str:"hello world"
 # drop first 'l' from string
 "" fuse extract value where !index=(first extract index where value="l" from str) from str
"helo world"

 # drop all but first two 'l's from string
 "" fuse extract value where !index in (2 take extract index where value="l" from str) from str
"heo world"

 # move repeat chars to the first appearance
  "" fuse extract value by value from str
"hellloo wrd"

 # sorting
  "" fuse extract value orderby value asc from str
" dehllloorw"

 # sort uniq
 "" fuse str @ extract (first index) by value orderby value desc from str
"wrolhed "
 "" fuse extract (first value) by value orderby value desc from str
"wrolhed "

 # group with indices
 extract list (first value),index by value from str
(("h",0),("e",1),("l",2,3,9),("o",4,7),(" ",5),("w",6),("r",8),("d",10))
 raze extract (first value) dict list index by value from str
{"h":(0),"e":(1),"l":(2,3,9),"o":(4,7)," ":(5),"w":(6),"r":(8),"d":(10)}
 raze select (first value) list index by value from str
{"h":(0),"e":(1),"l":(2,3,9),"o":(4,7)," ":(5),"w":(6),"r":(8),"d":(10)}

 # only unique chars
 "" fuse extract () unless first value where 1=count index by value from str
"he wrd"