Macro ocaml_interop::ocaml_unpack_record

macro_rules! ocaml_unpack_record {
    ($var : ident => $cons : ident
 { $($field : ident : $ocaml_typ : ty), + $(,) ? }) => { ... };
    ($var : ident => $cons : ident($($field : ident : $ocaml_typ : ty), + $(,) ?)) => { ... };
}

Unpacks an OCaml record into a Rust record.

This macro works on OCaml<'gc, T> values.

It is important that the order of the fields remains the same as in the OCaml type declaration.

Examples

struct MyStruct {
    int_field: i64,
    string_field: String,
}

// Assuming an OCaml record declaration like:
//
//      type my_struct = {
//          int_field: int;
//          string_field: string;
//      }
//
// NOTE: What is important is the order of the fields, not their names.

let ocaml_struct_root = make_mystruct(cr, &OCaml::unit());
let ocaml_struct = cr.get(&ocaml_struct_root);
let my_struct = ocaml_unpack_record! {
    //  value    => RustConstructor { field: OCamlType, ... }
    ocaml_struct => MyStruct {
        int_field: OCamlInt,
        string_field: String,
    }
};
// ...