Discussion on: Practical Guide to Fp-ts P6: The Do Notation

View post

Replies for: I don't think you can call both computations equivalent, because the former has a sequential control flow, whereas the latter has a nested one. Do/...

Maybe this is what you're talking about?

The extra plumbing is just a map operation to keep variables in context. If you want to do it manually here's what it does under the hood.

pipe(
  O.some(5),
  O.chain((a) =>
    pipe(
      O.none as O.Option<number>,
      O.map((b) => ({ a, b })),
    ),
  ),
  O.chain(({ a, b }) =>
    pipe(
      O.some(6),
      O.map((c) => a + b + c),
    ),
  ),
)