Map Selector API

[emil14]

• Maybe take str | list<str> as a k as input
• Maybe return MapResult as an output where

MapResult<T> struct {
  k str
  v T
}

Maybe k should be list<str>

Maybe even like this

MapResult<K str | list<str>, V> struct {
  k K
  v V
}

...

mapSelect<K str | list<str>, V> (m map<V>, k K) (MapResult<K, V>)

So we can say

nodes { select mapSelector<list<str>, int> }
net {
  (SomeMapType { foo: bar: {} }) -> select.v
  (list<str> ['foo', 'bar']) -> select.k
  select.v -> ...
}