%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1996
+% (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
%
\section[PrefixToHS]{Support routines for converting ``prefix form'' to Haskell abstract syntax}
Support routines for reading prefix-form from the Lex/Yacc parser.
\begin{code}
-#include "HsVersions.h"
-
module PrefixToHs (
- cvValSig,
- cvClassOpSig,
- cvInstDeclSig,
cvBinds,
- cvMatches,
- cvMonoBinds,
- cvSepdBinds,
- sepDeclsForTopBinds,
- sepDeclsIntoSigsAndBinds
+ cvMonoBindsAndSigs,
+ cvTopDecls,
+ cvValSig, cvClassOpSig, cvInstDeclSig
) where
-import Ubiq{-uitous-}
+#include "HsVersions.h"
import PrefixSyn -- and various syntaxen.
import HsSyn
import RdrHsSyn
-import HsPragmas ( noGenPragmas, noClassOpPragmas )
-import SrcLoc ( mkSrcLoc2 )
-import Util ( panic, assertPanic )
+import BasicTypes ( RecFlag(..) )
+import SrcLoc ( mkSrcLoc )
+import Util ( mapAndUnzip )
+import Panic ( panic, assertPanic )
\end{code}
%************************************************************************
We make a point not to throw any user-pragma ``sigs'' at
these conversion functions:
+
\begin{code}
cvValSig, cvClassOpSig, cvInstDeclSig :: SigConverter
-cvValSig (RdrTySig vars poly_ty src_loc)
- = [ Sig v poly_ty noGenPragmas src_loc | v <- vars ]
+cvValSig sig = sig
-cvClassOpSig (RdrTySig vars poly_ty src_loc)
- = [ ClassOpSig v poly_ty noClassOpPragmas src_loc | v <- vars ]
+cvInstDeclSig sig = sig
-cvInstDeclSig (RdrSpecValSig sigs) = sigs
-cvInstDeclSig (RdrInlineValSig sig) = [ sig ]
-cvInstDeclSig (RdrDeforestSig sig) = [ sig ]
-cvInstDeclSig (RdrMagicUnfoldingSig sig) = [ sig ]
+cvClassOpSig (Sig var poly_ty src_loc) = ClassOpSig var Nothing poly_ty src_loc
+cvClassOpSig sig = sig
\end{code}
+
%************************************************************************
%* *
\subsection[cvBinds-etc]{Converting to @HsBinds@, @MonoBinds@, etc.}
\begin{code}
cvBinds :: SrcFile -> SigConverter -> RdrBinding -> RdrNameHsBinds
-cvBinds sf sig_cvtr raw_binding
- = cvSepdBinds sf sig_cvtr (sepDeclsForBinds raw_binding)
-
-cvSepdBinds :: SrcFile -> SigConverter -> [RdrBinding] -> RdrNameHsBinds
-cvSepdBinds sf sig_cvtr bindings
- = case (mkMonoBindsAndSigs sf sig_cvtr bindings) of { (mbs, sigs) ->
- if (null sigs)
- then SingleBind (RecBind mbs)
- else BindWith (RecBind mbs) sigs
- }
+ -- The mysterious SigConverter converts Sigs to ClassOpSigs
+ -- in class declarations. Mostly it's just an identity function
-cvMonoBinds :: SrcFile -> [RdrBinding] -> RdrNameMonoBinds
-cvMonoBinds sf bindings
- = case (mkMonoBindsAndSigs sf bottom bindings) of { (mbs,sigs) ->
- if (null sigs)
- then mbs
- else panic "cvMonoBinds: some sigs present"
+cvBinds sf sig_cvtr binding
+ = case (cvMonoBindsAndSigs sf sig_cvtr binding) of { (mbs, sigs) ->
+ MonoBind mbs sigs Recursive
}
- where
- bottom = panic "cvMonoBinds: sig converter!"
