Unique()
FUNCTION: unique(<list>[,<sorttype>[,<sep>,<osep>]])
Removes duplicate elements from <list>, preserving the first occurrence of each value (it does not reorder the list). Elements are compared literally (no wildcarding). The optional <sorttype> selects how values are compared, using the same type codes as sort(): ‘a’ case-sensitive ASCII (the default), ‘i’ case-insensitive, ’n’ integer, ‘f’ floating-point, ’d’ dbref, ‘u’ Unicode collation, and ‘c’ case-insensitive Unicode. <sep> specifies the input delimiter and defaults to a space, while <osep> sets the output delimiter and defaults to <sep>.
Examples:
> say unique(a b a c b d)
You say, "a b c d"
> say unique(a A b a, i)
You say, "a b"
> say unique(1 2 2.0 3, f)
You say, "1 2 3"
> say unique(3 1 2 1 3, n, , |)
You say, "3|1|2"