use wasm_bindgen::{JsCast, JsValue};
use crate::{FromJs, ToJs, WrapJsCast};
macro_rules! def_option_like {
(
$name:ident {
None = $name_none:ident = $js_none_doc:literal $js_none:expr,
condition = |$from_js_ident:ident| $js_is_none:expr,
Some = $name_some:ident $(,)?
}
) => {
#[doc = concat!("Corresponding to `T | ", $js_none_doc, "`")]
#[doc = concat!("`", stringify!($name_none), "` => `", $js_none_doc, "`")]
#[doc = concat!("`", stringify!($name_some), "(value)` => `value`")]
#[derive(Copy, PartialEq, PartialOrd, Eq, Ord, Debug, Hash)]
pub enum $name<T> {
$name_none,
$name_some(T),
}
impl<T> $name<T> {
#[inline]
pub fn from_option(v: Option<T>) -> Self {
if let Some(v) = v {
Self::$name_some(v)
} else {
Self::$name_none
}
}
#[inline]
pub fn into_option(self) -> Option<T> {
match self {
Self::$name_none => None,
Self::$name_some(v) => Some(v),
}
}
#[inline]
pub fn as_ref(&self) -> $name<&T> {
match self {
Self::$name_none => $name::$name_none,
Self::$name_some(v) => $name::$name_some(v),
}
}
}
impl<T: Clone> Clone for $name<T> {
#[inline]
fn clone(&self) -> Self {
match self {
Self::$name_some(x) => Self::$name_some(x.clone()),
Self::$name_none => Self::$name_none,
}
}
#[inline]
fn clone_from(&mut self, source: &Self) {
match (self, source) {
(Self::$name_some(to), Self::$name_some(from)) => to.clone_from(from),
(to, from) => *to = from.clone(),
}
}
}
impl<T> Default for $name<T> {
#[doc = concat!("Returns [`", stringify!($name_none), "`][", stringify!($name), "::", stringify!($name_none), "]")]
#[inline]
fn default() -> $name<T> {
Self::$name_none
}
}
impl<T> From<Option<T>> for $name<T> {
#[inline]
fn from(v: Option<T>) -> Self {
Self::from_option(v)
}
}
impl<T> Into<Option<T>> for $name<T> {
#[inline]
fn into(self) -> Option<T> {
self.into_option()
}
}
impl<T: ToJs> ToJs for $name<T> {
fn to_js(&self) -> wasm_bindgen::JsValue {
match self {
Self::$name_none => $js_none,
Self::$name_some(v) => v.to_js(),
}
}
}
impl<T: FromJs> FromJs for $name<T> {
type Error = T::Error;
fn from_js($from_js_ident: wasm_bindgen::JsValue) -> Result<Self, Self::Error> {
if $js_is_none {
Ok(Self::$name_none)
} else {
T::from_js($from_js_ident).map(Self::$name_some)
}
}
}
impl<T: JsCast> $name<WrapJsCast<T>> {
pub fn wrap_js_cast(v: T) -> Self {
Self::$name_some(WrapJsCast(v))
}
}
};
}
def_option_like! {
Nullable {
None = Null = "null" JsValue::NULL,
condition = |v| v.is_null(),
Some = NonNull,
}
}
def_option_like! {
Maybe {
None = Undefined = "undefined" JsValue::UNDEFINED,
condition = |v| v.is_undefined(),
Some = Defined,
}
}