![\"better-result](\"https://better-result.dev/logo.svg\"){kind=logo}
\n\n \n
Lightweight Result type for TypeScript with generator-based composition.
\n\n\n Documentation ·\n Quickstart ·\n API reference ·\n Migrate from 2.x\n
\n\n- **Make failures explicit:** TypeScript shows what a function returns when it succeeds and what can go wrong.\n- **Write multi-step workflows in order:** `yield*` passes successful values to the next step and stops on the first failure.\n- **Keep expected failures separate from bugs:** handle expected failures as normal return values; unexpected exceptions still throw.\n\n```ts\nimport { Result, TaggedError } from \"better-result\";\n\nclass InvalidPort extends TaggedError(\"InvalidPort\")<{\n input: string;\n message: string;\n}> {}\n\nconst parsePort = (input: string) => {\n const port = Number(input);\n return Number.isInteger(port) && port > 0 && port <= 65_535\n ? Result.ok(port)\n : Result.err(new InvalidPort({ input, message: \"Expected a port from 1 to 65535\" }));\n};\n\nconst message = parsePort(process.env.PORT ?? \"3000\")\n .map((port) => `http://localhost:${port}`)\n .match({\n ok: (address) => `Listening at ${address}`,\n err: (error) => `Invalid configuration: ${error.message}`,\n });\n```\n\n`parsePort` returns `Result