OpenEuphoria

sets for sequence.e?

• Posted by Jules <jdavy at ?sl.pipex.c?m> May 06, 2008
• 659 views

First I'd like to say thanks to Jeremy for all his hard work on the standard
library. If there is room for a few more functions, I find the following useful,
and believe others would too. I suggest they would fit better in sequence.e
rather than math.e. They are quite general and IMHO are not really "math"
functions.

The first one is a type.

set ==> ensures that the variable is a sequence wherein

each of its members only occurs once in the sequence

union ==>         s = union (s, s)

returns the union of two given sets



intersection ==>  s = intersection (s, s)

returns the intersection of two given sets


diff ==>          s = diff (s, s)

returns the difference of the two given sets; i.e.,

the inverse of the union (with the intersection removed)



is_subset ==>     i = is_subset (s, s)

returns T (1) if the first set is a subset of the second


is_superset ==>   i = is_superset (s, s)

returns T (1) if the first set is a superset of the 2nd

These are all from Rod Jackson's "set.e". But I suggest one more (not included
in his library):

mk-set ==>  s = mk_set(s)
returns a sequence with duplicate elements removed, so
each of its members occurs only once in the sequence.