Task

Pass a function     as an argument     to another function.



Related task

   First-class functions


  [ over [] = iff drop done
     dip 
       [ behead swap
        ' [ witheach ] ]
     nested join do ]       is fold   ( [ x --> x )

  [ ' [ [ ] ] rot join swap
    nested
    ' [ nested join ] join
    fold ]                  is map    ( [ x --> [ )

  [ ' [ [ ] ] rot join swap
    nested ' dup swap join
    ' [ iff [ nested join ]
        else drop ] join
    fold ]                  is filter ( [ x --> [ )

