REBOL 3 Functions: exclude

exclude set1 set2 /case /skip size

Returns the first data set less the second data set.

Arguments:

set1 [block! string! binary! bitset! typeset!] - First data set

set2 [block! string! binary! bitset! typeset!] - Second data set

Refinements:

/case - Uses case-sensitive comparison

/skip - Treat the series as records of fixed size

size [integer!]

Description

Returns the elements of the first set less the elements of the second set. In other words, it removes from the first set all elements that are part of the second set.

lunch: [ham cheese bread carrot]
dinner: [ham salad carrot rice]
probe exclude lunch dinner
[cheese bread]

probe exclude [1 3 2 4] [3 5 4 6]
[1 2]

string1: "CBAD"    ; A B C D scrambled
string2: "EDCF"    ; C D E F scrambled
probe exclude string1 string2
"BA"

items: [1 1 2 3 2 4 5 1 2]
probe exclude items items  ; get unique set
[]

str: "abcacbaabcca"
probe exclude str str
""

Note that performing this function over very large data sets can be CPU intensive.