catala/compiler/dcalc/ast.mli
2022-03-17 12:30:14 +01:00

243 lines
7.5 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. *)
(** Abstract syntax tree of the default calculus intermediate representation *)
open Utils
module ScopeName : Uid.Id with type info = Uid.MarkedString.info
module StructName : Uid.Id with type info = Uid.MarkedString.info
module StructFieldName : Uid.Id with type info = Uid.MarkedString.info
module StructMap : Map.S with type key = StructName.t
module EnumName : Uid.Id with type info = Uid.MarkedString.info
module EnumConstructor : Uid.Id with type info = Uid.MarkedString.info
module EnumMap : Map.S with type key = EnumName.t
(** Abstract syntax tree for the default calculus *)
(** {1 Abstract syntax tree} *)
type typ_lit = TBool | TUnit | TInt | TRat | TMoney | TDate | TDuration
type typ =
| TLit of typ_lit
| TTuple of typ Pos.marked list * StructName.t option
| TEnum of typ Pos.marked list * EnumName.t
| TArrow of typ Pos.marked * typ Pos.marked
| TArray of typ Pos.marked
| TAny
type date = Runtime.date
type duration = Runtime.duration
type lit =
| LBool of bool
| LEmptyError
| LInt of Runtime.integer
| LRat of Runtime.decimal
| LMoney of Runtime.money
| LUnit
| LDate of date
| LDuration of duration
type op_kind =
| KInt
| KRat
| KMoney
| KDate
| KDuration (** All ops don't have a KDate and KDuration. *)
type ternop = Fold
type binop =
| And
| Or
| Xor
| Add of op_kind
| Sub of op_kind
| Mult of op_kind
| Div of op_kind
| Lt of op_kind
| Lte of op_kind
| Gt of op_kind
| Gte of op_kind
| Eq
| Neq
| Map
| Concat
| Filter
type log_entry =
| VarDef of typ
(** During code generation, we need to know the type of the variable being
logged for embedding *)
| BeginCall
| EndCall
| PosRecordIfTrueBool
type unop =
| Not
| Minus of op_kind
| Log of log_entry * Utils.Uid.MarkedString.info list
| Length
| IntToRat
| GetDay
| GetMonth
| GetYear
| RoundMoney
type operator = Ternop of ternop | Binop of binop | Unop of unop
(** The expressions use the {{:https://lepigre.fr/ocaml-bindlib/} Bindlib}
library, based on higher-order abstract syntax*)
type expr =
| EVar of expr Bindlib.var Pos.marked
| ETuple of expr Pos.marked list * StructName.t option
(** The [MarkedString.info] is the former struct field name*)
| ETupleAccess of
expr Pos.marked * int * StructName.t option * typ Pos.marked list
(** The [MarkedString.info] is the former struct field name *)
| EInj of expr Pos.marked * int * EnumName.t * typ Pos.marked list
(** The [MarkedString.info] is the former enum case name *)
| EMatch of expr Pos.marked * expr Pos.marked list * EnumName.t
(** The [MarkedString.info] is the former enum case name *)
| EArray of expr Pos.marked list
| ELit of lit
| EAbs of
((expr, expr Pos.marked) Bindlib.mbinder[@opaque]) Pos.marked
* typ Pos.marked list
| EApp of expr Pos.marked * expr Pos.marked list
| EAssert of expr Pos.marked
| EOp of operator
| EDefault of expr Pos.marked list * expr Pos.marked * expr Pos.marked
| EIfThenElse of expr Pos.marked * expr Pos.marked * expr Pos.marked
| ErrorOnEmpty of expr Pos.marked
type struct_ctx = (StructFieldName.t * typ Pos.marked) list StructMap.t
type enum_ctx = (EnumConstructor.t * typ Pos.marked) list EnumMap.t
type decl_ctx = { ctx_enums : enum_ctx; ctx_structs : struct_ctx }
type binder = (expr, expr Pos.marked) Bindlib.binder
