distinct

Distinct

?x

distinct, a.k.a. unique or uniq, returns a copy of its argument without duplicate items (according to the definition of match). K9 additionally sorts the result.

 ?"abracadabra"
"abrcd"

 ?"abracadabra" /k9
"abcdr"

{x@&(x?x)=!#x}  /k9 unsorted unique