Identity lists

Author(s): Francisco Bueno.

Version: 1.11#145 (2004/1/1, 14:1:41 CET)

The operations in this module handle lists by performing equality checks via identity instead of unification.

Usage and interface (`idlists`)

Library usage: :- use_module(library(idlists)).
Exports:
- Predicates: member_0/2, memberchk/2, list_insert/2, add_after/4, add_before/4, delete/3, subtract/3, union_idlists/3.

PREDICATE: member_0/2:

member_0(X, Xs)

True iff memberchk/2 is true.

PREDICATE: memberchk/2:

memberchk(X, Xs)

Checks that X is an element of (list) Xs.

PREDICATE: list_insert/2:

Usage: list_insert(List, Term)

Description: Adds Term to the end of (tail-opened) List if there is not an element in List identical to Term.
The following properties should hold at call time: List is a free variable. (term_typing:var/1) Term is currently a term which is not a free variable. (term_typing:nonvar/1)

PREDICATE: add_after/4:

Usage: add_after(L0, E0, E, L)

Description: Adds element E after the first element identical to E0 (or at end) of list L0, returning in L the new list.
The following properties should hold at call time: L0 is currently a term which is not a free variable. (term_typing:nonvar/1) E0 is currently a term which is not a free variable. (term_typing:nonvar/1) E is currently a term which is not a free variable. (term_typing:nonvar/1) L is a free variable. (term_typing:var/1)

PREDICATE: add_before/4:

Usage: add_before(L0, E0, E, L)

Description: Adds element E before the first element identical to E0 (or at start) of list L0, returning in L the new list.
The following properties should hold at call time: L0 is currently a term which is not a free variable. (term_typing:nonvar/1) E0 is currently a term which is not a free variable. (term_typing:nonvar/1) E is currently a term which is not a free variable. (term_typing:nonvar/1) L is a free variable. (term_typing:var/1)

PREDICATE: delete/3:

Usage: delete(List, Element, Rest)

Description: Rest has the same elements of List except for all the occurrences of elements identical to Element.
The following properties should hold at call time: List is currently a term which is not a free variable. (term_typing:nonvar/1) Element is currently a term which is not a free variable. (term_typing:nonvar/1) Rest is a free variable. (term_typing:var/1)

PREDICATE: subtract/3:

Usage: subtract(Set, Set0, Difference)

Description: Difference has the same elements of Set except those which have an identical occurrence in Set0.
The following properties should hold at call time: Set is currently a term which is not a free variable. (term_typing:nonvar/1) Set0 is currently a term which is not a free variable. (term_typing:nonvar/1) Difference is a free variable. (term_typing:var/1)

PREDICATE: union_idlists/3:

Usage: union_idlists(List1, List2, List)

Description: List has the elements which are in List1 but are not identical to an element in List2 followed by the elements in List2.
The following properties should hold at call time: List1 is currently a term which is not a free variable. (term_typing:nonvar/1) List2 is currently a term which is not a free variable. (term_typing:nonvar/1) List is a free variable. (term_typing:var/1)