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Types are pretend in TypeScript and Flow the same way that types are pretend in any other typed language. Types are used at compile-time and not runtime in both

Types are pretend in TypeScript and Flow the same way that types are pretend in any other typed language. Types are used at compile-time and not runtime in both cases.

egeozcan 10y ago
In contrast to many typed languages, currently in Typescript, you can't do any kind of reflection so runtime really has no access to the type system. Well, I still love TS though.
- johnfn 10y ago
  There is the possibility of decorators for stuff like this. Angular makes a lot of use of them.
  - egeozcan 10y ago
    But isn't that some sort of repetition? I don't know how Angular does this so I'm really asking.
    - johnfn 10y ago
      Well, it depends on the sort of reflection you want. Decorators get a decent amount of knowledge about the code.
tomelders 10y ago
Are they used at compile time with TS or Flow? I thought they were just stripped out.
- wtetzner 10y ago
  Well, I assume they're at least used at type-checking time, which most people consider to be a subset of compile time.
recursive 10y ago
In most other languages, type casts are assertions that can fail. Not typescript.