max_by.yml

name: max_by
topic: math
args:
  required:
  - name: elements
    type: array
  - name: expr
    type: [expression->number, expression->string]
returns:
  type: any
desc: |
  Return the maximum element in an array using the expression `expr` as the
  comparison key.  The entire maximum element is returned.
  Below are several examples using the `people` array (defined above) as the
  given input.
examples:
  test5:
    context: &data
      people:
      - {age: 20, age_str: '20', bool: true, name: a, extra: foo}
      - {age: 40, age_str: '40', bool: false, name: b, extra: bar}
      - {age: 30, age_str: '30', bool: true, name: c}
      - {age: 50, age_str: '50', bool: false, name: d}
      - {age: 10, age_str: '10', bool: true, name: 3}
    args: [people, '&age']
    returns: {age: 50, age_str: '50', bool: false, name: d}
  test6:
    context: *data
    args: [people, '&age_str']
    returns: {age: 50, age_str: '50', bool: false, name: d}
  test7:
    context: *data
    args: [people, '&bool']
    error: invalid-type
  test8:
    context: *data
    args: [people, '&extra']
    error: invalid-type
  test9:
    context: *data
    args: [people, '&to_number(age_str)']
    returns: {age: 50, age_str: '50', bool: false, name: d}
  test3:
    context: *data
    args: [people, '&age_str']
    error: invalid-type
  test4:
    context: *data
    args: [people, age]
    error: invalid-type