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Fuzion • Idioms • Idiom # 119: Deduplicate list

Idiom # 119: Deduplicate list

See programming-idioms.org:

Code

# preserving order
#
x := for
       r list String := nil, if e ∈ s then r
                                      else cons e r
       s := set_of_ordered (Sequence String).type.empty, s.add e
       e in x
     else
       r.reverse

# not preserving order
#
x := set_of_ordered x

What are effects?

Running Example

ex119 is

  # preserving order
  #
  x := [ "b", "a", "b", "c" ]
  x := for
         r list String := nil, if e ∈ s then r
                                        else cons e r
         s := set_of_ordered (Sequence String).type.empty, s.add e
         e in x
       else
         r.reverse
  say x

  # not preserving order
  #
  x := [ "b", "a", "b", "c" ]
  x := set_of_ordered x
  say x

What are effects?

next: Idiom # 120: Read integer from stdin