tcLookupLocatedGlobal, tcLookupGlobal,
tcLookupField, tcLookupTyCon, tcLookupClass, tcLookupDataCon,
tcLookupLocatedGlobalId, tcLookupLocatedTyCon,
- tcLookupLocatedClass,
+ tcLookupLocatedClass, tcLookupFamInst,
-- Local environment
tcExtendKindEnv, tcExtendKindEnvTvs,
tcExtendTyVarEnv, tcExtendTyVarEnv2,
+ tcExtendGhciEnv,
tcExtendIdEnv, tcExtendIdEnv1, tcExtendIdEnv2,
tcLookup, tcLookupLocated, tcLookupLocalIds,
tcLookupId, tcLookupTyVar, getScopedTyVarBinds,
topIdLvl,
-- New Ids
- newLocalName, newDFunName, newFamInstTyConName
+ newLocalName, newDFunName, newFamInstTyConName,
+
+ -- Errors
+ famInstNotFound
) where
#include "HsVersions.h"
import TcType
import TcGadt
import qualified Type
-import Id
import Var
import VarSet
import VarEnv
import RdrName
import InstEnv
+import FamInstEnv
import DataCon
import TyCon
import Class
tcLookupLocatedTyCon :: Located Name -> TcM TyCon
tcLookupLocatedTyCon = addLocM tcLookupTyCon
+
+-- Look up the representation tycon of a family instance.
+--
+-- The match must be unique - ie, match exactly one instance - but the
+-- type arguments used for matching may be more specific than those of
+-- the family instance declaration.
+--
+-- Return the instance tycon and its type instance. For example, if we have
+--
+-- tcLookupFamInst 'T' '[Int]' yields (':R42T', 'Int')
+--
+-- then we have a coercion (ie, type instance of family instance coercion)
+--
+-- :Co:R42T Int :: T [Int] ~ :R42T Int
+--
+-- which implies that :R42T was declared as 'data instance T [a]'.
+--
+tcLookupFamInst :: TyCon -> [Type] -> TcM (TyCon, [Type])
+tcLookupFamInst tycon tys
+ | not (isOpenTyCon tycon)
+ = return (tycon, tys)
+ | otherwise
+ = do { env <- getGblEnv
+ ; eps <- getEps
+ ; let instEnv = (eps_fam_inst_env eps, tcg_fam_inst_env env)
+ ; case lookupFamInstEnv instEnv tycon tys of
+ [(fam_inst, rep_tys)] -> return (famInstTyCon fam_inst, rep_tys)
+ other -> famInstNotFound tycon tys other
+ }
\end{code}
%************************************************************************
\begin{code}
tcExtendIdEnv :: [TcId] -> TcM a -> TcM a
--- Invariant: the TcIds are fully zonked. Reasons:
--- (a) The kinds of the forall'd type variables are defaulted
--- (see Kind.defaultKind, done in zonkQuantifiedTyVar)
--- (b) There are no via-Indirect occurrences of the bound variables
--- in the types, because instantiation does not look through such things
--- (c) The call to tyVarsOfTypes is ok without looking through refs
tcExtendIdEnv ids thing_inside = tcExtendIdEnv2 [(idName id, id) | id <- ids] thing_inside
tcExtendIdEnv1 :: Name -> TcId -> TcM a -> TcM a
tcExtendIdEnv2 :: [(Name,TcId)] -> TcM a -> TcM a
-- Invariant: the TcIds are fully zonked (see tcExtendIdEnv above)
tcExtendIdEnv2 names_w_ids thing_inside
- = getLclEnv `thenM` \ env ->
- let
- extra_global_tyvars = tcTyVarsOfTypes [idType id | (_,id) <- names_w_ids]
- th_lvl = thLevel (tcl_th_ctxt env)
- extra_env = [ (name, ATcId { tct_id = id,
- tct_level = th_lvl,
- tct_type = id_ty,
- tct_co = if isRefineableTy id_ty
- then Just idHsWrapper
- else Nothing })
- | (name,id) <- names_w_ids, let id_ty = idType id]
- le' = extendNameEnvList (tcl_env env) extra_env
- rdr_env' = extendLocalRdrEnv (tcl_rdr env) [name | (name,_) <- names_w_ids]
- in
- traceTc (text "env2") `thenM_`
- traceTc (text "env3" <+> ppr extra_env) `thenM_`
- tc_extend_gtvs (tcl_tyvars env) extra_global_tyvars `thenM` \ gtvs' ->
- (traceTc (text "env4") `thenM_`
