(* This file is part of the Catala compiler, a specification language for tax and social benefits computation rules. Copyright (C) 2020 Inria, contributor: Denis Merigoux Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. *) (** Translation from {!module: Desugared.Ast} to {!module: Scopelang.Ast} *) open Catala_utils open Shared_ast module D = Desugared.Ast (** {1 Expression translation}*) type target_scope_vars = | WholeVar of ScopeVar.t | States of (StateName.t * ScopeVar.t) list type ctx = { decl_ctx : decl_ctx; scope_var_mapping : target_scope_vars ScopeVar.Map.t; reentrant_vars : typ ScopeVar.Map.t; var_mapping : (D.expr, untyped Ast.expr Var.t) Var.Map.t; } let tag_with_log_entry (e : untyped Ast.expr boxed) (l : log_entry) (markings : Uid.MarkedString.info list) : untyped Ast.expr boxed = if Cli.globals.trace then Expr.eapp (Expr.eop (Log (l, markings)) [TAny, Expr.pos e] (Mark.get e)) [e] (Mark.get e) else e let rec translate_expr (ctx : ctx) (e : D.expr) : untyped Ast.expr boxed = let m = Mark.get e in match Mark.remove e with | EVar v -> Expr.evar (Var.Map.find v ctx.var_mapping) m | EAbs { binder; tys } -> let vars, body = Bindlib.unmbind binder in let new_vars = Array.map (fun var -> Var.make (Bindlib.name_of var)) vars in let ctx = List.fold_left2 (fun ctx var new_var -> { ctx with var_mapping = Var.Map.add var new_var ctx.var_mapping }) ctx (Array.to_list vars) (Array.to_list new_vars) in Expr.eabs (Expr.bind new_vars (translate_expr ctx body)) tys m | ELocation (SubScopeVar { scope; alias; var }) -> (* When referring to a subscope variable in an expression, we are referring to the output, hence we take the last state. *) let var = match ScopeVar.Map.find (Mark.remove var) ctx.scope_var_mapping with | WholeVar new_s_var -> Mark.copy var new_s_var | States states -> Mark.copy var (snd (List.hd (List.rev states))) in Expr.elocation (SubScopeVar { scope; alias; var }) m | ELocation (DesugaredScopeVar { name; state = None }) -> Expr.elocation (ScopelangScopeVar { name = (match ScopeVar.Map.find (Mark.remove name) ctx.scope_var_mapping with | WholeVar new_s_var -> Mark.copy name new_s_var | States _ -> failwith "should not happen"); }) m | ELocation (DesugaredScopeVar { name; state = Some state }) -> Expr.elocation (ScopelangScopeVar { name = (match ScopeVar.Map.find (Mark.remove name) ctx.scope_var_mapping with | WholeVar _ -> failwith "should not happen" | States states -> Mark.copy name (List.assoc state states)); }) m | ELocation (ToplevelVar v) -> Expr.elocation (ToplevelVar v) m | EDStructAccess _ -> assert false (* This shouldn't appear in desugared after disambiguation *) | EScopeCall { scope; args } -> Expr.escopecall ~scope ~args: (ScopeVar.Map.fold (fun v e args' -> let v' = match ScopeVar.Map.find v ctx.scope_var_mapping with | WholeVar v' -> v' | States ((_, v') :: _) -> (* When there are multiple states, the input is always the first one *) v' | States [] -> assert false in let e' = translate_expr ctx e in let m = Mark.get e in let e' = match ScopeVar.Map.find_opt v ctx.reentrant_vars with | Some (TArrow (targs, _), _) -> (* Functions are treated specially: the default only applies to their return type *) let arg = Var.make "arg" in let pos = Expr.mark_pos m in Expr.make_abs [| arg |] (Expr.edefault ~excepts:[] ~just:(Expr.elit (LBool true) m) ~cons: (Expr.epuredefault (Expr.make_app e' [Expr.evar arg m] pos) m) m) targs pos | Some _ -> Expr.epuredefault e' m | None -> e' in ScopeVar.Map.add v' e' args') args ScopeVar.Map.empty) m | EApp { f = EOp { op; tys }, m1; args } -> let args = List.map (translate_expr ctx) args in Operator.kind_dispatch op ~monomorphic:(fun op -> Expr.eapp (Expr.eop op tys m1) args m) ~polymorphic:(fun op -> Expr.eapp (Expr.eop op tys m1) args m) ~overloaded:(fun op -> match Operator.resolve_overload ctx.decl_ctx (Mark.add (Expr.pos e) op) tys with | op, `Straight -> Expr.eapp (Expr.eop op tys m1) args m | op, `Reversed -> Expr.eapp (Expr.eop op (List.rev tys) m1) (List.rev