lustrec / src / init_calculus.ml @ a2d97a3e
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(********************************************************************) 

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(* *) 
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(* The LustreC compiler toolset / The LustreC Development Team *) 
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(* Copyright 2012   ONERA  CNRS  INPT *) 
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(* *) 
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(* LustreC is free software, distributed WITHOUT ANY WARRANTY *) 
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(* under the terms of the GNU Lesser General Public License *) 
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(* version 2.1. *) 
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(* *) 
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(********************************************************************) 
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(** Main typing module. Classic inference algorithm with destructive 
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unification. *) 
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(* Though it shares similarities with the clock calculus module, no code 
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is shared. Simple environments, very limited identifier scoping, no 
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identifier redefinition allowed. *) 
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open Utils 
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(* Yes, opening both modules is dirty as some type names will be 
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overwritten, yet this makes notations far lighter.*) 
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open Corelang 
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open Init 
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open Format 
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(** [occurs tvar ty] returns true if the type variable [tvar] occurs in 
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type [ty]. False otherwise. *) 
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let rec occurs tvar ty = 
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let ty = repr ty in 
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match ty.tdesc with 
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 Ivar > ty=tvar 
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 Iarrow (t1, t2) > 
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(occurs tvar t1)  (occurs tvar t2) 
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 Ituple tl > 
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List.exists (occurs tvar) tl 
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 Ilink t > occurs tvar t 
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 Isucc t > occurs tvar t 
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 Iunivar > false 
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(** Promote monomorphic type variables to polymorphic type variables. *) 
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(* Generalize by sideeffects *) 
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let rec generalize ty = 
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match ty.tdesc with 
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 Ivar > 
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(* No scopes, always generalize *) 
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ty.idesc < Iunivar 
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 Iarrow (t1,t2) > 
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generalize t1; generalize t2 
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 Ituple tlist > 
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List.iter generalize tlist 
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 Ilink t > 
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generalize t 
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 Isucc t > 
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generalize t 
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 Tunivar > () 
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(** Downgrade polymorphic type variables to monomorphic type variables *) 
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let rec instanciate inst_vars ty = 
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let ty = repr ty in 
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match ty.idesc with 
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 Ivar > ty 
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 Iarrow (t1,t2) > 
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{ty with idesc = 
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Iarrow ((instanciate inst_vars t1), (instanciate inst_vars t2))} 
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 Ituple tlist > 
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{ty with idesc = Ituple (List.map (instanciate inst_vars) tlist)} 
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 Isucc t > 
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(* should not happen *) 
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{ty with idesc = Isucc (instanciate inst_vars t)} 
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 Ilink t > 
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(* should not happen *) 
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{ty with idesc = Ilink (instanciate inst_vars t)} 
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 Iunivar > 
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try 
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List.assoc ty.iid !inst_vars 
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with Not_found > 
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let var = new_var () in 
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inst_vars := (ty.iid, var)::!inst_vars; 
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var 
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(** [unify env t1 t2] unifies types [t1] and [t2]. Raises [Unify 
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(t1,t2)] if the types are not unifiable.*) 
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(* Standard destructive unification *) 
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(* may loop for omega types *) 
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let rec unify t1 t2 = 
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let t1 = repr t1 in 
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let t2 = repr t2 in 
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if t1=t2 then 
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() 
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else 
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(* No type abbreviations resolution for now *) 
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match t1.idesc,t2.idesc with 
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(* This case is not mandory but will keep "older" types *) 
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 Ivar, Ivar > 
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if t1.iid < t2.iid then 
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t2.idesc < Ilink t1 
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else 
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t1.idesc < Ilink t2 
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 (Ivar, _) when (not (occurs t1 t2)) > 
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t1.idesc < Ilink t2 
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 (_,Ivar) when (not (occurs t2 t1)) > 
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t2.idesc < Ilink t1 
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 Isucc t1, Isucc t1' > unify t1 t1' 
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 Iarrow (t1,t2), Iarrow (t1',t2') > 
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unify t1 t1'; unify t2 t2' 
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 Ituple tlist1, Ituple tlist2 > 
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if (List.length tlist1) <> (List.length tlist2) then 
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raise (Unify (t1, t2)) 
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else 
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List.iter2 unify tlist1 tlist2 
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 Iunivar,_  _, Iunivar > 
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() 
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 _,_ > raise (Unify (t1, t2)) 
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let init_of_const c = 
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Init_predef.init_zero 
