struct::set - Procedures for manipulating sets

package require Tcl 8.0 package require struct::set ?2.1? ::struct::set empty set ::struct::set size set ::struct::set contains set item ::struct::set union ?set1...? ::struct::set intersect ?set1...? ::struct::set difference set1 set2 ::struct::set symdiff set1 set2 ::struct::set intersect3 set1 set2 ::struct::set equal set1 set2 ::struct::set include svar item ::struct::set exclude svar item ::struct::set add svar set ::struct::set subtract svar set ::struct::set subsetof A B

The ::struct::set namespace contains several useful commands for processing finite sets.

It exports only a single command, struct::set. All functionality provided here can be reached through a subcommand of this command.

::struct::set empty set

Returns a boolean value indicating if the set is empty (true), or not (false).

::struct::set size set

Returns an integer number greater than or equal to zero. This is the number of elements in the set. In other words, its cardinality.

::struct::set contains set item

Returns a boolean value indicating if the set contains the element item (true), or not (false).

::struct::set union ?set1...?

Computes the set containing the union of set1, set2, etc., i.e. "set1 + set2 + ...", and returns this set as the result of the command.

::struct::set intersect ?set1...?

Computes the set containing the intersection of set1, set2, etc., i.e. "set1 * set2 * ...", and returns this set as the result of the command.

::struct::set difference set1 set2

Computes the set containing the difference of set1 and set2, i.e. ("set1 - set2") and returns this set as the result of the command.

::struct::set symdiff set1 set2

Computes the set containing the symmetric difference of set1 and set2, i.e. ("(set1 - set2) + (set2 - set1)") and returns this set as the result of the command.

::struct::set intersect3 set1 set2

This command is a combination of the methods intersect and difference. It returns a three-element list containing "set1*set2", "set1-set2", and "set2-set1", in this order. In other words, the intersection of the two parameter sets, and their differences.

::struct::set equal set1 set2

Returns a boolean value indicating if the two sets are equal (true) or not (false).

::struct::set include svar item

The element item is added to the set specified by the variable name in svar. The return value of the command is empty. This is the equivalent of lappend for sets.

::struct::set exclude svar item

The element item is removed from the set specified by the variable name in svar. The return value of the command is empty. This is a near-equivalent of lreplace for sets.

::struct::set add svar set

All the element of set are added to the set specified by the variable name in svar. The return value of the command is empty. This is like the method include, but for the addition of a whole set.

::struct::set subtract svar set

All the element of set are removed from the set specified by the variable name in svar. The return value of the command is empty. This is like the method exclude, but for the removal of a whole set.

::struct::set subsetof A B

Returns a boolean value indicating if the set A is a true subset of or equal to the set B (true), or not (false).

cardinality, difference, emptiness, exclusion, inclusion, intersection, membership, set, symmetric difference, union

Copyright (c) 2004 Andreas Kupries <andreas_kupries@users.sourceforge.net>