#include "HsVersions.h"
import CmdLineOpts ( opt_D_dump_ds )
-import HsSyn ( MonoBinds )
-import TcHsSyn ( TypecheckedMonoBinds, TypecheckedForeignDecl )
+import HsSyn ( MonoBinds, RuleDecl(..), RuleBndr(..), HsExpr(..), HsBinds(..), MonoBinds(..) )
+import HsCore ( UfRuleBody(..) )
+import TcHsSyn ( TypecheckedMonoBinds, TypecheckedForeignDecl, TypecheckedRuleDecl )
+import TcModule ( TcResults(..) )
import CoreSyn
+import Rules ( ProtoCoreRule(..), pprProtoCoreRule )
+import Subst ( substExpr, mkSubst )
import DsMonad
-import DsBinds ( dsMonoBinds )
+import DsExpr ( dsExpr )
+import DsBinds ( dsMonoBinds, AutoScc(..) )
import DsForeign ( dsForeigns )
import DsUtils
import DsExpr () -- Forces DsExpr to be compiled; DsBinds only
-- depends on DsExpr.hi-boot.
-import Name ( Module, moduleString )
+import Module ( Module, moduleString )
+import Id ( Id )
+import Name ( isLocallyDefined )
+import VarEnv
+import VarSet
import Bag ( isEmptyBag, unionBags )
import CmdLineOpts ( opt_SccGroup, opt_SccProfilingOn )
import CoreLint ( beginPass, endPass )
import UniqSupply ( splitUniqSupply, UniqSupply )
\end{code}
+%************************************************************************
+%* *
+%* The main function: deSugar
+%* *
+%************************************************************************
+
The only trick here is to get the @DsMonad@ stuff off to a good
start.
\begin{code}
-deSugar :: UniqSupply -- name supply
- -> ValueEnv -- value env
- -> Module -- module name
- -> TypecheckedMonoBinds
- -> [TypecheckedForeignDecl]
- -> IO ([CoreBind], SDoc, SDoc) -- output
-
-deSugar us global_val_env mod_name all_binds fo_decls = do
+deSugar :: Module
+ -> UniqSupply
+ -> TcResults
+ -> IO ([CoreBind], [ProtoCoreRule], SDoc, SDoc)
+
+deSugar mod_name us (TcResults {tc_env = global_val_env,
+ tc_binds = all_binds,
+ tc_rules = rules,
+ tc_fords = fo_decls})
+ = do
beginPass "Desugar"
-- Do desugaring
- let (core_prs, ds_warns1) = initDs us1 global_val_env module_and_group
- (dsMonoBinds opt_SccProfilingOn all_binds [])
- ds_binds' = [Rec core_prs]
-
- ((fi_binds, fe_binds, h_code, c_code), ds_warns2) =
- initDs us3 global_val_env module_and_group (dsForeigns fo_decls)
-
- ds_binds = fi_binds ++ ds_binds' ++ fe_binds
-
- ds_warns = ds_warns1 `unionBags` ds_warns2
+ let (result, ds_warns) = initDs us global_val_env module_and_group
+ (dsProgram mod_name all_binds rules fo_decls)
+ (ds_binds, ds_rules, _, _) = result
-- Display any warnings
doIfSet (not (isEmptyBag ds_warns))
-- Lint result if necessary
endPass "Desugar" opt_D_dump_ds ds_binds
- return (ds_binds, h_code, c_code)
- where
- (us1, us2) = splitUniqSupply us
- (us3, us4) = splitUniqSupply us2
+ doIfSet opt_D_dump_ds (printDump (ppr_ds_rules ds_rules))
+
+ return result
+ where
module_and_group = (mod_name, grp_name)
grp_name = case opt_SccGroup of
Just xx -> _PK_ xx
- Nothing -> _PK_ (moduleString mod_name) -- default: module name
+ Nothing -> _PK_ (moduleString mod_name) -- default: module name
+
+dsProgram mod_name all_binds rules fo_decls
+ = dsMonoBinds auto_scc all_binds [] `thenDs` \ core_prs ->
+ dsForeigns mod_name fo_decls `thenDs` \ (fi_binds, fe_binds, h_code, c_code) ->
+ mapDs dsRule rules `thenDs` \ rules' ->
+ let
+ ds_binds = fi_binds ++ [Rec core_prs] ++ fe_binds
+ in
+ returnDs (ds_binds, rules', h_code, c_code)
+ where
+ auto_scc | opt_SccProfilingOn = TopLevel
+ | otherwise = NoSccs
+
+ppr_ds_rules [] = empty
+ppr_ds_rules rules
+ = text "" $$ text "-------------- DESUGARED RULES -----------------" $$
+ vcat (map pprProtoCoreRule rules)
+\end{code}
+
+
+%************************************************************************
+%* *
+%* Desugaring transformation rules
+%* *
+%************************************************************************
+
+\begin{code}
+dsRule :: TypecheckedRuleDecl -> DsM ProtoCoreRule
+dsRule (IfaceRuleDecl fn (CoreRuleBody name all_vars args rhs) loc)
+ = returnDs (ProtoCoreRule False {- non-local -} fn
+ (Rule name all_vars args rhs))
+
+dsRule (RuleDecl name sig_tvs vars lhs rhs loc)
+ = putSrcLocDs loc $
+ ds_lhs all_vars lhs `thenDs` \ (fn, args) ->
+ dsExpr rhs `thenDs` \ core_rhs ->
+ returnDs (ProtoCoreRule True {- local -} fn
+ (Rule name all_vars args core_rhs))
+ where
+ all_vars = sig_tvs ++ [var | RuleBndr var <- vars]
+
+ds_lhs all_vars lhs
+ = let
+ (dict_binds, body) = case lhs of
+ (HsLet (MonoBind dict_binds _ _) body) -> (dict_binds, body)
+ other -> (EmptyMonoBinds, lhs)
+ in
+ ds_dict_binds dict_binds `thenDs` \ dict_binds' ->
+ dsExpr body `thenDs` \ body' ->
+
+ -- Substitute the dict bindings eagerly,
+ -- and take the body apart into a (f args) form
+ let
+ subst_env = mkSubstEnv [id | (id,rhs) <- dict_binds']
+ [ContEx subst_env rhs | (id,rhs) <- dict_binds']
+ -- Note recursion here... substitution won't terminate
+ -- if there is genuine recursion... which there isn't
+
+ subst = mkSubst (mkVarSet all_vars) subst_env
+ body'' = substExpr subst body'
+ in
+
+ -- Now unpack the resulting body
+ let
+ pair = case collectArgs body'' of
+ (Var fn, args) -> (fn, args)
+ other -> pprPanic "dsRule" (ppr lhs)
+ in
+ returnDs pair
+ds_dict_binds EmptyMonoBinds = returnDs []
+ds_dict_binds (AndMonoBinds b1 b2) = ds_dict_binds b1 `thenDs` \ env1 ->
+ ds_dict_binds b2 `thenDs` \ env2 ->
+ returnDs (env1 ++ env2)
+ds_dict_binds (VarMonoBind id rhs) = dsExpr rhs `thenDs` \ rhs' ->
+ returnDs [(id,rhs')]
\end{code}