X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FhsSyn%2FHsPat.lhs;h=506537517d755ebf7c45d1999361bdee433da744;hp=6cad66c67e943cb649d98c9a07b8adfeabcc16e7;hb=6f8ff0bbad3b9fa389c960ad1b5a267a1ae502f1;hpb=dd99b6f8c61f393087d03cd697c06051a43ca4e9 diff --git a/compiler/hsSyn/HsPat.lhs b/compiler/hsSyn/HsPat.lhs index 6cad66c..5065375 100644 --- a/compiler/hsSyn/HsPat.lhs +++ b/compiler/hsSyn/HsPat.lhs @@ -19,16 +19,14 @@ module HsPat ( HsConPatDetails, hsConPatArgs, HsRecFields(..), HsRecField(..), hsRecFields, - HsQuasiQuote(..), - mkPrefixConPat, mkCharLitPat, mkNilPat, mkCoPat, mkCoPatCoI, - isBangHsBind, + isBangHsBind, hsPatNeedsParens, patsAreAllCons, isConPat, isSigPat, isWildPat, - patsAreAllLits, isLitPat, isIrrefutableHsPat - ) where + patsAreAllLits, isLitPat, isIrrefutableHsPat, -#include "HsVersions.h" + pprParendLPat + ) where import {-# SOURCE #-} HsExpr (SyntaxExpr, LHsExpr, pprLExpr) @@ -177,15 +175,23 @@ However HsRecFields is used only for patterns and expressions \begin{code} data HsRecFields id arg -- A bunch of record fields -- { x = 3, y = True } - -- Used for both expressiona and patterns + -- Used for both expressions and patterns = HsRecFields { rec_flds :: [HsRecField id arg], - rec_dotdot :: Maybe Int } - -- Nothing => the normal case - -- Just n => the group uses ".." notation, - -- and the first n elts of rec_flds - -- were the user-written ones - -- (In the latter case, the remaining elts of - -- rec_flds are the non-user-written ones) + rec_dotdot :: Maybe Int } -- Note [DotDot fields] + +-- Note [DotDot fields] +-- ~~~~~~~~~~~~~~~~~~~~ +-- The rec_dotdot field means this: +-- Nothing => the normal case +-- Just n => the group uses ".." notation, +-- +-- In the latter case: +-- +-- *before* renamer: rec_flds are exactly the n user-written fields +-- +-- *after* renamer: rec_flds includes *all* fields, with +-- the first 'n' being the user-written ones +-- and the remainder being 'filled in' implicitly data HsRecField id arg = HsRecField { hsRecFieldId :: Located id, @@ -198,23 +204,17 @@ data HsRecField id arg = HsRecField { -- If you write T { x, y = v+1 }, the HsRecFields will be -- HsRecField x x True ... -- HsRecField y (v+1) False ... --- That is, for "punned" field x is immediately expanded to x=x --- but with a punning flag so we can detect it later +-- That is, for "punned" field x is expanded (in the renamer) +-- to x=x; but with a punning flag so we can detect it later -- (e.g. when pretty printing) +-- +-- If the original field was qualified, we un-qualify it, thus +-- T { A.x } means T { A.x = x } hsRecFields :: HsRecFields id arg -> [id] hsRecFields rbinds = map (unLoc . hsRecFieldId) (rec_flds rbinds) \end{code} -\begin{code} -data HsQuasiQuote id = HsQuasiQuote - id - id - SrcSpan - FastString -\end{code} - - %************************************************************************ %* * %* Printing patterns @@ -234,15 +234,31 @@ pprPatBndr var -- Print with type info if -dppr-debug is on else ppr var +pprParendLPat :: (OutputableBndr name) => LPat name -> SDoc +pprParendLPat (L _ p) = pprParendPat p + +pprParendPat :: (OutputableBndr name) => Pat