gistfile1.txt

---$
- hosts: localhost$
  tasks:$
    - debug:$
        var: item$
      with_nested:$
      -$
        -$
          - 'foo'$
          - 'bah'$
      - [1,2,3]$

gistfile2.txt

$ ansible-playbook -i inventory test.yml

PLAY [localhost] **************************************************************

GATHERING FACTS ***************************************************************
ok: [localhost]

TASK: [debug ] ****************************************************************
ok: [localhost] => (item=['foo', 'bah', 1]) => {
    "item": [
        "foo",
        "bah",
        1
    ]
}
ok: [localhost] => (item=['foo', 'bah', 2]) => {
    "item": [
        "foo",
        "bah",
        2
    ]
}
ok: [localhost] => (item=['foo', 'bah', 3]) => {
    "item": [
        "foo",
        "bah",
        3
    ]
}

gistfile3.txt

---$
- hosts: localhost$
  tasks:$
    - debug:$
        var: item$
      with_nested:$
      -$
        - { foo: 'bah', test: 'wibble' }$
      - [1,2,3]$

gistfile4.txt

$ ansible-playbook -i inventory test.yml

PLAY [localhost] **************************************************************

GATHERING FACTS ***************************************************************
ok: [localhost]

TASK: [debug ] ****************************************************************
ok: [localhost] => (item=[{'test': 'wibble', 'foo': 'bah'}, 1]) => {
    "item": [
        {
            "foo": "bah",
            "test": "wibble"
        },
        1
    ]
}
ok: [localhost] => (item=[{'test': 'wibble', 'foo': 'bah'}, 2]) => {
    "item": [
        {
            "foo": "bah",
            "test": "wibble"
        },
        2
    ]
}
ok: [localhost] => (item=[{'test': 'wibble', 'foo': 'bah'}, 3]) => {
    "item": [
        {
            "foo": "bah",
            "test": "wibble"
        },
        3
    ]
}

PLAY RECAP ********************************************************************
localhost