"Hello World in Smalltalk"

'Hello World' out.

" This must be inserted into the class Array as an instance method "


quicksort: l to: r
" sorts the array between l and r after the quicksort method 
  by Michael Neumann 1998
"
| m il ir temp |
   (r > l) ifTrue: [
      m := self at: ((l + r) // 2).
      il := l.
      ir := r.
      [
         [(self at: il) < m] whileTrue: [il := il + 1.].
         [(self at: ir) > m] whileTrue: [ir := ir - 1.].
         (il < ir) ifTrue: [
            " swap "
            temp := self at: il.
            self at: il put: (self at: ir).
            self at: ir put: temp.
         ].
      ] doUntil: [il >= ir.].
      self quicksort: l to: (il - 1).
      self quicksort: (il + 1) to: r.
   ].
^self.

| someNumbers |
someNumbers := {1 2 3 4 5 6 7 8 9 10}
(someNumbers collect: [:i| i squared.]) out.

1 to: 10 do: [ :i | Transcript show: (i squared)]