Re-exported predicates

The following predicates are re-exported from other modules

 append(+ListOfLists, ?List)

Concatenate a list of lists. Is true if ListOfLists is a list of lists, and List is the concatenation of these lists.

Arguments:

ListOfLists

- must be a list of possibly partial lists

 flatten(+NestedList, -FlatList) is det

Is true if FlatList is a non-nested version of NestedList. Note that empty lists are removed. In standard Prolog, this implies that the atom '[]' is removed too. In SWI7, [] is distinct from '[]'.

Ending up needing flatten/2 often indicates, like append/3 for appending two lists, a bad design. Efficient code that generates lists from generated small lists must use difference lists, often possible through grammar rules for optimal readability.

See also

- append/2

Undocumented predicates

The following predicates are exported, but not or incorrectly documented.

 collect_singletons(Arg1, Arg2)