René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Add support for literal type subtraction ","articleBody":"Now we have [Mapped Types](https://github.com/Microsoft/TypeScript/pull/12114) and [keyof](https://github.com/Microsoft/TypeScript/pull/11929), we could add a subtraction operator that only works on literal types:\r\n\r\n```typescript\r\ntype Omit\u003cT, K extends keyof T\u003e = {\r\n    [P in keyof T - K]: T[P];\r\n};\r\n\r\ntype Overwrite\u003cT, K\u003e = K \u0026 {\r\n    [P in keyof T - keyof K]: T[P];\r\n};\r\n\r\ntype Item1 = { a: string, b: number, c: boolean };\r\ntype Item2 = { a: number };\r\n\r\ntype T1 = Omit\u003cItem1, \"a\"\u003e // { b: number, c: boolean };\r\ntype T2 = Overwrite\u003cItem1, Item2\u003e // { a: number, b: number, c: boolean };\r\n```","author":{"url":"https://github.com/alinhle","@type":"Person","name":"alinhle"},"datePublished":"2016-11-14T09:10:33.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":90},"url":"https://github.com/12215/TypeScript/issues/12215"}