import MatchCon
import MatchLit
import Type
+import Coercion
import TysWiredIn
import ListSetOps
import SrcLoc
import Outputable
import FastString
+import Control.Monad( when )
import qualified Data.Map as Map
\end{code}
-> [EquationInfo] -- Info about patterns, etc. (type synonym below)
-> DsM MatchResult -- Desugared result!
-matchCheck ctx vars ty qs = do
- dflags <- getDOptsDs
- matchCheck_really dflags ctx vars ty qs
+matchCheck ctx vars ty qs
+ = do { dflags <- getDOptsDs
+ ; matchCheck_really dflags ctx vars ty qs }
matchCheck_really :: DynFlags
-> DsMatchContext
-> Type
-> [EquationInfo]
-> DsM MatchResult
-matchCheck_really dflags ctx vars ty qs
- | incomplete && shadow = do
- dsShadowWarn ctx eqns_shadow
- dsIncompleteWarn ctx pats
- match vars ty qs
- | incomplete = do
- dsIncompleteWarn ctx pats
- match vars ty qs
- | shadow = do
- dsShadowWarn ctx eqns_shadow
- match vars ty qs
- | otherwise =
- match vars ty qs
- where (pats, eqns_shadow) = check qs
- incomplete = want_incomplete && (notNull pats)
- want_incomplete = case ctx of
- DsMatchContext RecUpd _ ->
- dopt Opt_WarnIncompletePatternsRecUpd dflags
- _ ->
- dopt Opt_WarnIncompletePatterns dflags
- shadow = dopt Opt_WarnOverlappingPatterns dflags
- && not (null eqns_shadow)
+matchCheck_really dflags ctx@(DsMatchContext hs_ctx _) vars ty qs
+ = do { when shadow (dsShadowWarn ctx eqns_shadow)
+ ; when incomplete (dsIncompleteWarn ctx pats)
+ ; match vars ty qs }
+ where
+ (pats, eqns_shadow) = check qs
+ incomplete = incomplete_flag hs_ctx && (notNull pats)
+ shadow = dopt Opt_WarnOverlappingPatterns dflags
+ && notNull eqns_shadow
+
+ incomplete_flag :: HsMatchContext id -> Bool
+ incomplete_flag (FunRhs {}) = dopt Opt_WarnIncompletePatterns dflags
+ incomplete_flag CaseAlt = dopt Opt_WarnIncompletePatterns dflags
+
+ incomplete_flag LambdaExpr = dopt Opt_WarnIncompleteUniPatterns dflags
+ incomplete_flag PatBindRhs = dopt Opt_WarnIncompleteUniPatterns dflags
+ incomplete_flag ProcExpr = dopt Opt_WarnIncompleteUniPatterns dflags
+
+ incomplete_flag RecUpd = dopt Opt_WarnIncompletePatternsRecUpd dflags
+
+ incomplete_flag ThPatQuote = False
+ incomplete_flag (StmtCtxt {}) = False -- Don't warn about incomplete patterns
+ -- in list comprehensions, pattern guards
+ -- etc. They are often *supposed* to be
+ -- incomplete
\end{code}
This variable shows the maximum number of lines of output generated for warnings.
tidy1 v (VarPat var)
= return (wrapBind var v, WildPat (idType var))
-tidy1 v (VarPatOut var binds)
- = do { ds_ev_binds <- dsTcEvBinds binds
- ; return (wrapBind var v . wrapDsEvBinds ds_ev_binds,
- WildPat (idType var)) }
-
-- case v of { x@p -> mr[] }
-- = case v of { p -> let x=v in mr[] }
tidy1 v (AsPat (L _ var) pat)
-- NPats: we *might* be able to replace these w/ a simpler form
tidy1 _ (NPat lit mb_neg eq)
- = return (idDsWrapper, tidyNPat lit mb_neg eq)
+ = return (idDsWrapper, tidyNPat tidyLitPat lit mb_neg eq)
-- BangPatterns: Pattern matching is already strict in constructors,
-- tuples etc, so the last case strips off the bang for thoses patterns.
