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@alex35mil
Created April 8, 2020 12:19
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open Belt;
type t(+'a) = Js.Promise.t('a);
type error = Js.Promise.error;
type result('ok, 'error) = t(Result.t('ok, 'error));
[@bs.new]
external make:
(
[@bs.uncurry]
((~resolve: (. 'a) => unit, ~reject: (. exn) => unit) => unit)
) =>
t('a) =
"Promise";
[@bs.val] [@bs.scope "Promise"] external resolve: 'a => t('a) = "resolve";
[@bs.val] [@bs.scope "Promise"] external reject: exn => t('a) = "reject";
[@bs.val] [@bs.scope "Promise"]
external all: array(t('a)) => t(array('a)) = "all";
[@bs.val] [@bs.scope "Promise"]
external two: ((t('a0), t('a1))) => t(('a0, 'a1)) = "all";
[@bs.val] [@bs.scope "Promise"]
external three: ((t('a0), t('a1), t('a2))) => t(('a0, 'a1, 'a2)) = "all";
[@bs.val] [@bs.scope "Promise"]
external four:
((t('a0), t('a1), t('a2), t('a3))) => t(('a0, 'a1, 'a2, 'a3)) =
"all";
[@bs.val] [@bs.scope "Promise"]
external five:
((t('a0), t('a1), t('a2), t('a3), t('a4))) =>
t(('a0, 'a1, 'a2, 'a3, 'a4)) =
"all";
[@bs.val] [@bs.scope "Promise"]
external six:
((t('a0), t('a1), t('a2), t('a3), t('a4), t('a5))) =>
t(('a0, 'a1, 'a2, 'a3, 'a4, 'a5)) =
"all";
[@bs.val] [@bs.scope "Promise"]
external race: array(t('a)) => t('a) = "race";
[@bs.send]
external andThen: (t('a), [@bs.uncurry] ('a => t('b))) => t('b) = "then";
[@bs.send]
external catch: (t('a), [@bs.uncurry] (error => t('a))) => t('a) = "catch";
let map = (x: t('a), fn: 'a => 'b): t('b) =>
x->andThen(x => x->fn->resolve);
let tap = (x: t('a), fn: 'a => 'b): t('a) =>
x->andThen(x => {
x->fn;
x->resolve;
});
let result = (x: t('ok)): result('ok, 'error) =>
x
->andThen(x => Result.Ok(x)->resolve)
->catch(error => Result.Error(error)->resolve);
let mapResult = (x: t('ok), ~ok, ~error): result('ok, 'error) =>
x
->andThen(x => Result.Ok(x->ok)->resolve)
->catch(x => Result.Error(x->error)->resolve);
let mapOk = (x: result('ok, 'error), fn: 'ok => 'ok'): result('ok', 'error) =>
x->andThen(
fun
| Result.Ok(x) => Result.Ok(x->fn)->resolve
| Result.Error(x) => Result.Error(x)->resolve,
);
let mapError =
(x: result('ok, 'error), fn: 'error => 'error'): result('ok, 'error') =>
x->andThen(
fun
| Result.Ok(x) => Result.Ok(x)->resolve
| Result.Error(x) => Result.Error(x->fn)->resolve,
);
let wait = (x: result('ok, 'error), fn: Result.t('ok, 'error) => unit): unit =>
x->andThen(x => x->fn->resolve)->ignore;
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