11.3.214 sort/2   ISO

Synopsis

sort(+List, -Sorted)

Sorts the elements of the list List into the ascending standard order, and removes any multiple occurrences of an element. The resulting sorted list is unified with the list Sorted.

Arguments

List

list of term, must be a proper list

Sorted

list of term

Sorted is type checked since release 4.3 for alignment with the ISO Prolog standard. Previous releases simply failed instead of reporting an error for malformed Sorted.

Exceptions

instatiation_error

type_error

List is not a proper list

type_error

Sorted cannot be unified with a proper list

Examples

| ?- sort([a,X,1,a(x),a,a(X)], L).
L = [X,1,a,a(X),a(x)]

(The time taken to do this is at worst order (N log N) where N is the length of the list.)

See Also

ref-lte-cte-sor.