import DsUtils
import DsArrows
import DsMonad
+import Name
#ifdef GHCI
import PrelNames
-import DsBreakpoint
-- Template Haskell stuff iff bootstrapped
import DsMeta
-#else
-import DsBreakpoint
#endif
import HsSyn
import Id
import PrelInfo
import DataCon
-import TyCon
import TysWiredIn
import BasicTypes
import PrelNames
import Bag
import Outputable
import FastString
-
-import Data.Maybe
\end{code}
\begin{code}
dsLExpr :: LHsExpr Id -> DsM CoreExpr
-#if defined(GHCI)
-dsLExpr (L loc expr@(HsWrap w (HsVar v)))
- | idName v `elem` [breakpointName, breakpointCondName, breakpointAutoName]
- , WpTyApp ty <- simpWrapper w
- = do areBreakpointsEnabled <- breakpoints_enabled
- if areBreakpointsEnabled
- then do
- L _ breakpointExpr <- mkBreakpointExpr loc v ty
- dsLExpr (L loc $ HsWrap w breakpointExpr)
- else putSrcSpanDs loc $ dsExpr expr
- where simpWrapper (WpCompose w1 WpHole) = w1
- simpWrapper (WpCompose WpHole w1) = w1
- simpWrapper w = w
-#endif
-
dsLExpr (L loc e) = putSrcSpanDs loc $ dsExpr e
dsExpr :: HsExpr Id -> DsM CoreExpr
dsExpr expr@(HsApp fun arg)
= dsLExpr fun `thenDs` \ core_fun ->
dsLExpr arg `thenDs` \ core_arg ->
- returnDs (core_fun `App` core_arg)
+ returnDs (core_fun `mkDsApp` core_arg)
\end{code}
Operator sections. At first it looks as if we can convert
-- for the type of y, we need the type of op's 2nd argument
dsLExpr e1 `thenDs` \ x_core ->
dsLExpr e2 `thenDs` \ y_core ->
- returnDs (mkApps core_op [x_core, y_core])
+ returnDs (mkDsApps core_op [x_core, y_core])
dsExpr (SectionL expr op) -- Desugar (e !) to ((!) e)
= dsLExpr op `thenDs` \ core_op ->
dsLExpr expr `thenDs` \ x_core ->
- returnDs (App core_op x_core)
+ returnDs (mkDsApp core_op x_core)
-- dsLExpr (SectionR op expr) -- \ x -> op x expr
dsExpr (SectionR op expr)
newSysLocalDs y_ty `thenDs` \ y_id ->
returnDs (bindNonRec y_id y_core $
- Lam x_id (mkApps core_op [Var x_id, Var y_id]))
+ Lam x_id (mkDsApps core_op [Var x_id, Var y_id]))
dsExpr (HsSCC cc expr)
= dsLExpr expr `thenDs` \ core_expr ->
-- Pepe: The binds are in scope in the body but NOT in the binding group
-- This is to avoid silliness in breakpoints
dsExpr (HsLet binds body)
- = (bindLocalsDs (map unLoc $ collectLocalBinders binds) $
- dsAndThenMaybeInsertBreakpoint body) `thenDs` \ body' ->
+ = dsLExpr body `thenDs` \ body' ->
dsLocalBinds binds body'
-- We need the `ListComp' form to use `deListComp' (rather than the "do" form)
-- hence TcType.tcSplitFunTys
mk_arg (arg_ty, lbl) -- Selector id has the field label as its name
- = case [rhs | (L _ sel_id, rhs) <- rbinds, lbl == idName sel_id] of
+ = case findField (rec_flds rbinds) lbl of
(rhs:rhss) -> ASSERT( null rhss )
dsLExpr rhs
[] -> mkErrorAppDs rEC_CON_ERROR_ID arg_ty (showSDoc (ppr lbl))
dictionaries.