args) m) | EOp _ -> assert false (* Only allowed within [EApp] *) | ( EStruct _ | EStructAccess _ | ETuple _ | ETupleAccess _ | EInj _ | EMatch _ | ELit _ | EApp _ | EDefault _ | EPureDefault _ | EIfThenElse _ | EArray _ | EEmptyError | EErrorOnEmpty _ ) as e -> Expr.map ~f:(translate_expr ctx) (e, m) (** {1 Rule tree construction} *) (** Intermediate representation for the exception tree of rules for a particular scope definition. *) type rule_tree = | Leaf of D.rule list (** Rules defining a base case piecewise. List is non-empty. *) | Node of rule_tree list * D.rule list (** [Node (exceptions, base_case)] is a list of exceptions to a non-empty list of rules defining a base case piecewise. *) (** Transforms a flat list of rules into a tree, taking into account the priorities declared between rules *) let def_to_exception_graph (def_info : D.ScopeDef.t) (def : D.rule RuleName.Map.t) : Desugared.Dependency.ExceptionsDependencies.t = let exc_graph = Desugared.Dependency.build_exceptions_graph def def_info in Desugared.Dependency.check_for_exception_cycle def exc_graph; exc_graph let rule_to_exception_graph (scope : D.scope) = function | Desugared.Dependency.Vertex.Var (var, state) -> ( let scope_def = D.ScopeDef.Map.find (D.ScopeDef.Var (var, state)) scope.scope_defs in let var_def = scope_def.D.scope_def_rules in match Mark.remove scope_def.D.scope_def_io.io_input with | OnlyInput when not (RuleName.Map.is_empty var_def) -> (* If the variable is tagged as input, then it shall not be redefined. *) Message.raise_multispanned_error ((Some "Incriminated variable:", Mark.get (ScopeVar.get_info var)) :: List.map (fun rule -> ( Some "Incriminated variable definition:", Mark.get (RuleName.get_info rule) )) (RuleName.Map.keys var_def)) "It is impossible to give a definition to a scope variable tagged as \ input." | OnlyInput -> D.ScopeDef.Map.empty (* we do not provide any definition for an input-only variable *) | _ -> D.ScopeDef.Map.singleton (D.ScopeDef.Var (var, state)) (def_to_exception_graph (D.ScopeDef.Var (var, state)) var_def)) | Desugared.Dependency.Vertex.SubScope sub_scope_index -> (* Before calling the sub_scope, we need to include all the re-definitions of subscope parameters*) let sub_scope_vars_redefs_candidates = D.ScopeDef.Map.filter (fun def_key scope_def -> match def_key with | D.ScopeDef.Var _ -> false | D.ScopeDef.SubScopeVar (sub_scope_index', _, _) -> sub_scope_index = sub_scope_index' (* We exclude subscope variables that have 0 re-definitions and are not visible in the input of the subscope *) && not ((match Mark.remove scope_def.D.scope_def_io.io_input with | NoInput -> true | _ -> false) && RuleName.Map.is_empty scope_def.scope_def_rules)) scope.scope_defs in let sub_scope_vars_redefs = D.ScopeDef.Map.mapi (fun def_key scope_def -> let def = scope_def.D.scope_def_rules in let is_cond = scope_def.scope_def_is_condition in match def_key with | D.ScopeDef.Var _ -> assert false (* should not happen *) | D.ScopeDef.SubScopeVar (sscope, sub_scope_var, pos) -> (* This definition redefines a variable of the correct subscope. But we have to check that this redefinition is allowed with respect to the io parameters of that subscope variable. *) (match Mark.remove scope_def.D.scope_def_io.io_input with | NoInput -> Message.raise_multispanned_error (( Some "Incriminated subscope:", Mark.get (SubScopeName.get_info sscope) ) :: ( Some "Incriminated variable:", Mark.get (ScopeVar.get_info sub_scope_var) ) :: List.map (fun rule -> ( Some "Incriminated subscope variable definition:", Mark.get (RuleName.get_info rule) )) (RuleName.Map.keys def)) "It is impossible to give a definition to a subscope variable \ not tagged as input or context." | OnlyInput when RuleName.Map.is_empty def && not is_cond -> (* If the subscope variable is tagged as input, then it shall be defined. *) Message.raise_multispanned_error [ ( Some "Incriminated subscope:", Mark.get (SubScopeName.get_info sscope) ); Some "Incriminated