.. _library_arrangements:

arrangements

This library provides predicates for generating and querying arrangements over lists. Arrangements are ordered selections of a given length with element repetition allowed. The following categories of predicates are provided:

• Generation operations - Predicates for generating arrangements.
• Ordering variants - Predicates that support an additional order argument (default or lexicographic) for controlling output order.
• Distinct-value generation - Predicates for generating arrangements while deduplicating equal-valued results.
• Indexed access - Predicates for direct access to arrangements at specific positions, including distinct arrangements.
• Lexicographic stepping - Predicates for navigating arrangements in lexicographic order.
• Counting operations - Predicates for counting arrangements and distinct arrangements.
• Random selection - Predicates for randomly selecting and sampling arrangements and distinct arrangements.

  Dedicated cartesian_products, permutations, combinations, multisets, derangements, partitions, and subsequences libraries are also available for focused APIs on related operations.

API documentation

Open the `../../apis/library_index.html#arrangements <../../apis/library_index.html#arrangements>`__ link in a web browser.

Loading

To load all entities in this library, load the loader.lgt file:

::

| ?- logtalk_load(arrangements(loader)).

Testing

To test this library predicates, load the tester.lgt file:

::

| ?- logtalk_load(arrangements(tester)).