|::     $list @ $index = $value| :: set    $list $index $value
|::     $list @ $index         | :: get    $list $index
|:: del $list @ $index         | :: delete $list $index

|:: set $list $index $new :lists: $list $index $old|
    :lists: $list $index $new
    :: reset lists
|:: set $list $index $value? :lists: $x $y $z|
    :checked items: $x $y $z
|:: set $list $index $value|
    :lists: $list $index $value
    :: reset lists

|:: get $list $index :lists: $list $index $value?|
    :value: $value
    :: reset lists
|:: get $list $index? :lists: $x $y $z|
    :checked items: $x $y $z
|:: get $list $index :default value: $value?|
    :value: $value
    :: reset lists
|:: get $list $index|
    :not found: $list $index
    :: reset lists

|:: delete $list $index :lists: $list $index $value|
    :: reset lists
|:: delete $list $index? :lists: $x $y $z|
    :checked items: $x $y $z
|:: delete $list $index|
    :not found: $list $index
    :: reset lists

|:: reset lists? :checked items: $list $index $value|
    :lists: $list $index $value
|:: reset lists|

||:: foo @ 0 = bar
  :: foo @ 1 = baz
  :: foo @ 2 = quux

  :: foo @ 1 :default value: undefined
  :: del foo @ 2