X-Git-Url: http://git.megacz.com/?p=coq-hetmet.git;a=blobdiff_plain;f=src%2FHaskWeak.v;h=077f7b509a22032859a83729226a7fc82b2620fe;hp=a9f8bb66f10529794544c68019ec9a50fdbfa414;hb=1a2754d2e135ef3c5fd7ef817e1129af93b533a5;hpb=703bff3b209bd7d114b49cb736da8af167a4ec71 diff --git a/src/HaskWeak.v b/src/HaskWeak.v index a9f8bb6..077f7b5 100644 --- a/src/HaskWeak.v +++ b/src/HaskWeak.v @@ -6,163 +6,106 @@ Generalizable All Variables. Require Import Preamble. Require Import General. Require Import Coq.Lists.List. -Require Import HaskGeneral. +Require Import HaskKinds. Require Import HaskLiterals. +Require Import HaskTyCons. Require Import HaskCoreVars. -Require Import HaskCoreTypes. -Require Import HaskCoreTypes. Require Import HaskWeakVars. +Require Import HaskWeakTypes. + +Inductive WeakAltCon := +| WeakDataAlt : CoreDataCon -> WeakAltCon +| WeakLitAlt : HaskLiteral -> WeakAltCon +| WeakDEFAULT : WeakAltCon. Inductive WeakExpr := | WEVar : WeakExprVar -> WeakExpr | WELit : HaskLiteral -> WeakExpr + +(* TO DO: add a WEWhere and use the source location to detect which one the user used *) | WELet : WeakExprVar -> WeakExpr -> WeakExpr -> WeakExpr | WELetRec : Tree ??(WeakExprVar * WeakExpr) -> WeakExpr -> WeakExpr | WECast : WeakExpr -> WeakCoercion -> WeakExpr | WENote : Note -> WeakExpr -> WeakExpr | WEApp : WeakExpr -> WeakExpr -> WeakExpr -| WETyApp : WeakExpr -> CoreType -> WeakExpr +| WETyApp : WeakExpr -> WeakType -> WeakExpr | WECoApp : WeakExpr -> WeakCoercion -> WeakExpr | WELam : WeakExprVar -> WeakExpr -> WeakExpr | WETyLam : WeakTypeVar -> WeakExpr -> WeakExpr | WECoLam : WeakCoerVar -> WeakExpr -> WeakExpr -(* the CoreType argument is used only when going back from Weak to Core; it lets us dodge a possibly-failing type calculation *) -| WEBrak : WeakTypeVar -> WeakExpr -> CoreType -> WeakExpr -| WEEsc : WeakTypeVar -> WeakExpr -> CoreType -> WeakExpr +(* The WeakType argument in WEBrak/WEEsc is used only when going back *) +(* from Weak to Core; it lets us dodge a possibly-failing type *) +(* calculation. The CoreVar argument is the GlobalVar for the hetmet_brak *) +(* or hetmet_esc identifier *) +| WEBrak : WeakExprVar -> WeakTypeVar -> WeakExpr -> WeakType -> WeakExpr +| WEEsc : WeakExprVar -> WeakTypeVar -> WeakExpr -> WeakType -> WeakExpr +| WECSP : WeakExprVar -> WeakTypeVar -> WeakExpr -> WeakType -> WeakExpr -(* note that HaskWeak "Case" does not bind a variable; coreExprToWeakExpr adds a let-binder *) -| WECase : forall (scrutinee:WeakExpr) - (tbranches:CoreType) - {n:nat}(tc:TyCon n) - (type_params:vec CoreType n) - (alts : Tree ??(AltCon*list WeakVar*WeakExpr)), +| WECase : forall (vscrut:WeakExprVar) + (scrutinee:WeakExpr) + (tbranches:WeakType) + (tc:TyCon) + (type_params:list WeakType) + (alts : Tree ??