToLIE,
-- Misc other types
- TcId, TcIdSet, TcDictBinds,
+ TcId, TcIdSet, TcDictBinds, TcTyVarBind(..), TcTyVarBinds
) where
import HsSyn hiding (LIE)
import HscTypes
-import Packages
import Type
import Coercion
import TcType
+import Annotations
import InstEnv
import FamInstEnv
import IOEnv
import Bag
import Outputable
import ListSetOps
-import FiniteMap
import FastString
-import Data.Maybe
-import Data.List
+import Data.Set (Set)
\end{code}
type TcM a = TcRn a -- Historical
\end{code}
+Representation of type bindings to uninstantiated meta variables used during
+constraint solving.
+
+\begin{code}
+data TcTyVarBind = TcTyVarBind TcTyVar TcType
+
+type TcTyVarBinds = Bag TcTyVarBind
+
+instance Outputable TcTyVarBind where
+ ppr (TcTyVarBind tv ty) = ppr tv <+> text ":=" <+> ppr ty
+\end{code}
+
%************************************************************************
%* *
data TcGblEnv
= TcGblEnv {
- tcg_mod :: Module, -- Module being compiled
- tcg_src :: HscSource, -- What kind of module
- -- (regular Haskell, hs-boot, ext-core)
+ tcg_mod :: Module, -- ^ Module being compiled
+ tcg_src :: HscSource,
+ -- ^ What kind of module (regular Haskell, hs-boot, ext-core)
- tcg_rdr_env :: GlobalRdrEnv, -- Top level envt; used during renaming
- tcg_default :: Maybe [Type], -- Types used for defaulting
- -- Nothing => no 'default' decl
+ tcg_rdr_env :: GlobalRdrEnv, -- ^ Top level envt; used during renaming
+ tcg_default :: Maybe [Type],
+ -- ^ Types used for defaulting. @Nothing@ => no @default@ decl
- tcg_fix_env :: FixityEnv, -- Just for things in this module
- tcg_field_env :: RecFieldEnv, -- Just for things in this module
+ tcg_fix_env :: FixityEnv, -- ^ Just for things in this module
+ tcg_field_env :: RecFieldEnv, -- ^ Just for things in this module
- tcg_type_env :: TypeEnv, -- Global type env for the module we are compiling now
- -- All TyCons and Classes (for this module) end up in here right away,
- -- along with their derived constructors, selectors.
- --
- -- (Ids defined in this module start in the local envt,
- -- though they move to the global envt during zonking)
+ tcg_type_env :: TypeEnv,
+ -- ^ Global type env for the module we are compiling now. All
+ -- TyCons and Classes (for this module) end up in here right away,
+ -- along with their derived constructors, selectors.
+ --
+ -- (Ids defined in this module start in the local envt, though they
+ -- move to the global envt during zonking)
tcg_type_env_var :: TcRef TypeEnv,
-- Used only to initialise the interface-file
-- bound in this module when dealing with hi-boot recursions
-- Updated at intervals (e.g. after dealing with types and classes)
- tcg_inst_env :: InstEnv, -- Instance envt for *home-package*
- -- modules; Includes the dfuns in
- -- tcg_insts
- tcg_fam_inst_env :: FamInstEnv, -- Ditto for family instances
+ tcg_inst_env :: InstEnv,
+ -- ^ Instance envt for /home-package/ modules; Includes the dfuns in
+ -- tcg_insts
+ tcg_fam_inst_env :: FamInstEnv, -- ^ Ditto for family instances
-- Now a bunch of things about this module that are simply
-- accumulated, but never consulted until the end.
-- Nevertheless, it's convenient to accumulate them along
-- with the rest of the info from this module.
- tcg_exports :: [AvailInfo], -- What is exported
- tcg_imports :: ImportAvails, -- Information about what was imported
- -- from where, including things bound
- -- in this module
-
- tcg_dus :: DefUses, -- What is defined in this module and what is used.
- -- The latter is used to generate
- -- (a) version tracking; no need to recompile if these
- -- things have not changed version stamp
- -- (b) unused-import info
-
- tcg_keep :: TcRef NameSet, -- Locally-defined top-level names to keep alive
- -- "Keep alive" means give them an Exported flag, so
- -- that the simplifier does not discard them as dead
- -- code, and so that they are exposed in the interface file
- -- (but not to export to the user).
