X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FhsSyn%2FHsExpr.lhs;h=c3f38cac4bfaf9910887fd49a4df1ab0423841f7;hp=0800175f35b2d7887f2f079ba60a7eac56c83df1;hb=f04dead93a15af1cb818172f207b8a81d2c81298;hpb=ad2c24f54a992e7dc4c203b5504bec175c4acc98 diff --git a/compiler/hsSyn/HsExpr.lhs b/compiler/hsSyn/HsExpr.lhs index 0800175..c3f38ca 100644 --- a/compiler/hsSyn/HsExpr.lhs +++ b/compiler/hsSyn/HsExpr.lhs @@ -469,21 +469,24 @@ ppr_expr (HsProc pat (L _ (HsCmdTop cmd _ _ _))) = hsep [ptext (sLit "proc"), ppr pat, ptext (sLit "->"), ppr cmd] ppr_expr (HsTick tickId vars exp) - = hcat [ptext (sLit "tick<"), - ppr tickId, - ptext (sLit ">("), - hsep (map pprHsVar vars), - ppr exp, - ptext (sLit ")")] + = pprTicks (ppr exp) $ + hcat [ptext (sLit "tick<"), + ppr tickId, + ptext (sLit ">("), + hsep (map pprHsVar vars), + ppr exp, + ptext (sLit ")")] ppr_expr (HsBinTick tickIdTrue tickIdFalse exp) - = hcat [ptext (sLit "bintick<"), + = pprTicks (ppr exp) $ + hcat [ptext (sLit "bintick<"), ppr tickIdTrue, ptext (sLit ","), ppr tickIdFalse, ptext (sLit ">("), ppr exp,ptext (sLit ")")] ppr_expr (HsTickPragma externalSrcLoc exp) - = hcat [ptext (sLit "tickpragma<"), + = pprTicks (ppr exp) $ + hcat [ptext (sLit "tickpragma<"), ppr externalSrcLoc, ptext (sLit ">("), ppr exp, @@ -844,26 +847,41 @@ data StmtLR idL idR -- the names which they group over in statements -- Recursive statement (see Note [RecStmt] below) - | RecStmt [LStmtLR idL idR] - --- The next two fields are only valid after renaming - [idR] -- The ids are a subset of the variables bound by the - -- stmts that are used in stmts that follow the RecStmt - - [idR] -- Ditto, but these variables are the "recursive" ones, - -- that are used before they are bound in the stmts of - -- the RecStmt. From a type-checking point of view, - -- these ones have to be monomorphic - - --- These fields are only valid after typechecking - [PostTcExpr] -- These expressions correspond 1-to-1 with - -- the "recursive" [id], and are the - -- expressions that should be returned by - -- the recursion. - -- They may not quite be the Ids themselves, - -- because the Id may be *polymorphic*, but - -- the returned thing has to be *monomorphic*. - (DictBinds idR) -- Method bindings of Ids bound by the - -- RecStmt, and used afterwards + | RecStmt + { recS_stmts :: [LStmtLR idL idR] + + -- The next two fields are only valid after renaming + , recS_later_ids :: [idR] -- The ids are a subset of the variables bound by the + -- stmts that are used in stmts that follow the RecStmt + + , recS_rec_ids :: [idR] -- Ditto, but these variables are the "recursive" ones, + -- that are used before they are bound in the stmts of + -- the RecStmt. + + -- An Id can be in both groups + -- Both sets of Ids are (now) treated monomorphically + -- The only reason they are separate is becuase the DsArrows + -- code uses them separately, and I don't understand it well + -- enough to change it + + -- Rebindable syntax + , recS_bind_fn :: SyntaxExpr idR -- The bind function + , recS_ret_fn :: SyntaxExpr idR -- The return function + , recS_mfix_fn :: SyntaxExpr idR -- The mfix function + + -- These fields are only valid after typechecking + , recS_rec_rets :: [PostTcExpr] -- These expressions correspond 1-to-1 with + -- recS_rec_ids, and