diff options
Diffstat (limited to 'compiler/hsSyn/Convert.lhs')
| -rw-r--r-- | compiler/hsSyn/Convert.lhs | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/compiler/hsSyn/Convert.lhs b/compiler/hsSyn/Convert.lhs index c9cbfeffb5..5933e9d5fa 100644 --- a/compiler/hsSyn/Convert.lhs +++ b/compiler/hsSyn/Convert.lhs @@ -522,12 +522,15 @@ cvtHsDo do_or_lc stmts | null stmts = failWith (ptext (sLit "Empty stmt list in do-block")) | otherwise = do { stmts' <- cvtStmts stmts - ; body <- case last stmts' of - L _ (ExprStmt body _ _ _) -> return body - stmt' -> failWith (bad_last stmt') - ; return $ HsDo do_or_lc (init stmts') body noSyntaxExpr void } + ; let Just (stmts'', last') = snocView stmts' + + ; last'' <- case last' of + L loc (ExprStmt body _ _ _) -> return (L loc (mkLastStmt body)) + _ -> failWith (bad_last last') + + ; return $ HsDo do_or_lc (stmts'' ++ [last'']) void } where - bad_last stmt = vcat [ ptext (sLit "Illegal last statement of") <+> pprStmtContext do_or_lc <> colon + bad_last stmt = vcat [ ptext (sLit "Illegal last statement of") <+> pprAStmtContext do_or_lc <> colon , nest 2 $ Outputable.ppr stmt , ptext (sLit "(It should be an expression.)") ] |