feat: add Result#from and Result#fromAsync (#267)

src/lib/parsers/Result.ts

@@ -1,4 +1,5 @@
 import type * as Lexure from 'lexure';
+import { isFunction, Awaited } from '@sapphire/utilities';
 
 /**
  * A type used to express computations that can fail.
@@ -68,3 +69,29 @@ export function isOk<T, E>(x: Result<T, E>): x is Ok<T> {
 export function isErr<T, E>(x: Result<T, E>): x is Err<E> {
 	return !x.success;
 }
+
+/**
+ * Creates a {@link Result} out of a callback.
+ * @typeparam T The result's type.
+ * @typeparam E The error's type.
+ */
+export function from<T, E = Error>(cb: (...args: unknown[]) => T): Result<T, E> {
+	try {
+		return ok(cb());
+	} catch (error) {
+		return err(error as E);
+	}
+}
+
+/**
+ * Creates a {@link Result} out of a promise or async callback.
+ * @typeparam T The result's type.
+ * @typeparam E The error's type.
+ */
+export async function fromAsync<T, E = Error>(promiseOrCb: Awaited<T> | ((...args: unknown[]) => Awaited<T>)): Promise<Result<T, E>> {
+	try {
+		return ok(await (isFunction(promiseOrCb) ? promiseOrCb() : promiseOrCb));
+	} catch (error) {
+		return err(error as E);
+	}
+}