variable:", pos; ] "This subscope variable is a mandatory input but no definition \ was provided." | _ -> ()); let exc_graph = def_to_exception_graph def_key def in let var_pos = D.ScopeDef.get_position def_key in exc_graph, sub_scope_var, var_pos) sub_scope_vars_redefs_candidates in List.fold_left (fun exc_graphs (new_exc_graph, subscope_var, var_pos) -> D.ScopeDef.Map.add (D.ScopeDef.SubScopeVar (sub_scope_index, subscope_var, var_pos)) new_exc_graph exc_graphs) D.ScopeDef.Map.empty (D.ScopeDef.Map.values sub_scope_vars_redefs) | Assertion _ -> D.ScopeDef.Map.empty (* no exceptions for assertions *) let scope_to_exception_graphs (scope : D.scope) : Desugared.Dependency.ExceptionsDependencies.t D.ScopeDef.Map.t = let scope_dependencies = Desugared.Dependency.build_scope_dependencies scope in Desugared.Dependency.check_for_cycle scope scope_dependencies; let scope_ordering = Desugared.Dependency.correct_computation_ordering scope_dependencies in List.fold_left (fun exceptions_graphs scope_def_key -> let new_exceptions_graphs = rule_to_exception_graph scope scope_def_key in D.ScopeDef.Map.disjoint_union new_exceptions_graphs exceptions_graphs) D.ScopeDef.Map.empty scope_ordering let build_exceptions_graph (pgrm : D.program) : Desugared.Dependency.ExceptionsDependencies.t D.ScopeDef.Map.t = ScopeName.Map.fold (fun _ scope exceptions_graph -> let new_exceptions_graphs = scope_to_exception_graphs scope in D.ScopeDef.Map.disjoint_union new_exceptions_graphs exceptions_graph) pgrm.program_root.module_scopes D.ScopeDef.Map.empty (** Transforms a flat list of rules into a tree, taking into account the priorities declared between rules *) let def_map_to_tree (def : D.rule RuleName.Map.t) (exc_graph : Desugared.Dependency.ExceptionsDependencies.t) : rule_tree list = (* we start by the base cases: they are the vertices which have no successors *) let base_cases = Desugared.Dependency.ExceptionsDependencies.fold_vertex (fun v base_cases -> if Desugared.Dependency.ExceptionsDependencies.out_degree exc_graph v = 0 then v :: base_cases else base_cases) exc_graph [] in let rec build_tree (base_cases : Desugared.Dependency.ExceptionVertex.t) : rule_tree = let exceptions = Desugared.Dependency.ExceptionsDependencies.pred exc_graph base_cases in let base_case_as_rule_list = List.map (fun r -> RuleName.Map.find r def) (RuleName.Map.keys base_cases.rules) in match exceptions with | [] -> Leaf base_case_as_rule_list | _ -> Node (List.map build_tree exceptions, base_case_as_rule_list) in List.map build_tree base_cases (** From the {!type: rule_tree}, builds an {!constructor: Dcalc.EDefault} expression in the scope language. The [~toplevel] parameter is used to know when to place the toplevel binding in the case of functions. *) let rec rule_tree_to_expr ~(toplevel : bool) ~(is_reentrant_var : bool) ~(subscope : bool) (ctx : ctx) (def_pos : Pos.t) (params : D.expr Var.t list option) (tree : rule_tree) : untyped Ast.expr boxed = let emark = Untyped { pos = def_pos } in let exceptions, base_rules = match tree with Leaf r -> [], r | Node (exceptions, r) -> exceptions, r in (* because each rule has its own variables parameters and we want to convert the whole rule tree into a function, we need to perform some alpha-renaming of all the expressions *) let substitute_parameter (e : D.expr boxed) (rule : D.rule) : D.expr boxed = match params, rule.D.rule_parameter with | Some new_params, Some (old_params_with_types, _) -> let old_params, _ = List.split old_params_with_types in let old_params = Array.of_list (List.map Mark.remove old_params) in let new_params = Array.of_list new_params in let binder = Bindlib.bind_mvar old_params (Mark.remove e) in Mark.add (Mark.get e) @@ Bindlib.box_apply2 (fun binder new_param -> Bindlib.msubst binder new_param) binder (new_params |> Array.map Bindlib.box_var |> Bindlib.box_array) | None, None -> e | _ -> assert false (* should not happen *) in let ctx = match params with | None -> ctx | Some new_params -> ListLabels.fold_left