Map arrays of objects

To map every element of an array, scope with source and pair inside each:

/people:
  source: /contributors
  each:
    /name: /fullName
    /role: { source: /role, default: author }

{
  "contributors": [
    { "fullName": "Grace Hopper", "role": "editor" },
    { "fullName": "Emmy Noether" }
  ]
}

becomes:

{
  "people": [
    { "name": "Grace Hopper", "role": "editor" },
    { "name": "Emmy Noether", "role": "author" }
  ]
}

Each element maps against a fresh target. Pointers inside each read from the element.

To read one element, point into it by index:

/lead: /contributors/0/fullName

To fall back across fields, use an array descriptor. The first defined result wins, per element:

/people:
  source: /contributors
  each:
    /name: ['/nickname', '/fullName']