- --
- -- Some things, like dict-fun Ids and default-method Ids are
- -- "born" with the Exported flag on, for exactly the above reason,
- -- but some we only discover as we go. Specifically:
- -- * The to/from functions for generic data types
- -- * Top-level variables appearing free in the RHS of an orphan rule
- -- * Top-level variables appearing free in a TH bracket
-
- tcg_inst_uses :: TcRef NameSet, -- Home-package Dfuns actually used
- -- Used to generate version dependencies
- -- This records usages, rather like tcg_dus, but it has to
- -- be a mutable variable so it can be augmented
- -- when we look up an instance. These uses of dfuns are
- -- rather like the free variables of the program, but
- -- are implicit instead of explicit.
-
- tcg_th_used :: TcRef Bool, -- True <=> Template Haskell syntax used
- -- We need this so that we can generate a dependency on the
- -- Template Haskell package, becuase the desugarer is going to
- -- emit loads of references to TH symbols. It's rather like
- -- tcg_inst_uses; the reference is implicit rather than explicit,
- -- so we have to zap a mutable variable.
-
- tcg_dfun_n :: TcRef Int, -- Allows us to number off the names of DFuns
- -- It's convenient to allocate an External Name for a DFun, with
- -- a permanently-fixed unique, just like other top-level functions
- -- defined in this module. But that means we need a canonical
- -- occurrence name, distinct from all other dfuns in this module,
- -- and this name supply serves that purpose (df1, df2, etc).
-
- -- The next fields accumulate the payload of the module
- -- The binds, rules and foreign-decl fiels are collected
- -- initially in un-zonked form and are finally zonked in tcRnSrcDecls
-
- -- The next fields accumulate the payload of the
- -- module The binds, rules and foreign-decl fiels are
- -- collected initially in un-zonked form and are
- -- finally zonked in tcRnSrcDecls
-
- tcg_rn_imports :: Maybe [LImportDecl Name],
+ tcg_exports :: [AvailInfo], -- ^ What is exported
+ tcg_imports :: ImportAvails,
+ -- ^ Information about what was imported from where, including
+ -- things bound in this module.
+
+ tcg_dus :: DefUses,
+ -- ^ What is defined in this module and what is used.
+ -- The latter is used to generate
+ --
+ -- (a) version tracking; no need to recompile if these things have
+ -- not changed version stamp
+ --
+ -- (b) unused-import info
+
+ tcg_keep :: TcRef NameSet,
+ -- ^ Locally-defined top-level names to keep alive.
+ --
+ -- "Keep alive" means give them an Exported flag, so that the
+ -- simplifier does not discard them as dead code, and so that they
+ -- are exposed in the interface file (but not to export to the
+ -- user).
+ --
+ -- Some things, like dict-fun Ids and default-method Ids are "born"
+ -- with the Exported flag on, for exactly the above reason, but some
+ -- we only discover as we go. Specifically:
+ --
+ -- * The to/from functions for generic data types
+ --
+ -- * Top-level variables appearing free in the RHS of an orphan
+ -- rule
+ --
+ -- * Top-level variables appearing free in a TH bracket
+
+ tcg_inst_uses :: TcRef NameSet,
+ -- ^ Home-package Dfuns actually used.
+ --
+ -- Used to generate version dependencies This records usages, rather
+ -- like tcg_dus, but it has to be a mutable variable so it can be
+ -- augmented when we look up an instance. These uses of dfuns are
+ -- rather like the free variables of the program, but are implicit
+ -- instead of explicit.
+
+ tcg_th_used :: TcRef Bool,
+ -- ^ @True@ <=> Template Haskell syntax used.
+ --
+ -- We need this so that we can generate a dependency on the Template
+ -- Haskell package, becuase the desugarer is going to emit loads of
+ -- references to TH symbols. It's rather like tcg_inst_uses; the
+ -- reference is implicit rather than explicit, so we have to zap a
+ -- mutable variable.
+
+ tcg_dfun_n :: TcRef OccSet,
+ -- ^ Allows us to choose unique DFun names.
