lists:list_to

swipl
- library

list_to_set(+List, ?Set) is det

True when Set has the same elements as List in the same order. The left-most copy of duplicate elements is retained. List may contain variables. Elements E1 and E2 are considered duplicates iff E1 == E2 holds. The complexity of the implementation is N*log(N).

Errors: - List is type-checked.
See also: - sort/2 can be used to create an ordered set. Many set operations on ordered sets are order N rather than order N**2. The list_to_set/2 predicate is more expensive than sort/2 because it involves, two sorts and a linear scan.
Compatibility: - Up to version 6.3.11, list_to_set/2 had complexity N**2 and equality was tested using =/2.