\end{code}
\begin{code}
-mkMonoBindsAndSigs :: SrcFile
+cvMonoBindsAndSigs :: SrcFile
-> SigConverter
- -> [RdrBinding]
+ -> RdrBinding
-> (RdrNameMonoBinds, [RdrNameSig])
-mkMonoBindsAndSigs sf sig_cvtr fbs
- = foldl mangle_bind (EmptyMonoBinds, []) fbs
+cvMonoBindsAndSigs sf sig_cvtr fb
+ = mangle_bind (EmptyMonoBinds, []) fb
where
- -- If the function being bound has at least one argument, then the
- -- guarded right hand sides of each pattern binding are knitted
- -- into a series of patterns, each matched with its corresponding
- -- guarded right hand side (which may contain several
- -- alternatives). This series is then paired with the name of the
- -- function. Otherwise there is only one pattern, which is paired
- -- with a guarded right hand side.
-
- mangle_bind (b_acc, s_acc) sig@(RdrTySig _ _ _)
- = (b_acc, s_acc ++ sig_cvtr sig)
-
- mangle_bind (b_acc, s_acc) (RdrSpecValSig sig) = (b_acc, sig ++ s_acc)
- mangle_bind (b_acc, s_acc) (RdrInlineValSig sig) = (b_acc, sig : s_acc)
- mangle_bind (b_acc, s_acc) (RdrDeforestSig sig) = (b_acc, sig : s_acc)
- mangle_bind (b_acc, s_acc) (RdrMagicUnfoldingSig sig) = (b_acc, sig : s_acc)
-
- mangle_bind (b_acc, s_acc)
- (RdrPatternBinding lousy_srcline [patbinding])
- -- WDP: the parser has trouble getting a good line-number on RdrPatternBindings.
- = case (cvPatMonoBind sf patbinding) of { (pat, grhss, binds) ->
- let
- src_loc = mkSrcLoc2 sf good_srcline
- in
- (b_acc `AndMonoBinds`
- PatMonoBind pat (GRHSsAndBindsIn grhss binds) src_loc, s_acc)
- }
- where
- good_srcline = case patbinding of
- RdrMatch_NoGuard ln _ _ _ _ -> ln
- RdrMatch_Guards ln _ _ _ _ -> ln
+ mangle_bind acc RdrNullBind
+ = acc
+ mangle_bind acc (RdrAndBindings fb1 fb2)
+ = mangle_bind (mangle_bind acc fb1) fb2
- mangle_bind _ (RdrPatternBinding _ _)
- = panic "mangleBinding: more than one pattern on a RdrPatternBinding"
+ mangle_bind (b_acc, s_acc) (RdrSig sig)
+ = (b_acc, sig_cvtr sig : s_acc)
- mangle_bind (b_acc, s_acc) (RdrFunctionBinding srcline patbindings)
- -- must be a function binding...
- = case (cvFunMonoBind sf patbindings) of { (var, inf, matches) ->
- (b_acc `AndMonoBinds`
- FunMonoBind var inf matches (mkSrcLoc2 sf srcline), s_acc)
- }
+ mangle_bind (b_acc, s_acc) (RdrValBinding binding)
+ = (b_acc `AndMonoBinds` binding, s_acc)
\end{code}
-\begin{code}
-cvPatMonoBind :: SrcFile -> RdrMatch -> (RdrNamePat, [RdrNameGRHS], RdrNameHsBinds)
-
-cvPatMonoBind sf (RdrMatch_NoGuard srcline srcfun pat expr binding)
- = (pat, [OtherwiseGRHS expr (mkSrcLoc2 sf srcline)], cvBinds sf cvValSig binding)
-
-cvPatMonoBind sf (RdrMatch_Guards srcline srcfun pat guardedexprs binding)
- = (pat, map (cvGRHS sf srcline) guardedexprs, cvBinds sf cvValSig binding)
-
-cvFunMonoBind :: SrcFile -> [RdrMatch] -> (RdrName {-VarName-}, Bool {-InfixDefn-}, [RdrNameMatch])
-
-cvFunMonoBind sf matches
- = (head srcfuns, head infixdefs, cvMatches sf False matches)
- where
- (srcfuns, infixdefs) = unzip (map get_mdef matches)
- -- ToDo: Check for consistent srcfun and infixdef
-
- get_mdef (RdrMatch_NoGuard _ sfun pat _ _) = get_pdef pat
- get_mdef (RdrMatch_Guards _ sfun pat _ _) = get_pdef pat
-
- get_pdef (ConPatIn fn _) = (fn, False)
- get_pdef (ConOpPatIn _ op _) = (op, True)
- get_pdef (ParPatIn pat) = get_pdef pat
-
-
-cvMatches :: SrcFile -> Bool -> [RdrMatch] -> [RdrNameMatch]
-cvMatch :: SrcFile -> Bool -> RdrMatch -> RdrNameMatch
-
-cvMatches sf is_case matches = map (cvMatch sf is_case) matches
-
-cvMatch sf is_case rdr_match
- = foldr PatMatch
- (GRHSMatch (GRHSsAndBindsIn guarded_exprs (cvBinds sf cvValSig binding)))
-
- -- For a FunMonoBinds, the first flattened "pattern" is
- -- just the function name, and we don't want to keep it.