+
+ -- The next fields accumulate the payload of the module
+ -- The binds, rules and foreign-decl fiels are collected
+ -- initially in un-zonked form and are finally zonked in tcRnSrcDecls
+
tcg_rn_exports :: Maybe [Located (IE Name)],
- tcg_rn_decls :: Maybe (HsGroup Name), -- renamed decls, maybe
- -- Nothing <=> Don't retain renamed decls
+ tcg_rn_imports :: [LImportDecl Name],
+ -- Keep the renamed imports regardless. They are not
+ -- voluminous and are needed if you want to report unused imports
+
+ tcg_used_rdrnames :: TcRef (Set RdrName),
+ -- The set of used *imported* (not locally-defined) RdrNames
+ -- Used only to report unused import declarations
+
+ tcg_rn_decls :: Maybe (HsGroup Name),
+ -- ^ Renamed decls, maybe. @Nothing@ <=> Don't retain renamed
+ -- decls.
tcg_binds :: LHsBinds Id, -- Value bindings in this module
- tcg_deprecs :: Deprecations, -- ...Deprecations
+ tcg_warns :: Warnings, -- ...Warnings and deprecations
+ tcg_anns :: [Annotation], -- ...Annotations
tcg_insts :: [Instance], -- ...Instances
tcg_fam_insts :: [FamInst], -- ...Family instances
tcg_rules :: [LRuleDecl Id], -- ...Rules
tcg_fords :: [LForeignDecl Id], -- ...Foreign import & exports
- tcg_doc :: Maybe (HsDoc Name), -- Maybe Haddock documentation
- tcg_hmi :: HaddockModInfo Name, -- Haddock module information
- tcg_hpc :: AnyHpcUsage -- True if any part of the prog uses hpc instrumentation.
+ tcg_doc_hdr :: Maybe LHsDocString, -- ^ Maybe Haddock header docs
+ tcg_hpc :: AnyHpcUsage, -- ^ @True@ if any part of the
+ -- prog uses hpc instrumentation.
+
+ tcg_main :: Maybe Name -- ^ The Name of the main
+ -- function, if this module is
+ -- the main module.
}
-type RecFieldEnv = NameEnv [Name] -- Maps a constructor name *in this module*
- -- to the fields for that constructor
+data RecFieldEnv
+ = RecFields (NameEnv [Name]) -- Maps a constructor name *in this module*
+ -- to the fields for that constructor
+ NameSet -- Set of all fields declared *in this module*;
+ -- used to suppress name-shadowing complaints
+ -- when using record wild cards
+ -- E.g. let fld = e in C {..}
-- This is used when dealing with ".." notation in record
-- construction and pattern matching.
- -- The FieldEnv deals *only* with constructors defined in
- -- *thie* module. For imported modules, we get the same info
- -- from the TypeEnv
+ -- The FieldEnv deals *only* with constructors defined in *this*
+ -- module. For imported modules, we get the same info from the
+ -- TypeEnv
\end{code}
%************************************************************************
-- Discarded after typecheck/rename; not passed on to desugarer
= TcLclEnv {
tcl_loc :: SrcSpan, -- Source span
- tcl_ctxt :: ErrCtxt, -- Error context
+ tcl_ctxt :: [ErrCtxt], -- Error context, innermost on top
tcl_errs :: TcRef Messages, -- Place to accumulate errors
tcl_th_ctxt :: ThStage, -- Template Haskell context
-- We still need the unsullied global name env so that
-- we can look up record field names
- tcl_env :: NameEnv TcTyThing, -- The local type environment: Ids and TyVars
- -- defined in this module
+ tcl_env :: NameEnv TcTyThing, -- The local type environment: Ids and
+ -- TyVars defined in this module
tcl_tyvars :: TcRef TcTyVarSet, -- The "global tyvars"
-- Namely, the in-scope TyVars bound in tcl_env,
- -- plus the tyvars mentioned in the types of Ids bound in tcl_lenv
- -- Why mutable? see notes with tcGetGlobalTyVars
+ -- plus the tyvars mentioned in the types of Ids bound
+ -- in tcl_lenv.
