Special case unary hack operator part 2

[cowboyd]

Apologies for creating a new issue. The old one was locked.

Originally posted by @js-choi in #260 (comment)

Could you clarify whether .match, .filter, and .forEach in your original example are object methods or non-method curried unary functions?

// The original post’s snippet.
stream.
  .match({ topic: 'available' }) // Is this a method call?
  .filter(status => ['started', 'exited'].includes(status.type))
  .forEach(function*(status) {
    yield send(status);
  }));
});

Assuming that .match, .filter, and .forEach are actually curried non-method curried unary functions, then—as I mentioned in #202—I am planning to pursue a proposal for a standard Function.pipe function at TC39. With that, one would write this:

Function.pipe(stream,
  match({ topic: 'available' }),
  filter(status => ['started', 'exited'].includes(status.type)),
  forEach(function*(status) {
    yield send(status);
  }),
});

Would that satisfy your use case?

Of course I forgot about types entirely when I gave my answer, so no, this would not really satisfy the use-case. It would work ok for JavaScript users, but the entire reason we're using chaining in the first place is to preserve type context for TypeScript users.

[js-choi]

Of course I forgot about types entirely when I gave my answer, so no, this would not really satisfy the use-case. It would work ok for JavaScript users, but the entire reason we're using chaining in the first place is to preserve type context for TypeScript users.

Thanks for your comment. I’m a little confused by this, though, sorry. The pipe functions in RxJS and Ramda already work with TypeScript type inference (albeit with some limitations: they have to declare type signatures for their nullary, unary, binary, ternary, etc. arity overloads).

The Function.pipe function would merely be a standardized version of the RxJS and Ramda functions in the language core, and it would easily be annotated with TypeScript types in the same way as the RxJS and Ramda versions.

See also #219.

[cowboyd]

Ah, I see. I was not aware of the Rx and Rambda method of "war-typing" but I guess that works 👍🏻