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function ok_or<T>(x: T | null, msg: string): T { if (x === null) throw new Error(msg); return x; }

• frenchy 6y ago
  This is actually more similar to what is going on above: function ok_or<T>(x: T | null, msg: string): T | Error { if (x === null) return new Error(msg); return x; } Thrown values (or exceptions if you like that term) are very much not type-safe in TypeScript.
  • moonchild 6y ago
    Does TS have syntax sugar for returning errors, as rust has? If not, I don't see what's interesting about your form.
    • frenchy 6y ago
      Sorry for the late reply. It does not. My point was mostly that the TypeScript analogs are either more of a pain or less type safe.