+ -- Why mutable? see notes with tcGetGlobalTyVars
+
+ tcl_lie :: TcRef LIE, -- Place to accumulate type constraints
- tcl_lie :: TcRef LIE -- Place to accumulate type constraints
+ tcl_tybinds :: TcRef TcTyVarBinds -- Meta and coercion type variable
+ -- bindings accumulated during
+ -- constraint solving
}
-}
---------------------------
--- Template Haskell levels
+-- Template Haskell stages and levels
---------------------------
+data ThStage -- See Note [Template Haskell state diagram] in TcSplice
+ = Splice -- Top-level splicing
+ -- This code will be run *at compile time*;
+ -- the result replaces the splice
+ -- Binding level = 0
+
+ | Comp -- Ordinary Haskell code
+ -- Binding level = 1
+
+ | Brack -- Inside brackets
+ ThStage -- Binding level = level(stage) + 1
+ (TcRef [PendingSplice]) -- Accumulate pending splices here
+ (TcRef LIE) -- and type constraints here
+
+topStage, topAnnStage, topSpliceStage :: ThStage
+topStage = Comp
+topAnnStage = Splice
+topSpliceStage = Splice
+
+instance Outputable ThStage where
+ ppr Splice = text "Splice"
+ ppr Comp = text "Comp"
+ ppr (Brack s _ _) = text "Brack" <> parens (ppr s)
+
type ThLevel = Int
- -- Indicates how many levels of brackets we are inside
- -- (always >= 0)
+ -- See Note [Template Haskell levels] in TcSplice
-- Incremented when going inside a bracket,
-- decremented when going inside a splice
-- NB: ThLevel is one greater than the 'n' in Fig 2 of the
-- original "Template meta-programming for Haskell" paper
-impLevel, topLevel :: ThLevel
-topLevel = 1 -- Things defined at top level of this module
+impLevel, outerLevel :: ThLevel
impLevel = 0 -- Imported things; they can be used inside a top level splice
+outerLevel = 1 -- Things defined outside brackets
+-- NB: Things at level 0 are not *necessarily* imported.
+-- eg $( \b -> ... ) here b is bound at level 0
--
-- For example:
-- f = ...
-- g1 = $(map ...) is OK
-- g2 = $(f ...) is not OK; because we havn't compiled f yet
-
-data ThStage
- = Comp -- Ordinary compiling, at level topLevel
- | Splice ThLevel -- Inside a splice
- | Brack ThLevel -- Inside brackets;
- (TcRef [PendingSplice]) -- accumulate pending splices here
- (TcRef LIE) -- and type constraints here
-topStage, topSpliceStage :: ThStage
-topStage = Comp
-topSpliceStage = Splice (topLevel - 1) -- Stage for the body of a top-level splice
+thLevel :: ThStage -> ThLevel
+thLevel Splice = 0
+thLevel Comp = 1
+thLevel (Brack s _ _) = thLevel s + 1
---------------------------
-- Arrow-notation context
\end{code}
\begin{code}
-type ErrCtxt = [TidyEnv -> TcM (TidyEnv, Message)]
- -- Innermost first. Monadic so that we have a chance
- -- to deal with bound type variables just before error
- -- message construction
+type ErrCtxt = (Bool, TidyEnv -> TcM (TidyEnv, Message))
+ -- Monadic so that we have a chance
+ -- to deal with bound type variables just before error
+ -- message construction
+
+ -- Bool: True <=> this is a landmark context; do not
+ -- discard it when trimming for display
\end{code}
%* *
%************************************************************************
-ImportAvails summarises what was imported from where, irrespective
-of whether the imported things are actually used or not
-It is used * when processing the export list
- * when constructing usage info for the inteface file
- * to identify the list of directly imported modules
- for initialisation purposes and
- for optimsed overlap checking of family instances
- * when figuring out what things are really unused
-
\begin{code}
+-- | 'ImportAvails' summarises what was imported from where, irrespective of
+-- whether the imported things are actually used or not. It is used:
+--
+-- * when processing the export list,
+--
+-- * when constructing usage info for the interface file,
+--
+-- * to identify the list of directly imported modules for initialisation
+-- purposes and for optimised overlap checking of family instances,
+--
+-- * when figuring out what things are really unused
+--
data ImportAvails
= ImportAvails {
- imp_mods :: ModuleEnv (Module, [(ModuleName, Bool, SrcSpan)]),
- -- Domain is all directly-imported modules
- -- The ModuleName is what the module was imported as, e.g. in
- -- import Foo as Bar
- -- it is Bar.
