more utils

[chenglou]

let isTruthy x =>
switch (Js.Nullable.to_opt x) {
| None => false
| Some a => Js.to_bool a
};

let (|?) a b =>
switch a {
| None => b
| Some a => a
};

let isDefined x => Js.Nullable.to_opt x !== None;

/* TODO: @chenglou kill this */
let isSomeTrue a =>
switch a {
| None => false
| Some a => a
};

let nullUndefinedBooleanToOptionBool a =>
switch (Js.Nullable.to_opt a) {
| None => None
| Some a => Some (Js.to_bool a)
};

let optionBoolToNullUndefinedBoolean a =>
switch a {
| None => Js.Nullable.undefined
| Some a => Js.Nullable.return (Js.Boolean.to_js_boolean a)
};

let optionBoolToBoolean a =>
switch a {
| None => Js.false_
| Some a => Js.Boolean.to_js_boolean a
};

let listFilterMap f ls => {
let rec listFilterMap_ f ls accum =>
switch ls {
| [] => accum
| [item, ...rest] =>
switch (f item) {
| None => listFilterMap_ f rest accum
| Some item => listFilterMap_ f rest [item, ...accum]
}
};
listFilterMap_ f ls []
};

let arrayCompact l =>
l |>
Js.Array.filter (
fun item =>
switch item {
| None => false
| Some _ => true
}
) |>
Array.map (
fun
| None =>
raise (Invalid_argument "arrayCompact: sorry, something went wrong.")
| Some a => a
);