René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Design Meeting Notes, 8/25/2017","articleBody":"# Add `promised` type (continued)\r\n\r\nhttps://github.com/Microsoft/TypeScript/pull/17077\r\n\r\n* Never had a name for this.\r\n    * `await`?\r\n    * `awaited`?\r\n    * Positive sentiment for both.\r\n* How bad is the world without this?\r\n    * Well stricter generic checks broke a lot of checking.\r\n    * But are things fixed now? We've gotten this far without it.\r\n* Would love to see specifically why we need to do this.\r\n    * PR has some examples.\r\n* At the end of the last meeting we had two open issues:\r\n    * Naming\r\n    * Highed order relationships.\r\n* What if we just worked on some of the inference issues that `Promise`/`PromiseLike`s experience relating to union type inference?\r\n    * [Follow up with @rbuckton]\r\n\r\n# String enums and indexing\r\n\r\n* Now that string-enums are a thing, people want to use them everywhere, like in\r\n    * interface/literal types.\r\n    * computed properties\r\n* Would need to generalize declarations constructed with literal types:\r\n\r\n  ```ts\r\n  const b = \"b\";\r\n  const x = {\r\n      [b]: 100,\r\n  }\r\n\r\n  // equivalent to\r\n\r\n  const y = {\r\n      b: 100,\r\n  }\r\n  ```\r\n* What would we do in the case of\r\n\r\n  ```ts\r\n  declare const x: \"a\" | \"b\";\r\n  const a = {\r\n      [x]: 100,\r\n  }\r\n  ```\r\n    * Is that\r\n\r\n      ```ts\r\n      //    { a: number } | { b: number }\r\n      // or\r\n      //    { a?: number, b?: number }\r\n      // or\r\n      //    { [x: string]: number }\r\n      ```\r\n* Leaning towards last option for practicality.\r\n* What about cases where you want to quickly manufacture distinct cases?\r\n\r\n  ```ts\r\n  function createThing\u003cK extends \"a\" | \"b\", payload: T\u003e(kind: K, payload: T) {\r\n      return {\r\n          kind,\r\n          payload: {\r\n              [kind]: T,\r\n          }\r\n      };\r\n  }\r\n\r\n  createThing(\"a\", 100);\r\n  ```\r\n    * Could boil this down to @gcanti's [`Unionize`](https://github.com/Microsoft/TypeScript/issues/17930#issuecomment-323572209).\r\n        * ```ts\r\n          type m = { [P in \"a\" | \"b\" ]: { [Q in P]: number } }[\"a\" | \"b\"];\r\n          ```\r\n            * Becomes `type m = { a: number; } | { b: number; }`","author":{"url":"https://github.com/DanielRosenwasser","@type":"Person","name":"DanielRosenwasser"},"datePublished":"2017-08-30T18:07:36.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":2},"url":"https://github.com/18155/TypeScript/issues/18155"}