(WeakAltCon*list WeakTypeVar*list WeakCoerVar*list WeakExprVar*WeakExpr)), WeakExpr. -(* calculate the free WeakVar's in a WeakExpr *) -Fixpoint getWeakExprFreeVars (me:WeakExpr) : list WeakExprVar := - match me with - | WELit _ => nil - | WEVar cv => cv::nil - | WECast e co => getWeakExprFreeVars e - | WENote n e => getWeakExprFreeVars e - | WETyApp e t => getWeakExprFreeVars e - | WECoApp e co => getWeakExprFreeVars e - | WEBrak ec e _ => getWeakExprFreeVars e - | WEEsc ec e _ => getWeakExprFreeVars e - | WELet cv e1 e2 => mergeDistinctLists (getWeakExprFreeVars e1) (removeFromDistinctList cv (getWeakExprFreeVars e2)) - | WEApp e1 e2 => mergeDistinctLists (getWeakExprFreeVars e1) (getWeakExprFreeVars e2) - | WELam cv e => @removeFromDistinctList _ WeakExprVarEqDecidable cv (getWeakExprFreeVars e) - | WETyLam cv e => getWeakExprFreeVars e - | WECoLam cv e => getWeakExprFreeVars e +Definition weakTypeOfLiteral (lit:HaskLiteral) : WeakType := + (WTyCon (haskLiteralToTyCon lit)). - (* the messy fixpoints below are required by Coq's termination conditions *) - | WECase scrutinee tbranches n tc type_params alts => - mergeDistinctLists (getWeakExprFreeVars scrutinee) ( - ((fix getWeakExprFreeVarsAlts (alts:Tree ??(AltCon*list WeakVar*WeakExpr)) {struct alts} : list WeakExprVar := - match alts with - | T_Leaf None => nil - | T_Leaf (Some (DEFAULT,_,e)) => getWeakExprFreeVars e - | T_Leaf (Some (LitAlt lit,_,e)) => getWeakExprFreeVars e - | T_Leaf (Some (DataAlt _ _ _ _ _ dc, vars,e)) => removeFromDistinctList' - (General.filter (map (fun v => match v with - | WExprVar ev => Some ev - | WTypeVar _ => None - | WCoerVar _ => None - end) vars)) - (getWeakExprFreeVars e) - | T_Branch b1 b2 => mergeDistinctLists (getWeakExprFreeVarsAlts b1) (getWeakExprFreeVarsAlts b2) - end) alts)) - | WELetRec mlr e => (fix removeVarsLetRec (mlr:Tree ??(WeakExprVar * WeakExpr))(cvl:list WeakExprVar) := - match mlr with - | T_Leaf None => cvl - | T_Leaf (Some (cv,e)) => removeFromDistinctList cv cvl - | T_Branch b1 b2 => removeVarsLetRec b1 (removeVarsLetRec b2 cvl) - end) mlr (mergeDistinctLists (getWeakExprFreeVars e) - ((fix getWeakExprFreeVarsLetRec (mlr:Tree ??(WeakExprVar * WeakExpr)) := - match mlr with - | T_Leaf None => nil - | T_Leaf (Some (cv,e)) => getWeakExprFreeVars e - | T_Branch b1 b2 => mergeDistinctLists (getWeakExprFreeVarsLetRec b1) (getWeakExprFreeVarsLetRec b2) - end) mlr)) +(* +Fixpoint weakExprVarOccursFree (wvf:WeakExprVar)(we:WeakExpr) : bool := + match we with + | WEVar wv => if eqd_dec (wvf:CoreVar) (wv:CoreVar) then true else false + | WELit lit => false + | WEApp e1 e2 => weakExprVarOccursFree wvf e1 || weakExprVarOccursFree wvf e2 + | WETyApp e t => weakExprVarOccursFree wvf e + | WECoApp e co => weakExprVarOccursFree wvf e + | WENote n e => weakExprVarOccursFree wvf e + | WELam ev e => if eqd_dec (wvf:CoreVar) (ev:CoreVar) then false else weakExprVarOccursFree wvf e + | WETyLam tv e => weakExprVarOccursFree