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let rec init_expect env in_main expr ty = 
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let texpr = init_expr env in_main expr in 
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try 
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unify texpr ty 
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with Unify (t1,t2) > 
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raise (Error (expr.expr_loc, Init_clash (t1,t2))) 
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and init_ident env in_main id loc = 
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init_expr env in_main (expr_of_ident id loc) 
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(** [type_expr env in_main expr] types expression [expr] in environment 
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[env]. *) 
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and init_expr env in_main expr = 
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match expr.expr_desc with 
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 Expr_const c > 
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let ty = init_of_const c in 
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expr.expr_init < ty; 
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ty 
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 Expr_ident v > 
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let tyv = 
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try 
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Env.lookup_value env v 
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with Not_found > 
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raise (Error (expr.expr_loc, Unbound_value v)) 
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in 
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let ty = instanciate (ref []) tyv in 
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expr.expr_init < ty; 
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ty 
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 Expr_tuple elist > 
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let ty = new_ty (Ttuple (List.map (type_expr env in_main) elist)) in 
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expr.expr_init < ty; 
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ty 
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 Expr_appl (id, args, r) > 
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(match r with 
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 None > () 
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 Some x > let expr_x = expr_of_ident x expr.expr_loc in 
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init_expect env in_main expr_x Init_predef.init_zero); 
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let tfun = type_ident env in_main id expr.expr_loc in 
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let tins,touts= split_arrow tfun in 
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type_expect env in_main args tins; 
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expr.expr_type < touts; 
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touts 
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 Expr_arrow (e1,e2) > 
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let ty = type_expr env in_main e1 in 
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type_expect env in_main e2 ty; 
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expr.expr_type < ty; 
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ty 
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 Expr_fby (init,e) > 
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let ty = type_of_const init in 
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type_expect env in_main e ty; 
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expr.expr_type < ty; 
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ty 
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 Expr_concat (hd,e) > 
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let ty = type_of_const hd in 
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type_expect env in_main e ty; 
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expr.expr_type < ty; 
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ty 
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 Expr_tail e > 
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let ty = type_expr env in_main e in 
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expr.expr_type < ty; 
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ty 
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 Expr_pre e > 
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let ty = type_expr env in_main e in 
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expr.expr_type < ty; 
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ty 
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 Expr_when (e1,c)  Expr_whennot (e1,c) > 
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let expr_c = expr_of_ident c expr.expr_loc in 
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type_expect env in_main expr_c Type_predef.type_bool; 
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let tlarg = type_expr env in_main e1 in 
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expr.expr_type < tlarg; 
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tlarg 
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 Expr_merge (c,e2,e3) > 
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let expr_c = expr_of_ident c expr.expr_loc in 
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type_expect env in_main expr_c Type_predef.type_bool; 
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let te2 = type_expr env in_main e2 in 
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type_expect env in_main e3 te2; 
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expr.expr_type < te2; 
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te2 
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 Expr_uclock (e,k)  Expr_dclock (e,k) > 
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let ty = type_expr env in_main e in 
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expr.expr_type < ty; 
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ty 
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 Expr_phclock (e,q) > 
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let ty = type_expr env in_main e in 
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expr.expr_type < ty; 
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ty 
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(** [type_eq env eq] types equation [eq] in environment [env] *) 
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let type_eq env in_main undefined_vars eq = 
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(* Check multiple variable definitions *) 
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let define_var id uvars = 
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try 
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ignore(IMap.find id uvars); 
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IMap.remove id uvars 
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with Not_found > 
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raise (Error (eq.eq_loc, Already_defined id)) 
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in 
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let undefined_vars = 
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List.fold_left (fun uvars v > define_var v uvars) undefined_vars eq.eq_lhs in 
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(* Type lhs *) 
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let get_value_type id = 
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try 
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Env.lookup_value env id 
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with Not_found > 
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raise (Error (eq.eq_loc, Unbound_value id)) 
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in 
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let tyl_lhs = List.map get_value_type eq.eq_lhs in 
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let ty_lhs = type_of_type_list tyl_lhs in 
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(* Type rhs *) 
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type_expect env in_main eq.eq_rhs ty_lhs; 
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undefined_vars 
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(* [type_coretype cty] types the type declaration [cty] *) 
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let type_coretype cty = 
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match cty with 
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 Tydec_any > new_var () 
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 Tydec_int > Type_predef.type_int 