tidy1 v (BangPat (L _ (LazyPat p))) = tidy1 v (BangPat p)
tidy1 v (BangPat (L _ (ParPat p))) = tidy1 v (BangPat p)
tidy1 _ p@(BangPat (L _(VarPat _))) = return (idDsWrapper, p)
-tidy1 _ p@(BangPat (L _(VarPatOut _ _))) = return (idDsWrapper, p)
tidy1 _ p@(BangPat (L _ (WildPat _))) = return (idDsWrapper, p)
tidy1 _ p@(BangPat (L _ (CoPat _ _ _))) = return (idDsWrapper, p)
tidy1 _ p@(BangPat (L _ (SigPatIn _ _))) = return (idDsWrapper, p)
match_result' <- matchSinglePat scrut hs_ctx pat rhs_ty match_result
extractMatchResult match_result' fail_expr
-
matchSinglePat :: CoreExpr -> HsMatchContext Name -> LPat Id
-> Type -> MatchResult -> DsM MatchResult
-- Do not warn about incomplete patterns
-- Used for things like [ e | pat <- stuff ], where
-- incomplete patterns are just fine
-matchSinglePat (Var var) _ (L _ pat) ty match_result
- = match [var] ty [EqnInfo { eqn_pats = [pat], eqn_rhs = match_result }]
-
-matchSinglePat scrut hs_ctx pat ty match_result = do
- var <- selectSimpleMatchVarL pat
- match_result' <- matchSinglePat (Var var) hs_ctx pat ty match_result
- return (adjustMatchResult (bindNonRec var scrut) match_result')
+matchSinglePat (Var var) ctx (L _ pat) ty match_result
+ = do { locn <- getSrcSpanDs
+ ; matchCheck (DsMatchContext ctx locn)
+ [var] ty
+ [EqnInfo { eqn_pats = [pat], eqn_rhs = match_result }] }
+
+matchSinglePat scrut hs_ctx pat ty match_result
+ = do { var <- selectSimpleMatchVarL pat
+ ; match_result' <- matchSinglePat (Var var) hs_ctx pat ty match_result
+ ; return (adjustMatchResult (bindNonRec var scrut) match_result') }
\end{code}
sameGroup (PgLit _) (PgLit _) = True -- One case expression
sameGroup (PgN l1) (PgN l2) = l1==l2 -- Order is significant
sameGroup (PgNpK l1) (PgNpK l2) = l1==l2 -- See Note [Grouping overloaded literal patterns]
-sameGroup (PgCo t1) (PgCo t2) = t1 `coreEqType` t2
+sameGroup (PgCo t1) (PgCo t2) = t1 `eqType` t2
-- CoPats are in the same goup only if the type of the
-- enclosed pattern is the same. The patterns outside the CoPat
-- always have the same type, so this boils down to saying that
-- which resolve the overloading (e.g., fromInteger 1),
-- because these expressions get written as a bunch of different variables
-- (presumably to improve sharing)
- tcEqType (overLitType l) (overLitType l') && l == l'
+ eqType (overLitType l) (overLitType l') && l == l'
exp (HsApp e1 e2) (HsApp e1' e2') = lexp e1 e1' && lexp e2 e2'
-- the fixities have been straightened out by now, so it's safe
-- to ignore them?
---------
tup_arg (Present e1) (Present e2) = lexp e1 e2
- tup_arg (Missing t1) (Missing t2) = tcEqType t1 t2
+ tup_arg (Missing t1) (Missing t2) = eqType t1 t2
tup_arg _ _ = False
---------
-- equating different ways of writing a coercion)
wrap WpHole WpHole = True
wrap (WpCompose w1 w2) (WpCompose w1' w2') = wrap w1 w1' && wrap w2 w2'
- wrap (WpCast c) (WpCast c') = tcEqType c c'
+ wrap (WpCast c) (WpCast c') = coreEqCoercion c c'
wrap (WpEvApp et1) (WpEvApp et2) = ev_term et1 et2
- wrap (WpTyApp t) (WpTyApp t') = tcEqType t t'
+ wrap (WpTyApp t) (WpTyApp t') = eqType t t'
-- Enhancement: could implement equality for more wrappers
-- if it seems useful (lams and lets)
wrap _ _ = False
---------
ev_term :: EvTerm -> EvTerm -> Bool
ev_term (EvId a) (EvId b) = a==b
- ev_term (EvCoercion a) (EvCoercion b) = tcEqType a b
+ ev_term (EvCoercion a) (EvCoercion b) = coreEqCoercion a b
ev_term _ _ = False
---------
cannot jump to the third equation! Because the same argument might
match '2'!
Hence we don't regard 1 and 2, or (n+1) and (n+2), as part of the same group.
+