new_params ~init:ctx ~f:(fun ctx new_param -> match Var.Map.find_opt new_param ctx.var_mapping with | None -> let new_param_scope = Var.make (Bindlib.name_of new_param) in { ctx with var_mapping = Var.Map.add new_param new_param_scope ctx.var_mapping; } | Some _ -> (* We only create a mapping if none exists because [rule_tree_to_expr] is called recursively on the exceptions of the tree and we don't want to create a new Scopelang variable for the parameter at each tree level. *) ctx) in let base_just_list = List.map (fun rule -> substitute_parameter rule.D.rule_just rule) base_rules in let base_cons_list = List.map (fun rule -> substitute_parameter rule.D.rule_cons rule) base_rules in let translate_and_unbox_list (list : D.expr boxed list) : untyped Ast.expr boxed list = List.map (fun e -> (* There are two levels of boxing here, the outermost is introduced by the [translate_expr] function for which all of the bindings should have been closed by now, so we can safely unbox. *) translate_expr ctx (Expr.unbox e)) list in let default_containing_base_cases = Expr.edefault ~excepts: (List.fold_right2 (fun base_just base_cons acc -> match Expr.unbox base_just with | ELit (LBool false), _ -> acc | _ -> Expr.edefault ~excepts:[] (* Here we insert the logging command that records when a decision is taken for the value of a variable. *) ~just:(tag_with_log_entry base_just PosRecordIfTrueBool []) ~cons:(Expr.epuredefault base_cons emark) emark :: acc) (translate_and_unbox_list base_just_list) (translate_and_unbox_list base_cons_list) []) ~just:(Expr.elit (LBool false) emark) ~cons:(Expr.eemptyerror emark) emark in let exceptions = List.map (rule_tree_to_expr ~toplevel:false ~is_reentrant_var ~subscope ctx def_pos params) exceptions in let default = if exceptions = [] then default_containing_base_cases else Expr.edefault ~excepts:exceptions ~just:(Expr.elit (LBool true) emark) ~cons: (* if toplevel then Expr.eerroronempty default_containing_base_cases emark * else *) default_containing_base_cases emark in let default = if toplevel && not (subscope && is_reentrant_var) then Expr.eerroronempty default emark else default in match params, (List.hd base_rules).D.rule_parameter with | None, None -> default | Some new_params, Some (ls, _) -> let _, tys = List.split ls in if toplevel then (* When we're creating a function from multiple defaults, we must check that the result returned by the function is not empty, unless we're dealing with a context variable which is reentrant (either in the caller or callee). In this case the ErrorOnEmpty will be added later in the scopelang->dcalc translation. *) Expr.make_abs (new_params |> List.map (fun x -> Var.Map.find x ctx.var_mapping) |> Array.of_list) default tys def_pos else default | _ -> (* should not happen *) assert false (** {1 AST translation} *) (** Translates a definition inside a scope, the resulting expression should be an {!constructor: Dcalc.EDefault} *) let translate_def ~(is_cond : bool) ~(is_subscope_var : bool) (ctx : ctx) (def_info : D.ScopeDef.t) (def : D.rule RuleName.Map.t) (params : (Uid.MarkedString.info * typ) list Mark.pos option) (typ : typ) (io : D.io) (exc_graph : Desugared.Dependency.ExceptionsDependencies.t) : untyped Ast.expr boxed = (* Here, we have to transform this list of rules into a default tree. *) let top_list = def_map_to_tree def exc_graph in let is_input = match Mark.remove io.D.io_input with OnlyInput -> true | _ -> false in let is_reentrant = match Mark.remove io.D.io_input with Reentrant -> true | _ -> false in let top_value : D.rule option = if is_cond && ((not is_subscope_var) || (is_subscope_var && is_input)) then (* We add the bottom [false] value for conditions, only for the scope where the condition is declared. Except when the variable is an input, where we want the [false] to be added at each caller parent scope. *) Some (D.always_false_rule (D.ScopeDef.get_position def_info) params) else None in if RuleName.Map.cardinal def = 0 && is_subscope_var (* Here we have a special case for the empty definitions. Indeed, we could use the code for the regular case below that would create a convoluted default always returning empty error, and this would be correct. But it gets more complicated with functions. Indeed, if we create an empty definition for a subscope argument whose type is a function, we get something like [fun () -> (fun real_param -> < ... >)] that is passed as an argument to the subscope. The sub-scope de-thunks but the de-thunking does not return empty error, signalling there is not reentrant variable, because functions are values! So the subscope does not see that there is not reentrant variable and does not pick its internal definition instead. See [test/test_scope/subscope_function_arg_not_defined.catala_en] for a test case exercising that subtlety. To avoid this complication we special case here and put an empty error for all subscope variables that are not defined. It covers the subtlety with functions described above but also conditions with the false default value. *) && not (is_cond && is_input) (* However, this special case suffers from an exception: when a condition is defined as an OnlyInput to a subscope, since the [false] default value will not be provided by the calee scope, it has to be placed in the caller. *) then let m = Untyped { pos = D.ScopeDef.get_position def_info } in let empty_error = Expr.eemptyerror m in match params with | Some (ps, _) -> let labels, tys = List.split ps in Expr.make_abs (Array.of_list (List.map (fun lbl -> Var.make (Mark.remove lbl)) labels)) empty_error tys (Expr.mark_pos m) | _ -> empty_error else rule_tree_to_expr ~toplevel:true ~is_reentrant_var:is_reentrant ~subscope:is_subscope_var ctx (D.ScopeDef.get_position def_info) (Option.map (fun (ps, _) -> (List.map (fun (lbl, _) -> Var.make (Mark.remove lbl))) ps) params) (match top_list, top_value with | [], None -> (* In this case, there are no rules to define the expression and no default value so we put an empty rule. *) Leaf [D.empty_rule (Mark.get typ) params] | [], Some top_value -> (* In this case, there are no rules to define the expression but a default value so we put it. *) Leaf [top_value] | _, Some top_value -> (* When there are rules + a default value, we put the rules as exceptions to the default value *) Node (top_list, [top_value]) | [top_tree], None -> top_tree | _, None -> Node (top_list, [D.empty_rule (Mark.get typ) params])) let translate_rule ctx (scope : D.scope) (exc_graphs : Desugared.Dependency.ExceptionsDependencies.t D.ScopeDef.Map.t) = function | Desugared.Dependency.Vertex.Var (var, state) -> ( let scope_def = D.ScopeDef.Map.find (D.ScopeDef.Var (var, state)) scope.scope_defs in let var_def = scope_def.D.scope_def_rules in let var_params = scope_def.D.scope_def_parameters in let var_typ = scope_def.D.scope_def_typ in let is_cond = scope_def.D.scope_def_is_condition in match Mark.remove scope_def.D.scope_def_io.io_input with | OnlyInput when not (RuleName.Map.is_empty var_def) -> assert false (* error already raised *) | OnlyInput -> [] (* we do not provide any definition for an input-only variable *) | _ -> let scope_def_key = D.ScopeDef.Var (var, state) in let expr_def = translate_def ctx scope_def_key var_def var_params var_typ scope_def.D.scope_def_io (D.ScopeDef.Map.find scope_def_key exc_graphs) ~is_cond ~is_subscope_var:false in let scope_var = match ScopeVar.Map.find var ctx.scope_var_mapping, state with | WholeVar v, None -> v | States states, Some state -> List.assoc state states | _ -> failwith "should not happen" in [ Ast.Definition ( ( ScopelangScopeVar { name = scope_var, Mark.get (ScopeVar.get_info scope_var) }, Mark.get (ScopeVar.get_info scope_var) ), var_typ, scope_def.D.scope_def_io, Expr.unbox expr_def ); ]) | Desugared.Dependency.Vertex.SubScope sub_scope_index -> (* Before calling the sub_scope, we need to include all the re-definitions of subscope parameters*) let sub_scope = SubScopeName.Map.find