wvf e + | WECoLam cv e => weakExprVarOccursFree wvf e + | WECast e co => weakExprVarOccursFree wvf e + | WEBrak v wtv e t => weakExprVarOccursFree wvf e + | WEEsc v wtv e t => weakExprVarOccursFree wvf e + | WECSP v wtv e t => weakExprVarOccursFree wvf e + | WELet v ebind ebody => weakExprVarOccursFree wvf ebind + || if eqd_dec (wvf:CoreVar) (v:CoreVar) then false else weakExprVarOccursFree wvf ebody + | WECase vs es tb tc tys alts => + if weakExprVarOccursFree wvf es + then true + else (fix weakExprVarOccursFreeBranches (alts:Tree ??(_)) : bool := + match alts with + | T_Leaf None => false + | T_Leaf (Some (_,_,_,v',e')) => + if fold_left bor (map (fun v'':WeakExprVar => if eqd_dec (wvf:CoreVar) (v'':CoreVar) then true else false ) v') false + then false + else weakExprVarOccursFree wvf e' + | T_Branch b1 b2 => weakExprVarOccursFreeBranches b1 || + weakExprVarOccursFreeBranches b2 + end) alts + | WELetRec mlr e => false end. -(* wrap lambdas around an expression until it has no free expression variables *) -Definition makeClosedExpression : WeakExpr -> WeakExpr := - fun me => (fix closeExpression (me:WeakExpr)(cvl:list WeakExprVar) := - match cvl with - | nil => me - | cv::cvl' => WELam cv (closeExpression me cvl') - end) me (getWeakExprFreeVars me). - -(* messy first-order capture-avoiding substitution on CoreType's *) -Fixpoint replaceCoreVar (te:CoreType)(tv:CoreVar)(tsubst:CoreType) : CoreType := - match te with - | TyVarTy tv' => if eqd_dec tv tv' then tsubst else te - | AppTy t1 t2 => AppTy (replaceCoreVar t1 tv tsubst) (replaceCoreVar t2 tv tsubst) - | FunTy t1 t2 => FunTy (replaceCoreVar t1 tv tsubst) (replaceCoreVar t2 tv tsubst) - | ForAllTy tv' t => if eqd_dec tv tv' then te else ForAllTy tv' (replaceCoreVar t tv tsubst) - | PredTy (EqPred t1 t2) => PredTy (EqPred (replaceCoreVar t1 tv tsubst) (replaceCoreVar t2 tv tsubst)) - | PredTy (IParam ip ty) => PredTy (IParam ip (replaceCoreVar ty tv tsubst)) - | PredTy (ClassP _ c lt) => PredTy (ClassP c ((fix replaceCoreDistinctList (lt:list CoreType) := - match lt with - | nil => nil - | h::t => (replaceCoreVar h tv tsubst)::(replaceCoreDistinctList t) - end) lt)) - | TyConApp _ tc lt => TyConApp tc ((fix replaceCoreDistinctList (lt:list CoreType) := - match lt with - | nil => nil - | h::t => (replaceCoreVar h tv tsubst)::(replaceCoreDistinctList t) - end) lt) - end. - -(* calculate the CoreType of a WeakExpr *) -Fixpoint coreTypeOfWeakExpr (ce:WeakExpr) : ???CoreType := - match ce with - | WEVar (weakExprVar v t) => OK t - | WELit lit => OK (haskLiteralToCoreType lit) - | WEApp e1 e2 => coreTypeOfWeakExpr e1 >>= fun t' => - match t' with - | (TyConApp 2 tc (t1::t2::nil)) => - if (tyCon_eq tc ArrowTyCon) - then OK t2 - else Error ("found non-function type "+++(weakTypeToString t')+++" in EApp") - | _ => Error ("found non-function type "+++(weakTypeToString