-> [Id] -> [EquationInfo] -> Type
-> DsM CoreExpr
matchEquations ctxt vars eqns_info rhs_ty
- = do { dflags <- getDOptsDs
- ; locn <- getSrcSpanDs
- ; let ds_ctxt = DsMatchContext ctxt locn
+ = do { locn <- getSrcSpanDs
+ ; let ds_ctxt = DsMatchContext ctxt locn
error_doc = matchContextErrString ctxt
- ; match_result <- match_fun dflags ds_ctxt vars rhs_ty eqns_info
+ ; match_result <- matchCheck ds_ctxt vars rhs_ty eqns_info
; fail_expr <- mkErrorAppDs pAT_ERROR_ID rhs_ty error_doc
; extractMatchResult match_result fail_expr }
- where
- match_fun dflags ds_ctxt
- = case ctxt of
- LambdaExpr | dopt Opt_WarnSimplePatterns dflags -> matchCheck ds_ctxt
- | otherwise -> match
- _ -> matchCheck ds_ctxt
\end{code}
%************************************************************************
-> CoreExpr -- Return this if it matches
-> CoreExpr -- Return this if it doesn't
-> DsM CoreExpr
-
+-- Do not warn about incomplete patterns; see matchSinglePat comments
matchSimply scrut hs_ctx pat result_expr fail_expr = do
let
match_result = cantFailMatchResult result_expr
matchSinglePat :: CoreExpr -> HsMatchContext Name -> LPat Id
-> Type -> MatchResult -> DsM MatchResult
-matchSinglePat (Var var) hs_ctx (L _ pat) ty match_result = do
- dflags <- getDOptsDs
- locn <- getSrcSpanDs
- let
- match_fn dflags
- | dopt Opt_WarnSimplePatterns dflags = matchCheck ds_ctx
- | otherwise = match
- where
- ds_ctx = DsMatchContext hs_ctx locn
- match_fn dflags [var] ty [EqnInfo { eqn_pats = [pat], eqn_rhs = match_result }]
+-- 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