- -- For a case expr, it's (presumably) a constructor name -- and
- -- we most certainly want to keep it! Hence the monkey busines...
-
- (if is_case then -- just one pattern: leave it untouched...
- [pat]
- else -- function pattern; extract arg patterns...
- case pat of ConPatIn fn pats -> pats
- ConOpPatIn p1 op p2 -> [p1,p2]
- ParPatIn pat -> panic "PrefixToHs.cvMatch:ParPatIn"
- )
- where
- (pat, binding, guarded_exprs)
- = case rdr_match of
- RdrMatch_NoGuard ln b c expr d -> (c,d, [OtherwiseGRHS expr (mkSrcLoc2 sf ln)])
- RdrMatch_Guards ln b c gd_exps d -> (c,d, map (cvGRHS sf ln) gd_exps)
-
-cvGRHS :: SrcFile -> SrcLine -> (RdrNameHsExpr, RdrNameHsExpr) -> RdrNameGRHS
-cvGRHS sf sl (g, e) = GRHS g e (mkSrcLoc2 sf sl)
-\end{code}
%************************************************************************
%* *
%************************************************************************
Separate declarations into all the various kinds:
-\begin{display}
-tys RdrTyDecl
-ty "sigs" RdrSpecDataSig
-classes RdrClassDecl
-insts RdrInstDecl
-inst "sigs" RdrSpecInstSig
-defaults RdrDefaultDecl
-binds RdrFunctionBinding RdrPatternBinding RdrTySig
- RdrSpecValSig RdrInlineValSig RdrDeforestSig
- RdrMagicUnfoldingSig
-\end{display}
-
-This function isn't called directly; some other function calls it,
-then checks that what it got is appropriate for that situation.
-(Those functions follow...)
\begin{code}
-sepDecls (RdrTyDecl a)
- tys tysigs classes insts instsigs defaults binds
- = (a:tys,tysigs,classes,insts,instsigs,defaults,binds)
-
-sepDecls a@(RdrFunctionBinding _ _)
- tys tysigs classes insts instsigs defaults binds
- = (tys,tysigs,classes,insts,instsigs,defaults,a:binds)
-
-sepDecls a@(RdrPatternBinding _ _)
- tys tysigs classes insts instsigs defaults binds
- = (tys,tysigs,classes,insts,instsigs,defaults,a:binds)
-
--- RdrAndBindings catered for below...
