# Data Structures

- The Sequence interface

The standard instances are named `AtomSeq`, `IntSeq`, `RefSeq`, and `TextSeq`.

- The Atom interface
- The List interface

The standard instances are named `AtomList`, `IntList`, `RefList`, and `TextList`.

- The ListSort interface

The standard instances are named `AtomListSort`, `IntListSort`, `RefListSort`, and `TextListSort`. `AtomListSort` and `RefListSort` are useful only if you supply a non-default comparison procedure.

- The Sx interface
- The Table interface

The standard instances are named `xyTbl`, for all combinations of `x` and `y` in the set `{Atom, Int, Ref, Text}`. The instances with `x = Ref` are useful only if you define a subtype overriding the `keyHash` and `keyEqual` methods.

- The SortedTable interface

The standard instances are named `SortedxyTbl`, for all combinations of `x` and `y` in the set `{Atom, Int, Ref, Text}`. The instances with `x = Atom` and `x = Ref` are useful only if you define a subtype overriding the `keyCompare` method.

- The Bundle interface