2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section{@VarEnvs@: Variable environments}
8 VarEnv, IdEnv, TyVarEnv,
9 emptyVarEnv, unitVarEnv, mkVarEnv,
10 elemVarEnv, rngVarEnv,
11 extendVarEnv, extendVarEnvList,
12 plusVarEnv, plusVarEnv_C,
13 delVarEnvList, delVarEnv,
14 lookupVarEnv, lookupVarEnv_NF, lookupWithDefaultVarEnv,
16 modifyVarEnv, modifyVarEnv_Directly,
17 isEmptyVarEnv, foldVarEnv,
20 TidyEnv, emptyTidyEnv,
23 SubstEnv, TyVarSubstEnv, SubstResult(..),
25 mkSubstEnv, lookupSubstEnv, extendSubstEnv, extendSubstEnvList,
26 delSubstEnv, noTypeSubst, isEmptySubstEnv
29 #include "HsVersions.h"
31 import {-# SOURCE #-} CoreSyn( CoreExpr )
32 import {-# SOURCE #-} TypeRep( Type )
34 import BasicTypes ( OccInfo )
35 import OccName ( TidyOccEnv, emptyTidyOccEnv )
36 import Var ( Var, Id )
38 import Util ( zipEqual )
42 %************************************************************************
46 %************************************************************************
48 When tidying up print names, we keep a mapping of in-scope occ-names
49 (the TidyOccEnv) and a Var-to-Var of the current renamings.
52 type TidyEnv = (TidyOccEnv, VarEnv Var)
53 emptyTidyEnv = (emptyTidyOccEnv, emptyVarEnv)
57 %************************************************************************
59 \subsection{Substitution environments}
61 %************************************************************************
65 noTys :: SubstResult -> Bool -> Bool
66 noTys (DoneTy ty) no_tys = False
67 noTys other no_tys = no_tys
69 data SubstEnv = SE (VarEnv SubstResult)
70 Bool -- True => definitely no type substitutions in the env
72 noTypeSubst :: SubstEnv -> Bool
73 noTypeSubst (SE _ nt) = nt
75 type TyVarSubstEnv = SubstEnv -- of the form (DoneTy ty) *only*
78 = DoneEx CoreExpr -- Completed term
79 | DoneId Id OccInfo -- Completed term variable, with occurrence info; only
80 -- used by the simplifier
81 | DoneTy Type -- Completed type
82 | ContEx SubstEnv CoreExpr -- A suspended substitution
84 emptySubstEnv :: SubstEnv
85 emptySubstEnv = SE emptyVarEnv True
87 isEmptySubstEnv :: SubstEnv -> Bool
88 isEmptySubstEnv (SE s _) = isEmptyVarEnv s
90 lookupSubstEnv :: SubstEnv -> Var -> Maybe SubstResult
91 lookupSubstEnv (SE s _) v = lookupVarEnv s v
93 extendSubstEnv :: SubstEnv -> Var -> SubstResult -> SubstEnv
94 extendSubstEnv (SE s nt) v r = SE (extendVarEnv s v r) (noTys r nt)
96 mkSubstEnv :: [Var] -> [SubstResult] -> SubstEnv
97 mkSubstEnv bs vs = extendSubstEnvList emptySubstEnv bs vs
99 extendSubstEnvList :: SubstEnv -> [Var] -> [SubstResult] -> SubstEnv
100 extendSubstEnvList env [] [] = env
101 extendSubstEnvList (SE env nt) (b:bs) (r:rs) = extendSubstEnvList (SE (extendVarEnv env b r) (noTys r nt)) bs rs
103 delSubstEnv :: SubstEnv -> Var -> SubstEnv
104 delSubstEnv (SE s nt) v = SE (delVarEnv s v) nt
108 %************************************************************************
110 \subsection{@VarEnv@s}
112 %************************************************************************
115 type VarEnv elt = UniqFM elt
116 type IdEnv elt = VarEnv elt
117 type TyVarEnv elt = VarEnv elt
119 emptyVarEnv :: VarEnv a
120 mkVarEnv :: [(Var, a)] -> VarEnv a
121 zipVarEnv :: [Var] -> [a] -> VarEnv a
122 unitVarEnv :: Var -> a -> VarEnv a
123 extendVarEnv :: VarEnv a -> Var -> a -> VarEnv a
124 plusVarEnv :: VarEnv a -> VarEnv a -> VarEnv a
125 extendVarEnvList :: VarEnv a -> [(Var, a)] -> VarEnv a
127 delVarEnvList :: VarEnv a -> [Var] -> VarEnv a
128 delVarEnv :: VarEnv a -> Var -> VarEnv a
129 plusVarEnv_C :: (a -> a -> a) -> VarEnv a -> VarEnv a -> VarEnv a
130 mapVarEnv :: (a -> b) -> VarEnv a -> VarEnv b
131 modifyVarEnv :: (a -> a) -> VarEnv a -> Var -> VarEnv a
132 rngVarEnv :: VarEnv a -> [a]
134 isEmptyVarEnv :: VarEnv a -> Bool
135 lookupVarEnv :: VarEnv a -> Var -> Maybe a
136 lookupVarEnv_NF :: VarEnv a -> Var -> a
137 lookupWithDefaultVarEnv :: VarEnv a -> a -> Var -> a
138 elemVarEnv :: Var -> VarEnv a -> Bool
139 foldVarEnv :: (a -> b -> b) -> b -> VarEnv a -> b
144 extendVarEnv = addToUFM
145 plusVarEnv_C = plusUFM_C
146 delVarEnvList = delListFromUFM
147 delVarEnv = delFromUFM
149 lookupVarEnv = lookupUFM
150 lookupWithDefaultVarEnv = lookupWithDefaultUFM
153 emptyVarEnv = emptyUFM
156 isEmptyVarEnv = isNullUFM
159 zipVarEnv tyvars tys = listToUFM (zipEqual "zipVarEnv" tyvars tys)
160 extendVarEnvList env pairs = plusUFM env (listToUFM pairs)
161 lookupVarEnv_NF env id = case (lookupVarEnv env id) of { Just xx -> xx }
164 @modifyVarEnv@: Look up a thing in the VarEnv,
165 then mash it with the modify function, and put it back.
168 modifyVarEnv mangle_fn env key
169 = case (lookupVarEnv env key) of
171 Just xx -> extendVarEnv env key (mangle_fn xx)
173 modifyVarEnv_Directly mangle_fn env key
174 = case (lookupUFM_Directly env key) of
176 Just xx -> addToUFM_Directly env key (mangle_fn xx)