function getValue(key) {
if (key) {
return 'value';
} else {
return undefined;
}
}
export { getValue };
@module("./play") @return(nullable) external getValue: string => option<string> = "getValue"
/* usage */
let v = getValue("")
switch v {
| Some(v') => Js.log(v')
| None => Js.log("undefined")
}
type doc
type elm
@val external document: doc = "document"
@send @return(nullable) external getElementById: (doc, string) => option<elm> = "getElementById"
/* usage */
let element = getElementById(document, "lesson")
switch element {
|Some(e) => Js.log(e)
|None => Js.log("Not Found")
}