X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FhsSyn%2FHsPat.lhs;h=af921de689221cfa825a35f55b3946a744ca204f;hb=fb6d198f498d4e325a540f28aaa6e1d1530839c3;hp=6b294c1c42237e6c31bbf764e126b2b44ecb1105;hpb=83e979b3db9acba32973ce065fce6248ee0f59a6;p=ghc-hetmet.git diff --git a/compiler/hsSyn/HsPat.lhs b/compiler/hsSyn/HsPat.lhs index 6b294c1..af921de 100644 --- a/compiler/hsSyn/HsPat.lhs +++ b/compiler/hsSyn/HsPat.lhs @@ -23,13 +23,11 @@ module HsPat ( mkPrefixConPat, mkCharLitPat, mkNilPat, mkCoPat, mkCoPatCoI, - isBangHsBind, + isBangHsBind, hsPatNeedsParens, patsAreAllCons, isConPat, isSigPat, isWildPat, patsAreAllLits, isLitPat, isIrrefutableHsPat ) where -#include "HsVersions.h" - import {-# SOURCE #-} HsExpr (SyntaxExpr, LHsExpr, pprLExpr) -- friends: @@ -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, @@ -198,9 +204,12 @@ 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) @@ -212,6 +221,15 @@ data HsQuasiQuote id = HsQuasiQuote id SrcSpan FastString + +instance OutputableBndr id => Outputable (HsQuasiQuote id) where + ppr = ppr_qq + +ppr_qq :: OutputableBndr id => HsQuasiQuote id -> SDoc +ppr_qq (HsQuasiQuote name quoter _ quote) = + char '$' <> brackets (ppr name) <> + ptext (sLit "[:") <> ppr quoter <> ptext (sLit "|") <> + ppr quote <> ptext (sLit "|]") \end{code} @@ -241,8 +259,8 @@ pprPat (WildPat _) = char '_' pprPat (LazyPat pat) = char '~' <> ppr pat pprPat (BangPat pat) = char '!' <> ppr pat pprPat (AsPat name pat) = parens (hcat [ppr name, char '@', ppr pat]) -pprPat (ViewPat expr pat _) = parens (hcat [pprLExpr expr, text " -> ", ppr pat]) -pprPat (ParPat pat) = parens (ppr pat) +pprPat (ViewPat expr pat _) = parens (hcat [pprLExpr expr, text " -> ", ppr pat]) +pprPat (ParPat pat) = parens (ppr pat) pprPat (ListPat pats _) = brackets (interpp'SP pats) pprPat (PArrPat pats _) = pabrackets (interpp'SP pats) pprPat (TuplePat pats bx _) = tupleParens bx (interpp'SP pats) @@ -263,9 +281,9 @@ pprPat (NPat l (Just _) _) = char '-' <> ppr l pprPat (NPlusKPat n k _ _) = hcat [ppr n, char '+', ppr k] pprPat (QuasiQuotePat (HsQuasiQuote name quoter _ quote)) = char '$' <> brackets (ppr name) <> - ptext SLIT("[:") <> ppr quoter <> ptext SLIT("|") <> - ppr quote <> ptext SLIT("|]") -pprPat (TypePat ty) = ptext SLIT("{|") <> ppr ty <> ptext SLIT("|}") + 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 @@ -286,18 +304,18 @@ 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} @@ -328,7 +346,7 @@ mkCoPat co pat ty mkCoPatCoI :: CoercionI -> Pat id -> Type -> Pat id mkCoPatCoI IdCo pat _ = pat -mkCoPatCoI (ACo co) pat ty = mkCoPat (WpCo co) pat ty +mkCoPatCoI (ACo co) pat ty = mkCoPat (WpCast co) pat ty \end{code} @@ -398,7 +416,7 @@ isBangHsBind :: HsBind id -> Bool isBangHsBind (PatBind { pat_lhs = L _ (BangPat _) }) = True isBangHsBind _ = False -isIrrefutableHsPat :: LPat id -> Bool +isIrrefutableHsPat :: OutputableBndr id => LPat id -> Bool -- (isIrrefutableHsPat p) is true if matching against p cannot fail, -- in the sense of falling through to the next pattern. -- (NB: this is not quite the same as the (silly) defn @@ -410,12 +428,12 @@ isIrrefutableHsPat :: 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 @@ -424,18 +442,50 @@ 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 (TypePat _) = panic "isIrrefutableHsPat: type pattern" + 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}