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1436 :: seq.delete() is strange

• takaomag (orginal) [2015-07-10T08:07:30+02:00] view original

  In my environment, seq.delete behaves strangely. Something wrong?

  ar
    s = @[0, 1, 2]
  
  echo("Before import sequtils")
  
  assert s.len == 3
  s.delete(0)
  echo("len=", $s.len)
  assert s.len == 2
  s.delete(1)
  echo("len=", $s.len)
  assert s.len == 1
  s.delete(0)
  echo("len=", $s.len)
  assert s.len == 0
  
  
  import sequtils
  
  s = @[0, 1, 2]
  
  echo("After import sequtils")
  
  assert s.len == 3
  s.delete(0)
  echo("len=", $s.len)
  assert s.len == 2
  s.delete(1)
  echo("len=", $s.len)
  assert s.len == 1  # Error: unhandled exception: len(s) == 1  [AssertionError]
  s.delete(0)
  echo("len=", $s.len)
  assert s.len == 0
  Run

  Environment:

  
  gcc version: 5.1.0
  Nim Compiler Version 0.11.2 (2015-07-10) [Linux: amd64]
  Copyright (c) 2006-2015 by Andreas Rumpf
  
  git hash: 45b6082c12dd6fc90a3dd3ca97e1ba157c3d6464
  active boot switches: -d:release
  Run

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• jyapayne (orginal) [2015-07-10T08:36:12+02:00] view original

  Looks like sequtils redefines the delete proc. See here.

  This means that you either need to use s.delete(0, 1) or system.delete(s, 0) to achieve the same effect. The docs for the original system.delete are here.

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• takaomag (orginal) [2015-07-10T08:52:32+02:00] view original

  Oh, I see. I had checked the signature on github（devel).

  On github(devel), the signature of sequtils.delete is

   delete*[T](s: var seq[T]; first, last: Natural) =
  Run

  .

  But in my current stdlib source (and docs),

   delete*[T](s: var seq[T], first=0, last=0) =
  Run

  Thanks!

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• Varriount (orginal) [2015-07-10T08:57:07+02:00] view original

  That... Should probably be fixed. It's more than likely the intent for the delete procedure in sequtils was to simply enable deletion of a section of the sequence. This would probably be fixed by removing the default values for sequtils.delete, so that using a single statement matches the system.delete .

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• takaomag (orginal) [2015-07-10T09:07:22+02:00] view original

  2 days ago, the fix has been committed by Araq. Thanks!

  https://github.com/nim-lang/Nim/commit/a2b8b8b0dd3f9d80e897033ff9cd71f01ee38310

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