\begin{code}
-dsExpr (RecordUpd record_expr [] record_in_ty record_out_ty)
+dsExpr expr@(RecordUpd record_expr (HsRecFields { rec_flds = fields })
+ cons_to_upd in_inst_tys out_inst_tys)
+ | null fields
= dsLExpr record_expr
-
-dsExpr expr@(RecordUpd record_expr rbinds record_in_ty record_out_ty)
- = dsLExpr record_expr `thenDs` \ record_expr' ->
-
- -- Desugar the rbinds, and generate let-bindings if
- -- necessary so that we don't lose sharing
-
- let
- in_inst_tys = tcTyConAppArgs record_in_ty -- Newtype opaque
- out_inst_tys = tcTyConAppArgs record_out_ty -- Newtype opaque
- in_out_ty = mkFunTy record_in_ty record_out_ty
-
- mk_val_arg field old_arg_id
- = case [rhs | (L _ sel_id, rhs) <- rbinds, field == idName sel_id] of
- (rhs:rest) -> ASSERT(null rest) rhs
- [] -> nlHsVar old_arg_id
-
- mk_alt con
- = ASSERT( isVanillaDataCon con )
- newSysLocalsDs (dataConInstOrigArgTys con in_inst_tys) `thenDs` \ arg_ids ->
- -- This call to dataConInstOrigArgTys won't work for existentials
- -- but existentials don't have record types anyway
- let
- val_args = zipWithEqual "dsExpr:RecordUpd" mk_val_arg
- (dataConFieldLabels con) arg_ids
- rhs = foldl (\a b -> nlHsApp a b)
- (nlHsTyApp (dataConWrapId con) out_inst_tys)
- val_args
- in
- returnDs (mkSimpleMatch [mkPrefixConPat con (map nlVarPat arg_ids) record_in_ty] rhs)
- in
- -- Record stuff doesn't work for existentials
+ | otherwise
+ = -- Record stuff doesn't work for existentials
-- The type checker checks for this, but we need
-- worry only about the constructors that are to be updated
- ASSERT2( all isVanillaDataCon cons_to_upd, ppr expr )
+ ASSERT2( notNull cons_to_upd && all isVanillaDataCon cons_to_upd, ppr expr )
+
+ do { record_expr' <- dsLExpr record_expr
+ ; let -- Awkwardly, for families, the match goes
+ -- from instance type to family type
+ tycon = dataConTyCon (head cons_to_upd)
+ in_ty = mkTyConApp tycon in_inst_tys
+ in_out_ty = mkFunTy in_ty
+ (mkFamilyTyConApp tycon out_inst_tys)
+
+ mk_val_arg field old_arg_id
+ = case findField fields field of
+ (rhs:rest) -> ASSERT(null rest) rhs
+ [] -> nlHsVar old_arg_id
+
+ mk_alt con
+ = ASSERT( isVanillaDataCon con )
+ do { arg_ids <- newSysLocalsDs (dataConInstOrigArgTys con in_inst_tys)
+ -- This call to dataConInstOrigArgTys won't work for existentials
+ -- but existentials don't have record types anyway
+ ; let val_args = zipWithEqual "dsExpr:RecordUpd" mk_val_arg
+ (dataConFieldLabels con) arg_ids
+ rhs = foldl (\a b -> nlHsApp a b)
+ (nlHsTyApp (dataConWrapId con) out_inst_tys)
+ val_args
+ pat = mkPrefixConPat con (map nlVarPat arg_ids) in_ty
+
+ ; return (mkSimpleMatch [pat] rhs) }
-- It's important to generate the match with matchWrapper,
-- and the right hand sides with applications of the wrapper Id
-- so that everything works when we are doing fancy unboxing on the
-- constructor aguments.
- mappM mk_alt cons_to_upd `thenDs` \ alts ->
- matchWrapper RecUpd (MatchGroup alts in_out_ty) `thenDs` \ ([discrim_var], matching_code) ->
-
- returnDs (bindNonRec discrim_var record_expr' matching_code)
+ ; alts <- mapM mk_alt cons_to_upd
+ ; ([discrim_var], matching_code) <- matchWrapper RecUpd (MatchGroup alts in_out_ty)
- where
- updated_fields :: [FieldLabel]
- updated_fields = [ idName sel_id | (L _ sel_id,_) <- rbinds]
-
- -- Get the type constructor from the record_in_ty
- -- so that we are sure it'll have all its DataCons
- -- (In GHCI, it's possible that some TyCons may not have all
- -- their constructors, in a module-loop situation.)