- -- Bool means:
- -- True => import was "import Foo ()"
- -- False => import was some other form
- --
- -- We need the Module in the range because we can't get
- -- the keys of a ModuleEnv
- -- Used
- -- (a) to help construct the usage information in
- -- the interface file; if we import somethign we
- -- need to recompile if the export version changes
- -- (b) to specify what child modules to initialise
- --
- -- We need a full ModuleEnv rather than a ModuleNameEnv
- -- here, because we might be importing modules of the
- -- same name from different packages. (currently not the case,
- -- but might be in the future).
+ imp_mods :: ModuleEnv [(ModuleName, Bool, SrcSpan)],
+ -- ^ Domain is all directly-imported modules
+ -- The 'ModuleName' is what the module was imported as, e.g. in
+ -- @
+ -- import Foo as Bar
+ -- @
+ -- it is @Bar@.
+ --
+ -- The 'Bool' means:
+ --
+ -- - @True@ => import was @import Foo ()@
+ --
+ -- - @False@ => import was some other form
+ --
+ -- Used
+ --
+ -- (a) to help construct the usage information in the interface
+ -- file; if we import somethign we need to recompile if the
+ -- export version changes
+ --
+ -- (b) to specify what child modules to initialise
+ --
+ -- We need a full ModuleEnv rather than a ModuleNameEnv here,
+ -- because we might be importing modules of the same name from
+ -- different packages. (currently not the case, but might be in the
+ -- future).
imp_dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface),
- -- Home-package modules needed by the module being compiled
- --
- -- It doesn't matter whether any of these dependencies
- -- are actually *used* when compiling the module; they
- -- are listed if they are below it at all. For
- -- example, suppose M imports A which imports X. Then
- -- compiling M might not need to consult X.hi, but X
- -- is still listed in M's dependencies.
+ -- ^ Home-package modules needed by the module being compiled
+ --
+ -- It doesn't matter whether any of these dependencies
+ -- are actually /used/ when compiling the module; they
+ -- are listed if they are below it at all. For
+ -- example, suppose M imports A which imports X. Then
+ -- compiling M might not need to consult X.hi, but X
+ -- is still listed in M's dependencies.
imp_dep_pkgs :: [PackageId],
- -- Packages needed by the module being compiled, whether
- -- directly, or via other modules in this package, or via
- -- modules imported from other packages.
+ -- ^ Packages needed by the module being compiled, whether directly,
+ -- or via other modules in this package, or via modules imported
+ -- from other packages.
imp_orphs :: [Module],
- -- Orphan modules below us in the import tree (and maybe
- -- including us for imported modules)
+ -- ^ Orphan modules below us in the import tree (and maybe including
+ -- us for imported modules)
imp_finsts :: [Module]
- -- Family instance modules below us in the import tree (and
- -- maybe including us for imported modules)
+ -- ^ Family instance modules below us in the import tree (and maybe
+ -- including us for imported modules)
}
mkModDeps :: [(ModuleName, IsBootInterface)]
(ImportAvails { imp_mods = mods2,
imp_dep_mods = dmods2, imp_dep_pkgs = dpkgs2,
imp_orphs = orphs2, imp_finsts = finsts2 })
- = ImportAvails { imp_mods = plusModuleEnv_C plus_mod mods1 mods2,
+ = ImportAvails { imp_mods = plusModuleEnv_C (++) mods1 mods2,
imp_dep_mods = plusUFM_C plus_mod_dep dmods1 dmods2,
imp_dep_pkgs = dpkgs1 `unionLists` dpkgs2,
imp_orphs = orphs1 `unionLists` orphs2,
imp_finsts = finsts1 `unionLists` finsts2 }
where
- plus_mod (m1, xs1) (_, xs2) = (m1, xs1 ++ xs2)
plus_mod_dep (m1, boot1) (m2, boot2)
= WARN( not (m1 == m2), (ppr m1 <+> ppr m2) $$ (ppr boot1 <+> ppr boot2) )
-- Check mod-names match
data Inst
= Dict {
tci_name :: Name,
- tci_pred :: TcPredType,
+ tci_pred :: TcPredType, -- Class or implicit parameter only
tci_loc :: InstLoc
}
-- co :: ty1 ~ ty2
tci_left :: TcType, -- ty1 -- both types are...
