Matching guarded right-hand-sides (GRHSs)
\begin{code}
-{-# OPTIONS -w #-}
+{-# OPTIONS -fno-warn-incomplete-patterns #-}
-- 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
import {-# SOURCE #-} Match ( matchSinglePat )
import HsSyn
+import MkCore
import CoreSyn
import Var
import Type
import DsMonad
import DsUtils
-import PrelInfo
import TysWiredIn
import PrelNames
import Name
import SrcLoc
-
-import Control.Monad ((>=>))
-
+import Outputable
\end{code}
@dsGuarded@ is used for both @case@ expressions and pattern bindings.
dsGuarded grhss rhs_ty = do
match_result <- dsGRHSs PatBindRhs [] grhss rhs_ty
- error_expr <- mkErrorAppDs nON_EXHAUSTIVE_GUARDS_ERROR_ID rhs_ty ""
+ error_expr <- mkErrorAppDs nON_EXHAUSTIVE_GUARDS_ERROR_ID rhs_ty empty
extractMatchResult match_result error_expr
\end{code}
-> GRHSs Id -- Guarded RHSs
-> Type -- Type of RHS
-> DsM MatchResult
-dsGRHSs hs_ctx pats grhssa@(GRHSs grhss binds) rhs_ty = do
+dsGRHSs hs_ctx pats (GRHSs grhss binds) rhs_ty = do
match_results <- mapM (dsGRHS hs_ctx pats rhs_ty) grhss
let
match_result1 = foldr1 combineMatchResults match_results
--
return match_result2
-dsGRHS hs_ctx pats rhs_ty (L loc (GRHS guards rhs))
- = matchGuards (map unLoc guards) hs_ctx rhs rhs_ty
+dsGRHS :: HsMatchContext Name -> [Pat Id] -> Type -> LGRHS Id -> DsM MatchResult
+dsGRHS hs_ctx _ rhs_ty (L _ (GRHS guards rhs))
+ = matchGuards (map unLoc guards) (PatGuard hs_ctx) rhs rhs_ty
\end{code}
\begin{code}
matchGuards :: [Stmt Id] -- Guard
- -> HsMatchContext Name -- Context
+ -> HsStmtContext Name -- Context
-> LHsExpr Id -- RHS
-> Type -- Type of RHS of guard
-> DsM MatchResult
-- See comments with HsExpr.Stmt re what an ExprStmt means
-- Here we must be in a guard context (not do-expression, nor list-comp)
-matchGuards [] ctx rhs rhs_ty
+matchGuards [] _ rhs _
= do { core_rhs <- dsLExpr rhs
; return (cantFailMatchResult core_rhs) }
matchGuards (BindStmt pat bind_rhs _ _ : stmts) ctx rhs rhs_ty = do
match_result <- matchGuards stmts ctx rhs rhs_ty
core_rhs <- dsLExpr bind_rhs
- matchSinglePat core_rhs ctx pat rhs_ty match_result
+ matchSinglePat core_rhs (StmtCtxt ctx) pat rhs_ty match_result
isTrueLHsExpr :: LHsExpr Id -> Maybe (CoreExpr -> DsM CoreExpr)
|| v `hasKey` getUnique trueDataConId
= Just return
-- trueDataConId doesn't have the same unique as trueDataCon
-isTrueLHsExpr (L loc (HsTick ix frees e))
- | Just ticks <- isTrueLHsExpr e = Just (ticks >=> mkTickBox ix frees)
+isTrueLHsExpr (L _ (HsTick ix frees e))
+ | Just ticks <- isTrueLHsExpr e = Just (\x -> ticks x >>= mkTickBox ix frees)
-- This encodes that the result is constant True for Hpc tick purposes;
-- which is specifically what isTrueLHsExpr is trying to find out.
-isTrueLHsExpr (L loc (HsBinTick ixT _ e))
- | Just ticks <- isTrueLHsExpr e = Just (ticks >=> mkTickBox ixT [])
+isTrueLHsExpr (L _ (HsBinTick ixT _ e))
+ | Just ticks <- isTrueLHsExpr e = Just (\x -> ticks x >>= mkTickBox ixT [])
isTrueLHsExpr (L _ (HsPar e)) = isTrueLHsExpr e
-isTrueLHsExpr other = Nothing
+isTrueLHsExpr _ = Nothing
\end{code}
Should {\em fail} if @e@ returns @D@