Merge pull request #3 from joshuajaco/add-missing-rust-methods

Add missing rust methods

index.ts

@@ -6,6 +6,8 @@ type Methods<T, E> = {
   unwrapOrElse: (fn: (error: E) => T) => T;
   map: <U>(fn: (value: T) => U) => Result<U, E>;
   mapError: <F>(fn: (error: E) => F) => Result<T, F>;
+  mapOr: <U>(_default: U, fn: (value: T) => U) => U;
+  mapOrElse: <U>(defaultFn: (error: E) => U, fn: (value: T) => U) => U;
   and: <U>(result: Result<U, E>) => Result<U, E>;
   andThen: <U>(fn: (value: T) => Result<U, E>) => Result<U, E>;
   or: <F>(result: Result<T, F>) => Result<T, F>;
@@ -67,6 +69,14 @@ function createResult<T, E>(init: Attributes<T, E>): Result<T, E> {
       if (init.ok) return createResult(init);
       return createResult({ ok: false, error: fn(init.error) });
     },
+    mapOr(_default, fn) {
+      if (init.ok) return fn(init.value);
+      return _default;
+    },
+    mapOrElse(defaultFn, fn) {
+      if (init.ok) return fn(init.value);
+      return defaultFn(init.error);
+    },
     match(matcher) {
       if (init.ok) return matcher.ok(init.value);
       return matcher.error(init.error);

test.ts

@@ -134,6 +134,36 @@ assert(
   )
 );
 
+// mapOr
+
+assert.equal(
+  ok("foo").mapOr(42, (s) => s.length),
+  3
+);
+
+assert.equal(
+  error<string, string>("bar").mapOr(42, (s) => s.length),
+  42
+);
+
+// mapOrElse
+
+assert.equal(
+  ok("foo").mapOrElse(
+    (_e) => 42,
+    (s) => s.length
+  ),
+  3
+);
+
+assert.equal(
+  error<string, string>("bar").mapOrElse(
+    (e) => e.length * 3,
+    (s) => s.length
+  ),
+  9
+);
+
 // and
 
 assert(