tci_right :: TcType, -- ty2 -- ...free of boxes
- tci_co :: Either -- co
- TcTyVar -- - a wanted equation, with a hole, to be
- -- filled with a witness for the equality;
- -- for equation arising from deferring
- -- unification, 'ty1' is the actual and
- -- 'ty2' the expected type
- Coercion, -- - a given equation, with a coercion
- -- witnessing the equality;
- -- a coercion that originates from a
- -- signature or a GADT is a CoVar, but
- -- after normalisation of coercions, they
- -- can be arbitrary Coercions involving
- -- constructors and pseudo-constructors
- -- like sym and trans.
+ tci_co :: EqInstCo, -- co
tci_loc :: InstLoc,
tci_name :: Name -- Debugging help only: this makes it easier to
-- follow where a constraint is used in a morass
- -- of trace messages! Unlike other Insts, it has
- -- no semantic significance whatsoever.
+ -- of trace messages! Unlike other Insts, it
+ -- has no semantic significance whatsoever.
}
+
+type EqInstCo = Either -- Distinguish between given and wanted coercions
+ TcTyVar -- - a wanted equation, with a hole, to be filled
+ -- with a witness for the equality; for equation
+ -- arising from deferring unification, 'ty1' is
+ -- the actual and 'ty2' the expected type
+ Coercion -- - a given equation, with a coercion witnessing
+ -- the equality; a coercion that originates
+ -- from a signature or a GADT is a CoVar, but
+ -- after normalisation of coercions, they can
+ -- be arbitrary Coercions involving constructors
+ -- and pseudo-constructors like sym and trans.
\end{code}
@Insts@ are ordered by their class/type info, rather than by their
\begin{code}
instance Ord Inst where
- compare = cmpInst
+ compare = cmpInst
+ -- Used *only* for AvailEnv in TcSimplify
instance Eq Inst where
(==) i1 i2 = case i1 `cmpInst` i2 of
- EQ -> True
- other -> False
+ EQ -> True
+ _ -> False
+cmpInst :: Inst -> Inst -> Ordering
cmpInst d1@(Dict {}) d2@(Dict {}) = tci_pred d1 `tcCmpPred` tci_pred d2
-cmpInst (Dict {}) other = LT
+cmpInst (Dict {}) _ = LT
cmpInst (Method {}) (Dict {}) = GT
cmpInst m1@(Method {}) m2@(Method {}) = (tci_oid m1 `compare` tci_oid m2) `thenCmp`
(tci_tys m1 `tcCmpTypes` tci_tys m2)
-cmpInst (Method {}) other = LT
+cmpInst (Method {}) _ = LT
cmpInst (LitInst {}) (Dict {}) = GT
cmpInst (LitInst {}) (Method {}) = GT
cmpInst l1@(LitInst {}) l2@(LitInst {}) = (tci_lit l1 `compare` tci_lit l2) `thenCmp`
(tci_ty l1 `tcCmpType` tci_ty l2)
-cmpInst (LitInst {}) other = LT
+cmpInst (LitInst {}) _ = LT
-- Implication constraints are compared by *name*
-- not by type; that is, we make no attempt to do CSE on them
cmpInst (ImplicInst {}) (Method {}) = GT
cmpInst (ImplicInst {}) (LitInst {}) = GT
cmpInst i1@(ImplicInst {}) i2@(ImplicInst {}) = tci_name i1 `compare` tci_name i2
-cmpInst (ImplicInst {}) other = LT
+cmpInst (ImplicInst {}) _ = LT
-- same for Equality constraints
-cmpInst (EqInst {}) (Dict {}) = GT
-cmpInst (EqInst {}) (Method {}) = GT
-cmpInst (EqInst {}) (LitInst {}) = GT
-cmpInst (EqInst {}) (ImplicInst {}) = GT
-cmpInst i1@(EqInst {}) i2@(EqInst {}) = tci_name i1 `compare` tci_name i2
+cmpInst (EqInst {}) (Dict {}) = GT
+cmpInst (EqInst {}) (Method {}) = GT
+cmpInst (EqInst {}) (LitInst {}) = GT
+cmpInst (EqInst {}) (ImplicInst {}) = GT
+cmpInst i1@(EqInst {}) i2@(EqInst {}) = (tci_left i1 `tcCmpType` tci_left i2) `thenCmp`
+ (tci_right i1 `tcCmpType` tci_right i2)
\end{code}
-- FIXME: Rename this. It clashes with (Located (IE ...))
