Mark S. Miller schrieb:
Something strange and bizarre that Jafar and I just discovered after the
TC39 meeting:
We all know that there are a set of conventional combinators, like
flatMap, that work fine for iterators.
Iterators are uni-directional. Generators are bi-directional. (As Jara
observes: Generator implements Iterator, Observer)
We thought that these combinators did not apply to generators in their
full bidirectional glory. We were wrong.
Flatmap of generators can approximately be modeled in terms of "yield*
wrap"
So you have a signature of `Iterable<Generator<i, o, r>> -> Generator<i,
o, r>` in mind, not a monadic `join`-like function that takes a generator?
flatMap([g1, g2]) is equivalent to
(function*() {
yield* wrap(g1, function.sent); // result of g1 ignored!
return yield* g2;
}())
Maybe it should be
(function*() {
return [yield* wrap(g1, function.sent), yield* g2];
}())
with `Iterable<Generator<i, o, r>> -> Generator<i, o, Iterable<r>>`?
Bergi
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