-
-sepDecls (RdrClassDecl a)
- tys tysigs classes insts instsigs defaults binds
- = (tys,tysigs,a:classes,insts,instsigs,defaults,binds)
-
-sepDecls (RdrInstDecl a)
- tys tysigs classes insts instsigs defaults binds
- = (tys,tysigs,classes,a:insts,instsigs,defaults,binds)
-
-sepDecls (RdrDefaultDecl a)
- tys tysigs classes insts instsigs defaults binds
- = (tys,tysigs,classes,insts,instsigs,a:defaults,binds)
-
-sepDecls a@(RdrTySig _ _ _)
- tys tysigs classes insts instsigs defaults binds
- = (tys,tysigs,classes,insts,instsigs,defaults,a:binds)
-
-sepDecls a@(RdrSpecValSig _)
- tys tysigs classes insts instsigs defaults binds
- = (tys,tysigs,classes,insts,instsigs,defaults,a:binds)
-
-sepDecls a@(RdrInlineValSig _)
- tys tysigs classes insts instsigs defaults binds
- = (tys,tysigs,classes,insts,instsigs,defaults,a:binds)
-
-sepDecls a@(RdrDeforestSig _)
- tys tysigs classes insts instsigs defaults binds
- = (tys,tysigs,classes,insts,instsigs,defaults,a:binds)
-
-sepDecls a@(RdrMagicUnfoldingSig _)
- tys tysigs classes insts instsigs defaults binds
- = (tys,tysigs,classes,insts,instsigs,defaults,a:binds)
-
-sepDecls (RdrSpecInstSig a)
- tys tysigs classes insts instsigs defaults binds
- = (tys,tysigs,classes,insts,a:instsigs,defaults,binds)
-
-sepDecls (RdrSpecDataSig a)
- tys tysigs classes insts instsigs defaults binds
- = (tys,a:tysigs,classes,insts,instsigs,defaults,binds)
-
-sepDecls RdrNullBind
- tys tysigs classes insts instsigs defaults binds
- = (tys,tysigs,classes,insts,instsigs,defaults,binds)
-
-sepDecls (RdrAndBindings bs1 bs2)
- tys tysigs classes insts instsigs defaults binds
- = case (sepDecls bs2 tys tysigs classes insts instsigs defaults binds) of {
- (tys,tysigs,classes,insts,instsigs,defaults,binds) ->
- sepDecls bs1 tys tysigs classes insts instsigs defaults binds
- }
-\end{code}
-
-\begin{code}
-sepDeclsForTopBinds binding
- = sepDecls binding [] [] [] [] [] [] []
-
-sepDeclsForBinds binding
- = case (sepDecls binding [] [] [] [] [] [] [])
- of { (tys,tysigs,classes,insts,instsigs,defaults,binds) ->
- ASSERT ((null tys)
- && (null tysigs)
- && (null classes)
- && (null insts)
- && (null instsigs)
- && (null defaults))
- binds
- }
-
-sepDeclsIntoSigsAndBinds binding
- = case (sepDeclsForBinds binding) of { sigs_and_binds ->
- foldr sep_stuff ([],[]) sigs_and_binds
- }
+cvTopDecls :: SrcFile -> RdrBinding -> [RdrNameHsDecl]
+cvTopDecls srcfile bind
+ = let
+ (top_decls, mono_binds, sigs) = go ([], EmptyMonoBinds, []) bind
+ in
+ (ValD (MonoBind mono_binds sigs Recursive) : top_decls)
where
- sep_stuff s@(RdrTySig _ _ _) (sigs,defs) = (s:sigs,defs)
- sep_stuff s@(RdrSpecValSig _) (sigs,defs) = (s:sigs,defs)
- sep_stuff s@(RdrInlineValSig _) (sigs,defs) = (s:sigs,defs)
- sep_stuff s@(RdrDeforestSig _) (sigs,defs) = (s:sigs,defs)
- sep_stuff s@(RdrMagicUnfoldingSig _) (sigs,defs) = (s:sigs,defs)
- sep_stuff d@(RdrFunctionBinding _ _) (sigs,defs) = (sigs,d:defs)
- sep_stuff d@(RdrPatternBinding _ _) (sigs,defs) = (sigs,d:defs)
-
-
+ go acc RdrNullBind = acc
+ go acc (RdrAndBindings b1 b2) = go (go acc b1) b2
+ go (topds, mbs, sigs) (RdrHsDecl d) = (d : topds, mbs, sigs)
+ go (topds, mbs, sigs) (RdrSig (FixSig d)) = (FixD d : topds, mbs, sigs)
+ go (topds, mbs, sigs) (RdrSig sig) = (topds, mbs, sig:sigs)
+ go (topds, mbs, sigs) (RdrValBinding bind) = (topds, mbs `AndMonoBinds` bind, sigs)
\end{code}