oracular (3) struct_set.3tcl.gz

Provided by: tcllib_1.21+dfsg-1_all bug

NAME
       struct::set - Procedures for manipulating sets


SYNOPSIS
       package require Tcl  8.0

       package require struct::set  ?2.2.3?

       ::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

________________________________________________________________________________________________________________


DESCRIPTION
       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.

       Note: As of version 2.2 of this package a critcl based C implementation is available. This implementation
       however requires Tcl 8.4 to run.


COMMANDS
       ::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. If the variable named by svar
              does not exist it will be created.

       ::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. If the variable named by svar does not exist it will be created.

       ::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).


REFERENCES
BUGS, IDEAS, FEEDBACK
       This document, and the package it describes, will undoubtedly contain bugs and  other  problems.   Please
       report  such in the category struct :: set of the Tcllib Trackers [http://core.tcl.tk/tcllib/reportlist].
       Please also report any ideas for enhancements you may have for either package and/or documentation.

       When proposing code changes, please provide unified diffs, i.e the output of diff -u.

       Note further that attachments are strongly preferred over inlined patches. Attachments  can  be  made  by
       going  to the Edit form of the ticket immediately after its creation, and then using the left-most button
       in the secondary navigation bar.


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


CATEGORY
       Data structures


       Copyright (c) 2004-2008 Andreas Kupries <andreas_kupries@users.sourceforge.net>