sub_scope_index scope.scope_sub_scopes in let sub_scope_vars_redefs_candidates = D.ScopeDef.Map.filter (fun def_key scope_def -> match def_key with | D.ScopeDef.Var _ -> false | D.ScopeDef.SubScopeVar (sub_scope_index', _, _) -> sub_scope_index = sub_scope_index' (* We exclude subscope variables that have 0 re-definitions and are not visible in the input of the subscope *) && not ((match Mark.remove scope_def.D.scope_def_io.io_input with | NoInput -> true | _ -> false) && RuleName.Map.is_empty scope_def.scope_def_rules)) scope.scope_defs in let sub_scope_vars_redefs = D.ScopeDef.Map.mapi (fun def_key scope_def -> let def = scope_def.D.scope_def_rules in let def_typ = scope_def.scope_def_typ in let is_cond = scope_def.scope_def_is_condition in match def_key with | D.ScopeDef.Var _ -> assert false (* should not happen *) | D.ScopeDef.SubScopeVar (_, sub_scope_var, var_pos) -> (* This definition redefines a variable of the correct subscope. But we have to check that this redefinition is allowed with respect to the io parameters of that subscope variable. *) (match Mark.remove scope_def.D.scope_def_io.io_input with | NoInput -> assert false (* error already raised *) | OnlyInput when RuleName.Map.is_empty def && not is_cond -> assert false (* error already raised *) | _ -> ()); (* Now that all is good, we can proceed with translating this redefinition to a proper Scopelang term. *) let expr_def = translate_def ctx def_key def scope_def.D.scope_def_parameters def_typ scope_def.D.scope_def_io (D.ScopeDef.Map.find def_key exc_graphs) ~is_cond ~is_subscope_var:true in let def_typ = Scope.input_type def_typ scope_def.D.scope_def_io.D.io_input in let subscop_real_name = SubScopeName.Map.find sub_scope_index scope.scope_sub_scopes in Ast.Definition ( ( SubScopeVar { scope = subscop_real_name; alias = sub_scope_index, var_pos; var = (match ScopeVar.Map.find sub_scope_var ctx.scope_var_mapping with | WholeVar v -> v, var_pos | States states -> (* When defining a sub-scope variable, we always define its first state in the sub-scope. *) snd (List.hd states), var_pos); }, var_pos ), def_typ, scope_def.D.scope_def_io, Expr.unbox expr_def )) sub_scope_vars_redefs_candidates in let sub_scope_vars_redefs = D.ScopeDef.Map.values sub_scope_vars_redefs in sub_scope_vars_redefs @ [ Ast.Call ( sub_scope, sub_scope_index, Untyped { pos = Mark.get (SubScopeName.get_info sub_scope_index) } ); ] | Assertion a_name -> let assertion_expr = D.AssertionName.Map.find a_name scope.scope_assertions in (* we unbox here because assertions do not have free variables (at this point Bindlib variables are only for fuhnction parameters)*) let assertion_expr = translate_expr ctx (Expr.unbox assertion_expr) in [Ast.Assertion (Expr.unbox assertion_expr)] let translate_scope_interface ctx scope = let scope_sig = ScopeVar.Map.fold (fun var (states : D.var_or_states) acc -> let get_svar scope_def = let svar_in_ty = Scope.input_type scope_def.D.scope_def_typ scope_def.D.scope_def_io.io_input in { Ast.svar_in_ty; svar_out_ty = scope_def.D.scope_def_typ; svar_io = scope_def.scope_def_io; } in match states with | WholeVar -> let scope_def = D.ScopeDef.Map.find (D.ScopeDef.Var (var, None)) scope.D.scope_defs in ScopeVar.Map.add (match ScopeVar.Map.find var ctx.scope_var_mapping with | WholeVar v -> v | States _ -> failwith "should not happen") (get_svar scope_def) acc | States states -> (* What happens in the case of variables with multiple states is interesting. We need to create as many Var entries in the scope signature as there are states. *) List.fold_left (fun acc (state : StateName.t) -> let scope_def = D.ScopeDef.Map.find (D.ScopeDef.Var (var, Some state)) scope.D.scope_defs in ScopeVar.Map.add (match ScopeVar.Map.find var ctx.scope_var_mapping with | WholeVar _ -> failwith "should not happen" | States states' -> List.assoc state states') (get_svar scope_def) acc) acc states) scope.scope_vars ScopeVar.Map.empty in let pos = Mark.get (ScopeName.get_info