t')+++" in EApp") - end - | WETyApp e t => coreTypeOfWeakExpr e >>= fun te => - match te with - | ForAllTy v ct => OK (replaceCoreVar ct v t) - | _ => Error ("found non-forall type "+++(weakTypeToString te)+++" in ETyApp") - end - | WECoApp e co => coreTypeOfWeakExpr e >>= fun te => - match te with - | TyConApp 2 tc ((PredTy (EqPred t1 t2))::t3::nil) => - if (tyCon_eq tc ArrowTyCon) - then OK t3 - else Error ("found non-coercion type "+++(weakTypeToString te)+++" in ETyApp") - | _ => Error ("found non-coercion type "+++(weakTypeToString te)+++" in ETyApp") - end - | WELam (weakExprVar ev vt) e => coreTypeOfWeakExpr e >>= fun t' => OK (TyConApp ArrowTyCon (vt::t'::nil)) - | WETyLam tv e => coreTypeOfWeakExpr e >>= fun t' => match tv with weakTypeVar tvc _ => OK (ForAllTy tvc t') end - | WECoLam (weakCoerVar cv φ₁ φ₂) e => - coreTypeOfWeakExpr e >>= fun t' => OK (TyConApp ArrowTyCon ((PredTy (EqPred φ₁ φ₂))::t'::nil)) - | WELet ev ve e => coreTypeOfWeakExpr e - | WELetRec rb e => coreTypeOfWeakExpr e - | WENote n e => coreTypeOfWeakExpr e - | WECast e (weakCoercion t1 t2 _) => OK t2 - | WECase scrutinee tbranches n tc type_params alts => OK tbranches - - (* note that we willfully ignore the type stashed in WEBrak/WEEsc here *) - | WEBrak ec e _ => coreTypeOfWeakExpr e >>= fun t' => match ec with weakTypeVar ecc _ => - OK (TyConApp hetMetCodeTypeTyCon ((TyVarTy ecc)::t'::nil)) end - | WEEsc ec e _ => coreTypeOfWeakExpr e >>= fun t' => match ec with weakTypeVar ecc _ => - match t' with - | (TyConApp 2 tc ((TyVarTy ec')::t''::nil)) => - if (tyCon_eq tc hetMetCodeTypeTyCon) - then if eqd_dec ecc ec' then OK t'' - else Error "level mismatch in escapification" - else Error "ill-typed escapification" - | _ => Error "ill-typed escapification" - end end +(* some very simple-minded cleanups to produce "prettier" expressions *) +Fixpoint simplifyWeakExpr (me:WeakExpr) : WeakExpr := + match me with + | WEVar wv => WEVar wv + | WELit lit => WELit lit + | WEApp e1 e2 => WEApp (simplifyWeakExpr e1) (simplifyWeakExpr e2) + | WETyApp e t => WETyApp (simplifyWeakExpr e ) t + | WECoApp e co => CoreEApp (simplifyWeakExpr e ) co + | WENote n e => CoreENote n (simplifyWeakExpr e ) + | WELam ev e => CoreELam ev (simplifyWeakExpr e ) + | WETyLam tv e => CoreELam tv (simplifyWeakExpr e ) + | WECoLam cv e => CoreELam cv (simplifyWeakExpr e ) + | WECast e co => CoreECast (simplifyWeakExpr e ) co + | WEBrak v wtv e t => WEBrak v wtv (simplifyWeakExpr e ) t + | WEEsc v wtv e t => WEEsc v wtv (simplifyWeakExpr e ) t + | WECSP v wtv e t => WECSP v wtv (simplifyWeakExpr e ) t + | WELet v ebind ebody => WELet v (simplifyWeakExpr ebind) (simplifyWeakExpr ebody) + | WECase vs es tb tc tys alts => WECase vs es tb tc tys (* FIXME alts *) + (* un-letrec-ify multi branch letrecs *) + | WELetRec mlr e => WELetRec mlr (simplifyWeakExpr e ) end. - +*)