type LIE = Bag Inst
-isEmptyLIE = isEmptyBag
-emptyLIE = emptyBag
-unitLIE inst = unitBag inst
-mkLIE insts = listToBag insts
+isEmptyLIE :: LIE -> Bool
+isEmptyLIE = isEmptyBag
+
+emptyLIE :: LIE
+emptyLIE = emptyBag
+
+unitLIE :: Inst -> LIE
+unitLIE inst = unitBag inst
+
+mkLIE :: [Inst] -> LIE
+mkLIE insts = listToBag insts
+
+plusLIE :: LIE -> LIE -> LIE
plusLIE lie1 lie2 = lie1 `unionBags` lie2
-plusLIEs lies = unionManyBags lies
-lieToList = bagToList
-listToLIE = listToBag
+plusLIEs :: [LIE] -> LIE
+plusLIEs lies = unionManyBags lies
+
+lieToList :: LIE -> [Inst]
+lieToList = bagToList
+
+listToLIE :: [Inst] -> LIE
+listToLIE = listToBag
+
+consLIE :: Inst -> LIE -> LIE
consLIE inst lie = lie `snocBag` inst
-- Putting the new Inst at the *end* of the bag is a half-hearted attempt
-- to ensure that we tend to report the *leftmost* type-constraint error
\begin{code}
-------------------------------------------
-data InstLoc = InstLoc InstOrigin SrcSpan ErrCtxt
+data InstLoc = InstLoc InstOrigin SrcSpan [ErrCtxt]
instLoc :: Inst -> InstLoc
instLoc inst = tci_loc inst
+setInstLoc :: Inst -> InstLoc -> Inst
+setInstLoc inst new_loc = inst { tci_loc = new_loc }
+
instSpan :: Inst -> SrcSpan
instSpan wanted = instLocSpan (instLoc wanted)
| ExprSigOrigin -- e :: ty
| RecordUpdOrigin
| ViewPatOrigin
+
| InstScOrigin -- Typechecking superclasses of an instance declaration
+
+ | NoScOrigin -- A very special hack; see TcSimplify,
+ -- Note [Recursive instances and superclases]
+
+
| DerivOrigin -- Typechecking deriving
| StandAloneDerivOrigin -- Typechecking stand-alone deriving
| DefaultOrigin -- Typechecking a default decl
| ProcOrigin -- Arising from a proc expression
| ImplicOrigin SDoc -- An implication constraint
| EqOrigin -- A type equality
+ | AnnOrigin -- An annotation
instance Outputable InstOrigin where
ppr (OccurrenceOf name) = hsep [ptext (sLit "a use of"), quotes (ppr name)]
ppr TupleOrigin = ptext (sLit "a tuple")
ppr NegateOrigin = ptext (sLit "a use of syntactic negation")
ppr InstScOrigin = ptext (sLit "the superclasses of an instance declaration")
+ ppr NoScOrigin = ptext (sLit "an instance declaration")
ppr DerivOrigin = ptext (sLit "the 'deriving' clause of a data type declaration")
ppr StandAloneDerivOrigin = ptext (sLit "a 'deriving' declaration")
ppr DefaultOrigin = ptext (sLit "a 'default' declaration")
ppr (ImplicOrigin doc) = doc
ppr (SigOrigin info) = pprSkolInfo info
ppr EqOrigin = ptext (sLit "a type equality")
+ ppr InstSigOrigin = panic "ppr InstSigOrigin"
+ ppr AnnOrigin = ptext (sLit "an annotation")
\end{code}
projects / ghc-hetmet.git / blobdiff