catala/compiler/scopelang/from_desugared.ml
Louis Gesbert 75bf768264 Reformat
2024-04-04 10:56:56 +02:00

931 lines
36 KiB
OCaml

(* 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 <denis.merigoux@inria.fr>
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 Global.options.trace then
Expr.eappop
~op:(Log (l, markings))
~tys:[TAny, Expr.pos e]
~args:[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 (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] targs 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; tys; args } -> (
(* Detuplification of function arguments *)
let pos = Expr.pos f in
let f = translate_expr ctx f in
match args, tys with
| [arg], [_] -> Expr.eapp ~f ~tys m ~args:[translate_expr ctx arg]
| [(ETuple args, _)], _ ->
assert (List.length args = List.length tys);
Expr.eapp ~f ~tys m ~args:(List.map (translate_expr ctx) args)
| [((EVar _, _) as arg)], ts ->
let size = List.length ts in
let args =
let e = translate_expr ctx arg in
List.init size (fun index -> Expr.etupleaccess ~e ~size ~index m)
in
Expr.eapp ~f ~tys m ~args
| [arg], ts ->
let size = List.length ts in
let v = Var.make "args" in
let e = Expr.evar v (Mark.get arg) in
let args =
List.init size (fun index -> Expr.etupleaccess ~e ~size ~index m)
in
Expr.make_let_in v (TTuple ts, pos) (translate_expr ctx arg)
(Expr.eapp ~f ~tys m ~args)
pos
| args, tys ->
assert (List.length args = List.length tys);
Expr.eapp ~f ~tys m ~args:(List.map (translate_expr ctx) args))
| EAppOp { op; tys; args } ->
let args = List.map (translate_expr ctx) args in
Operator.kind_dispatch op
~monomorphic:(fun op -> Expr.eappop ~op ~tys ~args m)
~polymorphic:(fun op -> Expr.eappop ~op ~tys ~args m)
~overloaded:(fun op ->
match
Operator.resolve_overload ctx.decl_ctx (Mark.add (Expr.pos e) op) tys
with
| op, `Straight -> Expr.eappop ~op ~tys ~args m
| op, `Reversed ->
Expr.eappop ~op ~tys:(List.rev tys) ~args:(List.rev args) m)
| ( EStruct _ | EStructAccess _ | ETuple _ | ETupleAccess _ | EInj _
| EMatch _ | ELit _ | 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, None)
when ScopeVar.Map.mem var scope.scope_sub_scopes ->
(* Before calling the sub_scope, we need to include all the re-definitions
of subscope parameters*)
D.ScopeDef.Map.fold
(fun ((sscope, kind) as def_key) scope_def exc_graphs ->
match kind with
| D.ScopeDef.Var _ -> exc_graphs
| D.ScopeDef.SubScope _
when (not (ScopeVar.equal var (Mark.remove sscope)))
|| Mark.remove scope_def.D.scope_def_io.io_input = NoInput
&& RuleName.Map.is_empty scope_def.scope_def_rules ->
(* We exclude subscope variables that have 0 re-definitions and are
not visible in the input of the subscope *)
exc_graphs
| D.ScopeDef.SubScope { var_within_origin_scope; _ } ->
(* 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. *)
let def = scope_def.D.scope_def_rules in
let is_cond = scope_def.scope_def_is_condition in
let () =
match Mark.remove scope_def.D.scope_def_io.io_input with
| NoInput ->
Message.raise_multispanned_error
(( Some "Incriminated subscope:",
Mark.get (ScopeVar.get_info (Mark.remove sscope)) )
:: ( Some "Incriminated variable:",
Mark.get (ScopeVar.get_info var_within_origin_scope) )
:: List.map
(fun rule ->
( Some "Incriminated subscope variable definition:",
Mark.get (RuleName.get_info rule) ))
(RuleName.Map.keys def))
"Invalid assignment to a subscope variable that is 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 (ScopeVar.get_info (Mark.remove sscope)) );
Some "Incriminated variable:", Mark.get sscope;
]
"This subscope variable is a mandatory input but no definition \
was provided."