(** This kind annotation signals that the let-binding respects a structural
invariant. These invariants concern the shape of the expression in the
let-binding, and are documented below. *)
type scope_let_kind =
| DestructuringInputStruct (** [let x = input.field]*)
| ScopeVarDefinition (** [let x = error_on_empty e]*)
| SubScopeVarDefinition
(** [let s.x = fun _ -> e] or [let s.x = error_on_empty e] for input-only
subscope variables. *)
| CallingSubScope (** [let result = s ({ x = s.x; y = s.x; ...}) ]*)
| DestructuringSubScopeResults (** [let s.x = result.x ]**)
| Assertion (** [let _ = assert e]*)
type scope_let = {
scope_let_var : expr Bindlib.var Pos.marked;
scope_let_kind : scope_let_kind;
scope_let_typ : typ Pos.marked;
scope_let_expr : expr Pos.marked Bindlib.box;
}
(** A scope let-binding has all the information necessary to make a proper
let-binding expression, plus an annotation for the kind of the let-binding
that comes from the compilation of a {!module: Scopelang.Ast} statement. *)
type scope_body = {
scope_body_lets : scope_let list;
scope_body_result : expr Pos.marked Bindlib.box;
scope_body_arg : expr Bindlib.var;
scope_body_input_struct : StructName.t;
scope_body_output_struct : StructName.t;
}
(** Instead of being a single expression, we give a little more ad-hoc structure
to the scope body by decomposing it in an ordered list of let-bindings, and
a result expression that uses the let-binded variables. *)
type program = {
decl_ctx : decl_ctx;
scopes : (ScopeName.t * expr Bindlib.var * scope_body) list;
}
(** {1 Helpers} *)
(** {2 Variables}*)
module Var : sig
type t = expr Bindlib.var
val make : string Pos.marked -> t
val compare : t -> t -> int
end
module VarMap : Map.S with type key = Var.t
val free_vars_set : expr Pos.marked -> unit VarMap.t
val free_vars_list : expr Pos.marked -> Var.t list
type vars = expr Bindlib.mvar
val make_var : Var.t Pos.marked -> expr Pos.marked Bindlib.box
val make_abs :
vars ->
expr Pos.marked Bindlib.box ->
Pos.t ->
typ Pos.marked list ->
Pos.t ->
expr Pos.marked Bindlib.box
val make_app :
expr Pos.marked Bindlib.box ->
expr Pos.marked Bindlib.box list ->
Pos.t ->
expr Pos.marked Bindlib.box
val make_let_in :
Var.t ->
typ Pos.marked ->
expr Pos.marked Bindlib.box ->
expr Pos.marked Bindlib.box ->
Pos.t ->
expr Pos.marked Bindlib.box
(**{2 Other}*)
val empty_thunked_term : expr Pos.marked
val is_value : expr Pos.marked -> bool
val equal_exprs : expr Pos.marked -> expr Pos.marked -> bool
(** Determines if two expressions are equal, omitting their position information *)
(** {1 AST manipulation helpers}*)
val build_whole_scope_expr :
decl_ctx -> scope_body -> Pos.t -> expr Pos.marked Bindlib.box
(** Usage: [build_whole_scope_expr ctx body scope_position] where
[scope_position] corresponds to the line of the scope declaration for
instance. *)
val build_whole_program_expr :
program -> ScopeName.t -> expr Pos.marked Bindlib.box
(** Usage: [build_whole_program_expr program main_scope] builds an expression
corresponding to the main program and returning the main scope as a
function. *)
val expr_size : expr Pos.marked -> int
(** Used by the optimizer to know when to stop *)
val variable_types : program -> typ Pos.marked VarMap.t
(** Traverses all the scopes and retrieves all the types for the variables that
may appear in scope or subscope variable definitions, giving them as a big
map. *)