- tycon = tcTyConAppTyCon record_in_ty
- data_cons = tyConDataCons tycon
- cons_to_upd = filter has_all_fields data_cons
-
- has_all_fields :: DataCon -> Bool
- has_all_fields con_id
- = all (`elem` con_fields) updated_fields
- where
- con_fields = dataConFieldLabels con_id
+ ; return (bindNonRec discrim_var record_expr' matching_code) }
\end{code}
Here is where we desugar the Template Haskell brackets and escapes
Hpc Support
\begin{code}
-dsExpr (HsTick ix e) = do
+dsExpr (HsTick ix vars e) = do
e' <- dsLExpr e
- mkTickBox ix e'
+ mkTickBox ix vars e'
-- There is a problem here. The then and else branches
-- have no free variables, so they are open to lifting.
dsExpr (ExprWithTySig _ _) = panic "dsExpr:ExprWithTySig"
#endif
+
+findField :: [HsRecField Id arg] -> Name -> [arg]
+findField rbinds lbl
+ = [rhs | HsRecField { hsRecFieldId = id, hsRecFieldArg = rhs } <- rbinds
+ , lbl == idName (unLoc id) ]
\end{code}
%--------------------------------------------------------------------
dsDo stmts body result_ty
= go (map unLoc stmts)
where
- go [] = dsAndThenMaybeInsertBreakpoint body
+ go [] = dsLExpr body
go (ExprStmt rhs then_expr _ : stmts)
- = do { rhs2 <- dsAndThenMaybeInsertBreakpoint rhs
+ = do { rhs2 <- dsLExpr rhs
; then_expr2 <- dsExpr then_expr
; rest <- go stmts
; returnDs (mkApps then_expr2 [rhs2, rest]) }
go (LetStmt binds : stmts)
- = do { rest <- bindLocalsDs (map unLoc$ collectLocalBinders binds) $
- go stmts
+ = do { rest <- go stmts
; dsLocalBinds binds rest }
- -- Notice how due to the placement of bindLocals, binders in this stmt
- -- are available in posterior stmts but Not in this one rhs.
- -- This is to avoid silliness in breakpoints
go (BindStmt pat rhs bind_op fail_op : stmts)
=
- do { body <- bindLocalsDs (collectPatBinders pat) $ go stmts
+ do { body <- go stmts
; var <- selectSimpleMatchVarL pat
; match <- matchSinglePat (Var var) (StmtCtxt DoExpr) pat
result_ty (cantFailMatchResult body)
; match_code <- handle_failure pat match fail_op
- ; rhs' <- dsAndThenMaybeInsertBreakpoint rhs
+ ; rhs' <- dsLExpr rhs
; bind_op' <- dsExpr bind_op
; returnDs (mkApps bind_op' [rhs', Lam var match_code]) }
; dsLocalBinds binds rest }
go (ExprStmt rhs _ rhs_ty : stmts)
- = do { rhs2 <- dsAndThenMaybeInsertBreakpoint rhs
+ = do { rhs2 <- dsLExpr rhs
; rest <- go stmts
; returnDs (mkApps (Var then_id) [Type rhs_ty, Type b_ty, rhs2, rest]) }
go (BindStmt pat rhs _ _ : stmts)
- = do { body <- bindLocalsDs (collectPatBinders pat) $ go stmts
+ = do { body <- go stmts
; var <- selectSimpleMatchVarL pat
; match <- matchSinglePat (Var var) (StmtCtxt ctxt) pat
result_ty (cantFailMatchResult body)
; let fail_expr = mkApps (Var fail_id) [Type b_ty, fail_msg]
; match_code <- extractMatchResult match fail_expr
- ; rhs' <- dsAndThenMaybeInsertBreakpoint rhs
+ ; rhs' <- dsLExpr rhs
; returnDs (mkApps (Var bind_id) [Type (hsLPatType pat), Type b_ty,
rhs', Lam var match_code]) }