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7928 :: Sequence item del vs. delete?

• Neodim (orginal) [2021-05-05T10:44:48+02:00] view original

  hello,

  just faced curious issue:

  
  var a = @[1,2,3,4,5]
  
  a.delete(0)
  
  echo a # returns @[2, 3, 4, 5] as expected
  Run

  while

  
  var a = @[1,2,3,4,5]
  a.del(0)
  echo a # returns @[5, 2, 3, 4] which is little bit confusing
  Run

  Just curious is it a bug or feature?

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• Araq (orginal) [2021-05-05T10:46:59+02:00] view original

  Not a bug, documented here:

  https://nim-lang.org/docs/system.html#system-module-seqs

  https://nim-lang.org/docs/system.html#del,seq[T],Natural

  https://nim-lang.org/docs/system.html#delete%2Cseq%5BT%5D%2CNatural

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• Neodim (orginal) [2021-05-05T11:00:56+02:00] view original

  Got it, thanks. But then what is a special purpose of such function?

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• doofenstein (orginal) [2021-05-05T11:06:22+02:00] view original

  Couldn't render post #50474.

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• ElegantBeef (orginal) [2021-05-05T11:07:06+02:00] view original

  When order doesnt matter and you want a performant method for removing an element. Since it just moves a single element to the index to remove it's cheaper than moving all elements after the one you removed down a single index.

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• japplegame (orginal) [2021-05-06T09:34:42+02:00] view original

  The function name del is completely confusing.

  It would be better to use something like deleteUnstable.

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• xigoi (orginal) [2021-05-06T09:46:24+02:00] view original

  I believe Rust has swap_remove, which is a very descriptive name.

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• Araq (orginal) [2021-05-06T10:45:13+02:00] view original

  I'm pretty sure when I invented del Rust didn't exist...

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