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557 :: Initializing seq[seq[int]]

• Cyther606 (orginal) [2014-09-16T03:28:08+02:00] view original

  My seq[seq[int]] len varies between 1 and 10. Here I would need to delete(threads, 0, 0) to purge the extraneous @[0, 0] which gets added with newSeqseq[int]. newSeqseq[int] works in some places to avoid having the first position filled, but not here.

  let
    pt1x = 12
    pt1y = 3
    pt2x = 11
    pt2y = 2
    pt3x = 10
    pt3y = 2
  
  var threads = newSeq[seq[int]](1)
  
  threads[0].newSeq(2)
  threads.add(@[pt1x, pt1y])
  threads.add(@[pt2x, pt2y])
  threads.add(@[pt3x, pt3y])
  
  echo threads # @[@[0, 0], @[12, 3], @[11, 2], @[10, 2]]
  Run

  # keeping the rest of the code the same
  # removing the int from newSeq call produces runtime error
  var threads = newSeq[seq[int]]()
  
  Traceback (most recent call last)
  threads.nim(11)          threads
  Error: unhandled exception: index out of bounds [EInvalidIndex]
  Run

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• Araq (orginal) [2014-09-16T09:22:15+02:00] view original

  What is your problem here? If you don't want threads[0], don't newSeq(1)!

  
  
  var threads = newSeq[seq[int]](0)
  
  threads.add(@[pt1x, pt1y])
  threads.add(@[pt2x, pt2y])
  threads.add(@[pt3x, pt3y])
  Run

  Also possible:

  
  
  var threads = @[
    @[pt1x, pt1y],
    @[pt2x, pt2y],
    @[pt3x, pt3y]]
  Run

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