Function seek

seek<V>(): Sink<V, V>
Creates a sink retrieving the first item of the feed, failing if it carries none.

Consumption stops at the first item, leaving the rest of the feed unconsumed; the first item meeting a condition is retrieved by drawing from a filter() upstream.

An empty feed fails the sink instead of resolving to undefined as find does, so the item handed back is usable as is, with no check to tell a missing item from an undefined item the feed legitimately carries.
Note
- Incremental: a single item is drawn, so an infinite feed completes.
- Streaming: the item is handed back as it is drawn, none retained.
- Stateless: the outcome rests on the first item alone.
Type Parameters
- V
  The type of items in the feed
Returns Sink<V, V>
A sink resolving to the first item of the feed
Throws
Error If the feed carries no item
Example
```
await pipe(
  (items([1, 2, 3, 4, 5]))
  (seek())
);  // 1

await pipe(
  (items([1, 2, 3, 4, 5]))
  (filter(n => n > 3))
  (seek())
);  // 4
```
- Defined in sinks/seek.ts:56