Add Result class

Author: valflrt

src/Result.ts

@@ -0,0 +1,39 @@
+export class Result<T> {
+  private _value!: T;
+
+  private _error?: any = null;
+
+  constructor(
+    executor: (
+      resolve: (value: T) => void,
+      reject: (error?: any) => void
+    ) => unknown
+  ) {
+    try {
+      executor(
+        (v) => (this._value = v),
+        (e: any) => (this._error = e)
+      );
+    } catch (e) {
+      this._error = e;
+    }
+  }
+
+  /**
+   * Returns the Result value or executes the callback if an error was encountered
+   */
+  public tryToUnpack(catchError: (error: any) => unknown): T | null {
+    if (this._error) {
+      catchError(this._error);
+      return null;
+    } else return this._value ?? null;
+  }
+
+  /**
+   * Returns the Result value (throws if an error was encountered)
+   */
+  public unpack() {
+    if (this._error) throw this._error;
+    return this._value;
+  }
+}