are the + -- expressions that should be returned by + -- the recursion. + -- They may not quite be the Ids themselves, + -- because the Id may be *polymorphic*, but + -- the returned thing has to be *monomorphic*, + -- so they may be type applications + + , recS_dicts :: DictBinds idR -- Method bindings of Ids bound by the + -- RecStmt, and used afterwards + } \end{code} ExprStmts are a bit tricky, because what they mean @@ -891,8 +909,8 @@ depends on the context. Consider the following contexts: Array comprehensions are handled like list comprehensions -=chak -Note [RecStmt] -~~~~~~~~~~~~~~ +Note [How RecStmt works] +~~~~~~~~~~~~~~~~~~~~~~~~ Example: HsDo [ BindStmt x ex @@ -914,6 +932,17 @@ Here, the RecStmt binds a,b,c; but Nota Bene: the two a's have different types, even though they have the same Name. +Note [Typing a RecStmt] +~~~~~~~~~~~~~~~~~~~~~~~ +A (RecStmt stmts) types as if you had written + + (v1,..,vn, _, ..., _) <- mfix (\~(_, ..., _, r1, ..., rm) -> + do { stmts + ; return (v1,..vn, r1, ..., rm) }) + +where v1..vn are the later_ids + r1..rm are the rec_ids + \begin{code} instance (OutputableBndr idL, OutputableBndr idR) => Outputable (StmtLR idL idR) where @@ -931,7 +960,11 @@ pprStmt (TransformStmt (stmts, _) usingExpr maybeByExpr) byExprDoc = maybe empty (\byExpr -> hsep [ptext (sLit "by"), ppr byExpr]) maybeByExpr pprStmt (GroupStmt (stmts, _) groupByClause) = (hsep [stmtsDoc, ptext (sLit "then group"), pprGroupByClause groupByClause]) where stmtsDoc = interpp'SP stmts -pprStmt (RecStmt segment _ _ _ _) = ptext (sLit "rec") <+> braces (vcat (map ppr segment)) +pprStmt (RecStmt { recS_stmts = segment, recS_rec_ids = rec_ids, recS_later_ids = later_ids }) + = ptext (sLit "rec") <+> + vcat [ braces (vcat (map ppr segment)) + , ifPprDebug (vcat [ ptext (sLit "rec_ids=") <> ppr rec_ids + , ptext (sLit "later_ids=") <> ppr later_ids])] pprGroupByClause :: (OutputableBndr id) => GroupByClause id -> SDoc pprGroupByClause (GroupByNothing usingExpr) = hsep [ptext (sLit "using"), ppr usingExpr] @@ -939,12 +972,19 @@ pprGroupByClause (GroupBySomething eitherUsingExpr byExpr) = hsep [ptext (sLit " where usingExprDoc = either (\usingExpr -> hsep [ptext (sLit "using"), ppr usingExpr]) (const empty) eitherUsingExpr pprDo :: OutputableBndr id => HsStmtContext any -> [LStmt id] -> LHsExpr id -> SDoc -pprDo DoExpr stmts body = ptext (sLit "do") <+> pprDeeperList vcat (map ppr stmts ++ [ppr body]) -pprDo (MDoExpr _) stmts body = ptext (sLit "mdo") <+> pprDeeperList vcat (map ppr stmts ++ [ppr body]) +pprDo DoExpr stmts body = ptext (sLit "do") <+> ppr_do_stmts stmts body +pprDo (MDoExpr _) stmts body = ptext (sLit "mdo") <+> ppr_do_stmts stmts body pprDo ListComp stmts body = pprComp brackets stmts body pprDo PArrComp stmts body = pprComp pa_brackets stmts body pprDo _ _ _ = panic "pprDo" -- PatGuard, ParStmtCxt +ppr_do_stmts :: OutputableBndr id => [LStmt id] -> LHsExpr id -> SDoc +-- Print a bunch of do stmts, with explicit braces and semicolons, +-- so that we are not vulnerable to layout bugs +ppr_do_stmts stmts body + = lbrace <+> pprDeeperList vcat ([ ppr s <> semi | s <- stmts] ++ [ppr body]) + <+> rbrace + pprComp :: OutputableBndr id => (SDoc -> SDoc) -> [LStmt id] -> LHsExpr id -> SDoc pprComp brack quals body = brack $