catala/compiler/scalc/ast.ml
Louis Gesbert a415355a39 Rework the AST Gadt to allow merging of different ASTs
The phantom polymorphic variant qualifying AST nodes is reversed:
- previously, we were explicitely restricting each AST node to the passes where it belonged using a closed type (e.g. `[< dcalc | lcalc]`)
- now, each node instead declares the "feature" it provides using an open type (e.g. `[> 'Exceptions ]`)
- then the AST for a specific pass limits the features it allows with a closed type

The result is that you can mix and match all features if you wish,
even if the result is not a valid AST for any given pass. More
interestingly, it's now easier to write a function that works on
different ASTs at once (it's the inferred default if you don't write a
type restriction).

The opportunity was also taken to simplify the encoding of the
operators, which don't need a second type parameter anymore.
2023-03-30 15:30:08 +02:00

78 lines
2.6 KiB
OCaml

(* This file is part of the Catala compiler, a specification language for tax
and social benefits computation rules. Copyright (C) 2021 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. *)
open Catala_utils
open Shared_ast
module D = Dcalc.Ast
module L = Lcalc.Ast
module FuncName = Uid.Gen ()
module VarName = Uid.Gen ()
let dead_value = VarName.fresh ("dead_value", Pos.no_pos)
let handle_default = FuncName.fresh ("handle_default", Pos.no_pos)
let handle_default_opt = FuncName.fresh ("handle_default_opt", Pos.no_pos)
type operator = [ `Monomorphic | `Polymorphic | `Resolved ] Shared_ast.operator
type expr = naked_expr Marked.pos
and naked_expr =
| EVar : VarName.t -> naked_expr
| EFunc : FuncName.t -> naked_expr
| EStruct : expr list * StructName.t -> naked_expr
| EStructFieldAccess : expr * StructField.t * StructName.t -> naked_expr
| EInj : expr * EnumConstructor.t * EnumName.t -> naked_expr
| EArray : expr list -> naked_expr
| ELit : L.lit -> naked_expr
| EApp : expr * expr list -> naked_expr
| EOp : operator -> naked_expr
type stmt =
| SInnerFuncDef of VarName.t Marked.pos * func
| SLocalDecl of VarName.t Marked.pos * typ
| SLocalDef of VarName.t Marked.pos * expr
| STryExcept of block * except * block
| SRaise of except
| SIfThenElse of expr * block * block
| SSwitch of
expr
* EnumName.t
* (block (* Statements corresponding to arm closure body*)
* (* Variable instantiated with enum payload *) VarName.t)
list (** Each block corresponds to one case of the enum *)
| SReturn of naked_expr
| SAssert of naked_expr
and block = stmt Marked.pos list
and func = {
func_params : (VarName.t Marked.pos * typ) list;
func_body : block;
}
type scope_body = {
scope_body_name : ScopeName.t;
scope_body_var : FuncName.t;
scope_body_func : func;
}
type code_item =
| SVar of { var : VarName.t; expr : expr }
| SFunc of { var : FuncName.t; func : func }
| SScope of scope_body
type program = { decl_ctx : decl_ctx; code_items : code_item list }