name -> SDoc +pprParendPat p | patNeedsParens p = parens (pprPat p) + | otherwise = pprPat p + +patNeedsParens :: Pat name -> Bool +patNeedsParens (ConPatIn _ d) = not (null (hsConPatArgs d)) +patNeedsParens (ConPatOut { pat_args = d }) = not (null (hsConPatArgs d)) +patNeedsParens (SigPatIn {}) = True +patNeedsParens (SigPatOut {}) = True +patNeedsParens (ViewPat {}) = True +patNeedsParens (CoPat {}) = True +patNeedsParens _ = False + pprPat :: (OutputableBndr name) => Pat name -> SDoc pprPat (VarPat var) = pprPatBndr var -pprPat (VarPatOut var bs) = parens (pprPatBndr var <+> braces (ppr bs)) +pprPat (VarPatOut var bs) = pprPatBndr var <+> braces (ppr bs) pprPat (WildPat _) = char '_' -pprPat (LazyPat pat) = char '~' <> ppr pat -pprPat (BangPat pat) = char '!' <> ppr pat -pprPat (AsPat name pat) = parens (hcat [ppr name, char '@', ppr pat]) -pprPat (ViewPat expr pat _) = parens (hcat [pprLExpr expr, text " -> ", ppr pat]) -pprPat (ParPat pat) = parens (ppr pat) +pprPat (LazyPat pat) = char '~' <> pprParendLPat pat +pprPat (BangPat pat) = char '!' <> pprParendLPat pat +pprPat (AsPat name pat) = hcat [ppr name, char '@', pprParendLPat pat] +pprPat (ViewPat expr pat _) = hcat [pprLExpr expr, text " -> ", ppr pat] +pprPat (ParPat pat) = parens (ppr pat) pprPat (ListPat pats _) = brackets (interpp'SP pats) pprPat (PArrPat pats _) = pabrackets (interpp'SP pats) pprPat (TuplePat pats bx _) = tupleParens bx (interpp'SP pats) @@ -257,26 +273,23 @@ pprPat (ConPatOut { pat_con = con, pat_tvs = tvs, pat_dicts = dicts, pprLHsBinds binds, pprConArgs details] else pprUserCon con details -pprPat (LitPat s) = ppr s +pprPat (LitPat s) = ppr s pprPat (NPat l Nothing _) = ppr l pprPat (NPat l (Just _) _) = char '-' <> ppr l -pprPat (NPlusKPat n k _ _) = hcat [ppr n, char '+', ppr k] -pprPat (QuasiQuotePat (HsQuasiQuote name quoter _ quote)) - = char '$' <> brackets (ppr name) <> - ptext SLIT("[:") <> ppr quoter <> ptext SLIT("|") <> - ppr quote <> ptext SLIT("|]") -pprPat (TypePat ty) = ptext SLIT("{|") <> ppr ty <> ptext SLIT("|}") -pprPat (CoPat co pat _) = parens (pprHsWrapper (ppr pat) co) -pprPat (SigPatIn pat ty) = ppr pat <+> dcolon <+> ppr ty -pprPat (SigPatOut pat ty) = ppr pat <+> dcolon <+> ppr ty +pprPat (NPlusKPat n k _ _) = hcat [ppr n, char '+', ppr k] +pprPat (QuasiQuotePat qq) = ppr qq +pprPat (TypePat ty) = ptext (sLit "{|") <> ppr ty <> ptext (sLit "|}") +pprPat (CoPat co pat _) = pprHsWrapper (ppr pat) co +pprPat (SigPatIn pat ty) = ppr pat <+> dcolon <+> ppr ty +pprPat (SigPatOut pat ty) = ppr pat <+> dcolon <+> ppr ty pprUserCon :: (Outputable con, OutputableBndr id) => con -> HsConPatDetails id -> SDoc pprUserCon c (InfixCon p1 p2) = ppr p1 <+> ppr c <+> ppr p2 pprUserCon c details = ppr c <+> pprConArgs details pprConArgs :: OutputableBndr id => HsConPatDetails id -> SDoc -pprConArgs (PrefixCon pats) = interppSP pats -pprConArgs (InfixCon p1 p2) = interppSP [p1,p2] +pprConArgs (PrefixCon pats) = sep (map pprParendLPat pats) +pprConArgs (InfixCon p1 p2) = sep [pprParendLPat p1, pprParendLPat p2] pprConArgs (RecCon rpats) = ppr rpats instance (OutputableBndr id, Outputable arg) @@ -286,18 +299,18 @@ instance (OutputableBndr id, Outputable arg) ppr (HsRecFields { rec_flds = flds, rec_dotdot = Just n }) = braces (fsep (punctuate comma (map ppr (take n flds) ++ [dotdot]))) where - dotdot = ptext SLIT("..") <+> ifPprDebug (ppr (drop n flds)) + dotdot = ptext (sLit "..") <+> ifPprDebug (ppr (drop n flds)) instance (OutputableBndr id, Outputable arg) => Outputable (HsRecField id arg) where ppr (HsRecField { hsRecFieldId = f, hsRecFieldArg = arg, hsRecPun = pun }) - = ppr f <+> (if pun then empty else equals <+> ppr arg) + = ppr f <+> (ppUnless pun $ equals <+> ppr arg) -- add parallel array brackets around a document -- pabrackets :: SDoc -> SDoc -pabrackets p = ptext SLIT("[:") <> p <> ptext SLIT(":]") +pabrackets p = ptext (sLit "[:") <> p <> ptext (sLit ":]") \end{code} @@ -410,12 +423,12 @@ isIrrefutableHsPat :: OutputableBndr id => LPat id -> Bool isIrrefutableHsPat pat = go pat where - go (L _ pat) = go1 pat + go (L _ pat) = go1 pat - go1 (WildPat _) = True - go1 (VarPat _) = True - go1 (VarPatOut _ _) = True - go1 (LazyPat _) = True + go1 (WildPat {}) = True + go1 (VarPat {}) = True + go1 (VarPatOut {}) = True + go1 (LazyPat {}) = True go1 (BangPat pat) = go pat go1 (CoPat _ pat _) = go1 pat go1 (ParPat pat) = go pat @@ -424,22 +437,50 @@ isIrrefutableHsPat pat go1 (SigPatIn pat _) = go pat go1 (SigPatOut pat _) = go pat go1 (TuplePat pats _ _) = all go pats - go1 (ListPat _ _) = False - go1 (PArrPat _ _) = False -- ? + go1 (ListPat {}) = False + go1 (PArrPat {}) = False -- ? - go1 (ConPatIn _ _) = False -- Conservative + go1 (ConPatIn {}) = False -- Conservative go1 (ConPatOut{ pat_con = L _ con, pat_args = details }) = isProductTyCon (dataConTyCon con) && all go (hsConPatArgs details) - go1 (LitPat _) = False - go1 (NPat _ _ _) = False - go1 (NPlusKPat _ _ _ _) = False + go1 (LitPat {}) = False + go1 (NPat {}) = False + go1 (NPlusKPat {}) = False go1 (QuasiQuotePat {}) = urk pat -- Gotten rid of by renamer, before -- isIrrefutablePat is called go1 (TypePat {}) = urk pat urk pat = pprPanic "isIrrefutableHsPat:" (ppr pat) + +hsPatNeedsParens :: Pat a -> Bool +hsPatNeedsParens (WildPat {}) = False +hsPatNeedsParens (VarPat {}) = False +hsPatNeedsParens (VarPatOut {}) = True +hsPatNeedsParens (LazyPat {}) = False +hsPatNeedsParens (BangPat {}) = False +hsPatNeedsParens (CoPat {}) = True +hsPatNeedsParens (ParPat {}) = False +hsPatNeedsParens (AsPat {}) = False +hsPatNeedsParens (ViewPat {}) = True +hsPatNeedsParens (SigPatIn {}) = True +hsPatNeedsParens (SigPatOut {}) = True +hsPatNeedsParens (TuplePat {}) = False +hsPatNeedsParens (ListPat {}) = False +hsPatNeedsParens (PArrPat {}) = False +hsPatNeedsParens (ConPatIn _ ds) = conPatNeedsParens ds +hsPatNeedsParens (ConPatOut {}) = True +hsPatNeedsParens (LitPat {}) = False +hsPatNeedsParens (NPat {}) = False +hsPatNeedsParens (NPlusKPat {}) = True +hsPatNeedsParens (QuasiQuotePat {}) = True +hsPatNeedsParens (TypePat {}) = False + +conPatNeedsParens :: HsConDetails a b -> Bool +conPatNeedsParens (PrefixCon args) = not (null args) +conPatNeedsParens (InfixCon {}) = False +conPatNeedsParens (RecCon {}) = False \end{code}