- setLclEnv (env {tcl_env = le', tcl_tyvars = gtvs', tcl_rdr = rdr_env'}) thing_inside)
+ = do { env <- getLclEnv
+ ; tc_extend_local_id_env env (thLevel (tcl_th_ctxt env)) names_w_ids thing_inside }
+
+tcExtendGhciEnv :: [TcId] -> TcM a -> TcM a
+-- Used to bind Ids for GHCi identifiers bound earlier in the user interaction
+-- Note especially that we bind them at TH level 'impLevel'. That's because it's
+-- OK to use a variable bound earlier in the interaction in a splice, becuase
+-- GHCi has already compiled it to bytecode
+tcExtendGhciEnv ids thing_inside
+ = do { env <- getLclEnv
+ ; tc_extend_local_id_env env impLevel [(idName id, id) | id <- ids] thing_inside }
+
+tc_extend_local_id_env -- This is the guy who does the work
+ :: TcLclEnv
+ -> ThLevel
+ -> [(Name,TcId)]
+ -> TcM a -> TcM a
+-- Invariant: the TcIds are fully zonked. Reasons:
+-- (a) The kinds of the forall'd type variables are defaulted
+-- (see Kind.defaultKind, done in zonkQuantifiedTyVar)
+-- (b) There are no via-Indirect occurrences of the bound variables
+-- in the types, because instantiation does not look through such things
+-- (c) The call to tyVarsOfTypes is ok without looking through refs
+
+tc_extend_local_id_env env th_lvl names_w_ids thing_inside
+ = do { traceTc (text "env2")
+ ; traceTc (text "env3" <+> ppr extra_env)
+ ; gtvs' <- tc_extend_gtvs (tcl_tyvars env) extra_global_tyvars
+ ; let env' = env {tcl_env = le', tcl_tyvars = gtvs', tcl_rdr = rdr_env'}
+ ; setLclEnv env' thing_inside }
+ where
+ extra_global_tyvars = tcTyVarsOfTypes [idType id | (_,id) <- names_w_ids]
+ extra_env = [ (name, ATcId { tct_id = id,
+ tct_level = th_lvl,
+ tct_type = id_ty,
+ tct_co = if isRefineableTy id_ty
+ then Just idHsWrapper
+ else Nothing })
+ | (name,id) <- names_w_ids, let id_ty = idType id]
+ le' = extendNameEnvList (tcl_env env) extra_env
+ rdr_env' = extendLocalRdrEnv (tcl_rdr env) [name | (name,_) <- names_w_ids]
\end{code}
-- I don't think I have to refine the set of global type variables in scope
-- Reason: the refinement never increases that set
refineEnvironment reft thing_inside
+ | isEmptyRefinement reft -- Common case
+ = thing_inside
+ | otherwise
= do { env <- getLclEnv
; let le' = mapNameEnv refine (tcl_env env)
; setLclEnv (env {tcl_env = le'}) thing_inside }
name, like otber top-level names, and hence must be made with newGlobalBinder.
\begin{code}
-newDFunName :: Class -> [Type] -> SrcLoc -> TcM Name
+newDFunName :: Class -> [Type] -> SrcSpan -> TcM Name
newDFunName clas (ty:_) loc
= do { index <- nextDFunIndex
; is_boot <- tcIsHsBoot
newDFunName clas [] loc = pprPanic "newDFunName" (ppr clas <+> ppr loc)
\end{code}
-Make a name for the representation tycon of a data/newtype instance. It's an
+Make a name for the representation tycon of a family instance. It's an
*external* name, like otber top-level names, and hence must be made with
newGlobalBinder.
\begin{code}
-newFamInstTyConName :: Name -> SrcLoc -> TcM Name
+newFamInstTyConName :: Name -> SrcSpan -> TcM Name
newFamInstTyConName tc_name loc
= do { index <- nextDFunIndex
; mod <- getModule
wrongThingErr expected thing name
= failWithTc (pprTcTyThingCategory thing <+> quotes (ppr name) <+>
ptext SLIT("used as a") <+> text expected)
+
+famInstNotFound tycon tys what
+ = failWithTc (msg <+> quotes (pprTypeApp tycon (ppr tycon) tys))
+ where
+ msg = ptext $ if length what > 1
+ then SLIT("More than one family instance for")
+ else SLIT("No family instance exactly matching")
\end{code}
projects / ghc-hetmet.git / blobdiff