pub const Tag = enum(u8) {
    /// `data` is ignored.
    true,
    /// `data` is ignored.
    false,
    /// `data` is ignored.
    null,
    /// `data` is ignored.
    pos_inf,
    /// `data` is ignored.
    neg_inf,
    /// `data` is ignored.
    nan,
    /// `data` is the `i32` value.
    int_literal_small,
    /// `data` is index into `extra` of:
    /// * `limb_count: u32`
    /// * `limbs_idx: u32`
    int_literal_pos,
    /// Identical to `int_literal_pos`, except the value is negative.
    int_literal_neg,
    /// `data` is the `f32` value.
    float_literal_small,
    /// `data` is index into `extra` of 4 elements which are a bitcast `f128`.
    float_literal,
    /// `data` is the `u32` value.
    char_literal,
    /// `data` is a `NullTerminatedString`.
    enum_literal,
    /// `data` is index into `extra` of:
    /// * `start: u32`
    /// * `len: u32`
    string_literal,
    /// Null-terminated string literal,
    /// `data` is a `NullTerminatedString`.
    string_literal_null,
    /// An empty struct/array literal, `.{}`.
    /// `data` is ignored.
    empty_literal,
    /// `data` is index into `extra` of:
    /// * `elem_count: u32`
    /// * `first_elem: Node.Index`
    /// The nodes `first_elem .. first_elem + elem_count` are the children.
    array_literal,
    /// `data` is index into `extra` of:
    /// * `elem_count: u32`
    /// * `first_elem: Node.Index`
    /// * `field_name: NullTerminatedString` for each `elem_count`
    /// The nodes `first_elem .. first_elem + elem_count` are the children.
    struct_literal,
}