Function toMap

toMap<V, K>(key: (item: V) => K | Promise<K>): Sink<V, ReadonlyMap<K, V>>
Creates a sink collecting items into a map using item values.
Type Parameters
- V
  The type of items in the stream
- K
  The type of map keys
Parameters
- key: (item: V) => K | Promise<K>
  The function to extract the key from each item
Returns Sink<V, ReadonlyMap<K, V>>
A sink that collects items into a map with keys from the key selector and items as values
Example
```
await items([{ id: 1, name: "Alice" }, { id: 2, name: "Bob" }])(toMap(x => x.id));
// Map(2) { 1 => { id: 1, name: "Alice" }, 2 => { id: 2, name: "Bob" } }
```
- Defined in sinks.ts:311
toMap<V, K, R>(
key: (item: V) => K | Promise<K>,
value: (item: V) => R | Promise<R>,
): Sink<V, ReadonlyMap<K, R>>
Creates a sink collecting items into a map using custom keys and values.
Type Parameters
- V
  The type of items in the stream
- K
  The type of map keys
- R
  The type of map values
Parameters
- key: (item: V) => K | Promise<K>
  The function to extract the key from each item
- value: (item: V) => R | Promise<R>
  The function to transform each item into a map value
Returns Sink<V, ReadonlyMap<K, R>>
A sink that collects items into a map with keys and values from the selectors
Example
```
await items([{ id: 1, name: "Alice" }, { id: 2, name: "Bob" }])(toMap(x => x.id, x => x.name));
// Map(2) { 1 => "Alice", 2 => "Bob" }
```
- Defined in sinks.ts:334