scope.scope_uid) in Mark.add pos { Ast.scope_decl_name = scope.scope_uid; Ast.scope_decl_rules = []; Ast.scope_sig; Ast.scope_options = scope.scope_options; } let translate_scope (ctx : ctx) (exc_graphs : Desugared.Dependency.ExceptionsDependencies.t D.ScopeDef.Map.t) (scope : D.scope) : untyped Ast.scope_decl Mark.pos = let scope_dependencies = Desugared.Dependency.build_scope_dependencies scope in Desugared.Dependency.check_for_cycle scope scope_dependencies; let scope_ordering = Desugared.Dependency.correct_computation_ordering scope_dependencies in let scope_decl_rules = List.fold_left (fun scope_decl_rules scope_def_key -> let new_rules = translate_rule ctx scope exc_graphs scope_def_key in scope_decl_rules @ new_rules) [] scope_ordering in Mark.map (fun s -> { s with Ast.scope_decl_rules }) (translate_scope_interface ctx scope) (** {1 API} *) let translate_program (desugared : D.program) (exc_graphs : Desugared.Dependency.ExceptionsDependencies.t D.ScopeDef.Map.t) : untyped Ast.program = (* First we give mappings to all the locations between Desugared and This involves creating a new Scopelang scope variable for every state of a Desugared variable. *) let ctx = let ctx = { scope_var_mapping = ScopeVar.Map.empty; var_mapping = Var.Map.empty; reentrant_vars = ScopeVar.Map.empty; decl_ctx = desugared.program_ctx; } in let add_scope_mappings modul ctx = ScopeName.Map.fold (fun _ scdef ctx -> ScopeVar.Map.fold (fun scope_var (states : D.var_or_states) ctx -> let var_name, var_pos = ScopeVar.get_info scope_var in let new_var = match states with | D.WholeVar -> WholeVar (ScopeVar.fresh (var_name, var_pos)) | States states -> let var_prefix = var_name ^ "_" in let state_var state = ScopeVar.fresh (Mark.map (( ^ ) var_prefix) (StateName.get_info state)) in States (List.map (fun state -> state, state_var state) states) in let reentrant = let state = match states with | D.WholeVar -> None | States (s :: _) -> Some s | States [] -> assert false in match D.ScopeDef.Map.find_opt (Var (scope_var, state)) scdef.D.scope_defs with | Some { scope_def_io = { io_input = Runtime.Reentrant, _; _ }; scope_def_typ; _; } -> Some scope_def_typ | _ -> None in { ctx with scope_var_mapping = ScopeVar.Map.add scope_var new_var ctx.scope_var_mapping; reentrant_vars = Option.fold reentrant ~some:(fun ty -> ScopeVar.Map.add scope_var ty ctx.reentrant_vars) ~none:ctx.reentrant_vars; }) scdef.D.scope_vars ctx) modul.D.module_scopes ctx in (* Todo: since we rename all scope vars at this point, it would be better to have different types for Desugared.ScopeVar.t and Scopelang.ScopeVar.t *) ModuleName.Map.fold (fun _ m ctx -> add_scope_mappings m ctx) desugared.D.program_modules (add_scope_mappings desugared.D.program_root ctx) in let decl_ctx = let ctx_scopes = ScopeName.Map.map (fun out_str -> let out_struct_fields = ScopeVar.Map.fold (fun var fld out_map -> let var' = match ScopeVar.Map.find var ctx.scope_var_mapping with | WholeVar v -> v | States l -> snd (List.hd (List.rev l)) in ScopeVar.Map.add var' fld out_map) out_str.out_struct_fields ScopeVar.Map.empty in { out_str with out_struct_fields }) desugared.program_ctx.ctx_scopes in { desugared.program_ctx with ctx_scopes } in let ctx = { ctx with decl_ctx } in let program_modules = ModuleName.Map.map (fun m -> ScopeName.Map.map (translate_scope_interface ctx) m.D.module_scopes) desugared.D.program_modules in let program_topdefs = TopdefName.Map.mapi (fun id -> function | Some e, ty -> Expr.unbox (translate_expr ctx e), ty | None, (_, pos) -> Message.raise_spanned_error pos "No definition found for %a" TopdefName.format id) desugared.program_root.module_topdefs in let program_scopes = ScopeName.Map.map (translate_scope ctx exc_graphs) desugared.D.program_root.module_scopes in { Ast.program_module_name = Option.map ModuleName.fresh desugared.D.program_module_name; Ast.program_topdefs; Ast.program_scopes; Ast.program_ctx = ctx.decl_ctx; Ast.program_modules; Ast.program_lang = desugared.program_lang; }