| _ -> ()
in
let new_exc_graph = def_to_exception_graph def_key def in
D.ScopeDef.Map.add def_key new_exc_graph exc_graphs)
scope.scope_defs D.ScopeDef.Map.empty
| Desugared.Dependency.Vertex.Var (var, state) -> (
let pos = Mark.get (ScopeVar.get_info var) in
let scope_def =
D.ScopeDef.Map.find ((var, pos), D.ScopeDef.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
((var, pos), D.ScopeDef.Var state)
(def_to_exception_graph ((var, pos), D.ScopeDef.Var state) var_def))
| 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 pos = Mark.get (ScopeVar.get_info var) in
(* TODO: this may point to the place where the variable was declared instead
of the binding in the definition being explored. Needs double-checking
and maybe adding more position information *)
let scope_def =
D.ScopeDef.Map.find ((var, pos), D.ScopeDef.Var state) scope.scope_defs
in
match ScopeVar.Map.find_opt var scope.scope_sub_scopes with
| None -> (
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 = (var, pos), D.ScopeDef.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
| _ -> assert false
in
[
Ast.ScopeVarDefinition
{
var = scope_var, pos;
typ = var_typ;
io = scope_def.D.scope_def_io;
e = Expr.unbox expr_def;
};
])
| Some subscope ->
(* Before calling the subscope, we need to include all the re-definitions
of subscope parameters *)
let subscope_params =
D.ScopeDef.Map.fold
(fun def_key scope_def acc ->
match def_key with
| _, D.ScopeDef.Var _ -> acc
| (v, _), D.ScopeDef.SubScope _
when (not (ScopeVar.equal var v))
|| Mark.remove scope_def.D.scope_def_io.io_input = NoInput
&& RuleName.Map.is_empty scope_def.scope_def_rules ->
acc
| v, D.ScopeDef.SubScope { var_within_origin_scope; _ } ->
let pos = Mark.get v in
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
assert (
(* an error should have been already raised *)
match scope_def.D.scope_def_io.io_input with
| NoInput, _ -> false
| OnlyInput, _ -> is_cond || not (RuleName.Map.is_empty def)
| _ -> true);
let var_within_origin_scope =
match
ScopeVar.Map.find var_within_origin_scope
ctx.scope_var_mapping
with
| WholeVar v -> v
| States ((_, v) :: _) -> v
| States [] -> assert false
in
let def_var =
Var.make
(String.concat "."
[
Mark.remove (ScopeVar.get_info (Mark.remove v));
Mark.remove (ScopeVar.get_info var_within_origin_scope);
])
in
let typ =
Scope.input_type def_typ scope_def.D.scope_def_io.D.io_input
in
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
ScopeVar.Map.add var_within_origin_scope
(def_var, pos, typ, expr_def)
acc)
scope.scope_defs ScopeVar.Map.empty
in
let subscope_param_map =
ScopeVar.Map.map (fun (_, _, _, expr) -> expr) subscope_params
in
let subscope_call_expr =
Expr.escopecall ~scope:subscope ~args:subscope_param_map
(Untyped { pos })
in
let subscope_expr = subscope_call_expr in
assert (RuleName.Map.is_empty scope_def.D.scope_def_rules);
(* The subscope will be defined by its inputs, it's not supposed to have
direct rules yet *)
let scope_info = ScopeName.Map.find subscope ctx.decl_ctx.ctx_scopes in
let subscope_var_dcalc =
match ScopeVar.Map.find var ctx.scope_var_mapping with
| WholeVar v -> v
| _ -> assert false
in
let subscope_def =
Ast.ScopeVarDefinition
{
var = subscope_var_dcalc, pos;
typ =
( TStruct scope_info.out_struct_name,
Mark.get (ScopeVar.get_info var) );
io = scope_def.D.scope_def_io;
e = Expr.unbox_closed subscope_expr;
}
in
[subscope_def])
| 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 function 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 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
let scope_sig =
(* Add the definitions of standard scope vars *)
ScopeVar.Map.fold
(fun var (states : D.var_or_states) acc ->
match states with
| WholeVar ->
let scope_def =
D.ScopeDef.Map.find
((var, Pos.no_pos), D.ScopeDef.Var None)
scope.D.scope_defs
in
ScopeVar.Map.add
(match ScopeVar.Map.find var ctx.scope_var_mapping with
| WholeVar v -> v
| States _ -> assert false)
(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
((var, Pos.no_pos), D.ScopeDef.Var (Some state))
scope.D.scope_defs
in
ScopeVar.Map.add
(match ScopeVar.Map.find var ctx.scope_var_mapping with
| WholeVar _ -> assert false
| States states' -> List.assoc state states')
(get_svar scope_def) acc)
acc states)
scope.scope_vars ScopeVar.Map.empty
in
let scope_sig =
(* Add the definition of vars corresponding to subscope calls, and their
parameters (subscope vars) *)
ScopeVar.Map.fold
(fun var _scope_name acc ->
let scope_def =
D.ScopeDef.Map.find
((var, Pos.no_pos), D.ScopeDef.Var None)
scope.D.scope_defs
in
ScopeVar.Map.add
(match ScopeVar.Map.find var ctx.scope_var_mapping with
| WholeVar v -> v
| States _ -> assert false)
(get_svar scope_def) acc)
scope.D.scope_sub_scopes scope_sig
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 ->
let ctx =
(* Add normal scope vars to the env *)
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
((scope_var, Pos.no_pos), 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
in
let ctx =
(* Add scope vars pointing to subscope executions to the env (their
definitions are introduced during the processing of the rules
above) *)
ScopeVar.Map.fold
(fun var _ ctx ->
let var_name, var_pos = ScopeVar.get_info var in
let scope_var_mapping =
let new_var = WholeVar (ScopeVar.fresh (var_name, var_pos)) in
ScopeVar.Map.add var new_var ctx.scope_var_mapping
in
{ ctx with scope_var_mapping })
scdef.D.scope_sub_scopes ctx
in
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;
}