Method extend_pyclass

crates/vm/src/types/structseq.rs:302–393

(ctx: &Context, class: &'static Py<PyType>)

    #[extend_class]
    fn extend_pyclass(ctx: &Context, class: &'static Py<PyType>) {
        // Getters for named visible fields (indices 0 to REQUIRED_FIELD_NAMES.len() - 1)
        for (i, &name) in Self::Data::REQUIRED_FIELD_NAMES.iter().enumerate() {
            // cast i to a u8 so there's less to store in the getter closure.
            // Hopefully there's not struct sequences with >=256 elements :P
            let i = i as u8;
            class.set_attr(
                ctx.intern_str(name),
                ctx.new_readonly_getset(name, class, move |zelf: &PyTuple| {
                    zelf[i as usize].to_owned()
                })
                .into(),
            );
        }

        // Getters for hidden/skipped fields (indices after visible fields)
        let visible_count = Self::Data::REQUIRED_FIELD_NAMES.len() + Self::Data::UNNAMED_FIELDS_LEN;
        for (i, &name) in Self::Data::OPTIONAL_FIELD_NAMES.iter().enumerate() {
            let idx = (visible_count + i) as u8;
            class.set_attr(
                ctx.intern_str(name),
                ctx.new_readonly_getset(name, class, move |zelf: &PyTuple| {
                    zelf[idx as usize].to_owned()
                })
                .into(),
            );
        }

        class.set_attr(
            identifier!(ctx, __match_args__),
            ctx.new_tuple(
                Self::Data::REQUIRED_FIELD_NAMES
                    .iter()
                    .map(|&name| ctx.new_str(name).into())
                    .collect::<Vec<_>>(),
            )
            .into(),
        );

        // special fields:
        // n_sequence_fields = visible fields (named + unnamed)
        // n_fields = all fields (visible + hidden/skipped)
        // n_unnamed_fields
        let n_unnamed_fields = Self::Data::UNNAMED_FIELDS_LEN;
        let n_sequence_fields = Self::Data::REQUIRED_FIELD_NAMES.len() + n_unnamed_fields;
        let n_fields = n_sequence_fields + Self::Data::OPTIONAL_FIELD_NAMES.len();
        class.set_attr(
            identifier!(ctx, n_sequence_fields),
            ctx.new_int(n_sequence_fields).into(),
        );
        class.set_attr(identifier!(ctx, n_fields), ctx.new_int(n_fields).into());
        class.set_attr(
            identifier!(ctx, n_unnamed_fields),
            ctx.new_int(n_unnamed_fields).into(),
        );

        // Override as_sequence and as_mapping slots to use visible length
        class