Map to Map/List conversion

[zhqu1148980644]

The spec says map/filter macro only support list type, how to apply map/filter macros to map, so we can transform a map to another map or list.

expected use case:

1. map to list

{
  "k1": "v1",
  "k2": "v2"
}.map({k, v}, {k: v})

==>

[
 {"k1": "v1"},
 {"k2": "v2"}
]

2. list to map

map([
["k1", "v1"],
["k2": "v2"]
])

==>
{
  "k1": "v1",
  "k2": "v2"
}

[matthchr]

I'm also curious about this.