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 Tydec_real > Type_predef.type_real 
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 Tydec_float > Type_predef.type_real 
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 Tydec_bool > Type_predef.type_bool 
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 Tydec_clock > Type_predef.type_clock 
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(* [type_coreclock env ck id loc] types the type clock declaration [ck] 
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in environment [env] *) 
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let type_coreclock env ck id loc = 
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match ck.ck_dec_desc with 
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 Ckdec_any  Ckdec_pclock (_,_) > () 
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 Ckdec_bool cl > 
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let dummy_id_expr = expr_of_ident id loc in 
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let when_expr = 
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List.fold_left 
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(fun expr c > 
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match c with 
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 Wtrue id > 
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{expr_tag = new_tag (); 
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expr_desc=Expr_when (expr,id); 
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expr_type = new_var (); 
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expr_clock = Clocks.new_var true; 
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expr_loc=loc} 
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 Wfalse id > 
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{expr_tag = new_tag (); 
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expr_desc=Expr_whennot (expr,id); 
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expr_type = new_var (); 
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expr_clock = Clocks.new_var true; 
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expr_loc=loc}) 
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dummy_id_expr cl 
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in 
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ignore (type_expr env false when_expr) 
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let type_var_decl env vdecl = 
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if (Env.exists_value env vdecl.var_id) then 
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raise (Error (vdecl.var_loc,Already_bound vdecl.var_id)) 
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else 
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let ty = type_coretype vdecl.var_dec_type.ty_dec_desc in 
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let new_env = Env.add_value env vdecl.var_id ty in 
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type_coreclock new_env vdecl.var_dec_clock vdecl.var_id vdecl.var_loc; 
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vdecl.var_type < ty; 
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new_env 
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let type_var_decl_list env l = 
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List.fold_left type_var_decl env l 
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let type_of_vlist vars = 
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let tyl = List.map (fun v > v.var_type) vars in 
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type_of_type_list tyl 
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(** [type_node env nd loc] types node [nd] in environment env. The 
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location is used for error reports. *) 
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let type_node env nd loc = 
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let is_main = nd.node_id = !Options.main_node in 
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let delta_env = type_var_decl_list IMap.empty nd.node_inputs in 
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let delta_env = type_var_decl_list delta_env nd.node_outputs in 
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let delta_env = type_var_decl_list delta_env nd.node_locals in 
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let new_env = Env.overwrite env delta_env in 
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let undefined_vars_init = 
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List.fold_left 
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(fun uvs v > IMap.add v.var_id () uvs) 
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IMap.empty (nd.node_outputs@nd.node_locals) in 
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let undefined_vars = 
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List.fold_left (type_eq new_env is_main) undefined_vars_init nd.node_eqs 
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in 
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(* check that table is empty *) 
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if (not (IMap.is_empty undefined_vars)) then 
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raise (Error (loc,Undefined_var undefined_vars)); 
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let ty_ins = type_of_vlist nd.node_inputs in 
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let ty_outs = type_of_vlist nd.node_outputs in 
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let ty_node = new_ty (Tarrow (ty_ins,ty_outs)) in 
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generalize ty_node; 
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(* TODO ? Check that no node in the hierarchy remains polymorphic ? *) 
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nd.node_type < ty_node; 
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Env.add_value env nd.node_id ty_node 
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let type_imported_node env nd loc = 
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let new_env = type_var_decl_list env nd.nodei_inputs in 
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ignore(type_var_decl_list new_env nd.nodei_outputs); 
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let ty_ins = type_of_vlist nd.nodei_inputs in 
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let ty_outs = type_of_vlist nd.nodei_outputs in 
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let ty_node = new_ty (Tarrow (ty_ins,ty_outs)) in 
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generalize ty_node; 
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if (is_polymorphic ty_node) then 
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raise (Error (loc, Poly_imported_node nd.nodei_id)); 
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let new_env = Env.add_value env nd.nodei_id ty_node in 
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nd.nodei_type < ty_node; 
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new_env 
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let type_top_decl env decl = 
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match decl.top_decl_desc with 
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 Node nd > 
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type_node env nd decl.top_decl_loc 
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 ImportedNode nd > 
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type_imported_node env nd decl.top_decl_loc 
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 SensorDecl _  ActuatorDecl _  Consts _ > env 
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let type_top_consts env decl = 
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match decl.top_decl_desc with 
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 Consts clist > 
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List.fold_left (fun env (id, c) > 
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let ty = type_of_const c in 
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Env.add_value env id ty 
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) env clist 
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 Node _  ImportedNode _  SensorDecl _  ActuatorDecl _ > env 
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let type_prog env decls = 
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let new_env = List.fold_left type_top_consts env decls in 
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ignore(List.fold_left type_top_decl new_env decls) 
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(* Local Variables: *) 
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(* compilecommand:"make C .." *) 
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(* End: *) 